Why is the creation of water from the combustion of hydrocarbons not listed as a cause for rising sea levels?

1.2 x 10^13 kg equals 12,000,000,000,000 l water. One liter equals 0.001 m³, while one km³ equals one billion (1 x 10^9) m³. So we're supposedly adding 12 km³ water to the atmosphere per year.
According to wikipedia the total oceanic surface is about 361,900,000 km². If we spread the added amount of water over all the oceans, we end up with a sea level rise of 0,03316 mm per year. The german wikipedia page on sea level rise claims - based on the  5th chapter of the Fourth Assessment Report by the IPCC from 2007 - that the annual sea level rise between 1993 and 2003 due to thermal expansion was about 1,6 ± 0,50 mm.
Since we didn't take into account sinking surface above oceanic hydrocarbon sources or the increased atmospheric capacity for water vapour due to heating, which both are connected to the effect you are interested in, I'd estimate there is an existing, but almost negligible contribution to sea level rise. Other effects contribute way more - and all of them will likely peter out, once we reduce fossil fuel consumption significantly.


About an alternative type of wind energy facility

This has been tried to some extent; Strata in London was a skyscraper that was built with three wind turbines at the top, with a deliberate design to funnel wind into them. There are other examples.

Siting renewable energy generation in cities is very attractive, partly because many people feel that the "industrial" feel fits better there, but also because it locates sources of generation close to sources demand. For some other technologies, such as photovoltaics, this is indeed a good approach. However, it doesn't tend to work out that way for wind.

There are three main disadvantages to urban wind:

"Dirty air" : Not what it literally sounds like (that's also true in cities, but wind turbines don't mind). The wind that is funnelled through, around and above buildings is sometimes accelerated, but it is also made turbulent, and wind turbines do not like turbulent flow. Turbulence increases the unwanted forces that turbines experience (i.e. forces that do not help them make electricity), and makes them less efficient.
Economies of scale: The amount of power that a wind turbine can generate, in a given wind speed, is proportional to the square of its diameter. Which is to say, size matters. In the countryside, onshore rotors commonly reach 80m diameter (offshore are much larger). In cities, this size would not be practical or acceptable. That means that a much larger number of turbines would be needed to generate as much power, which would be more expensive and have more visual impact.
It isn't all that windy: The power that a turbine of a given diameter can generate is proportional to the cube of the wind speed. Because of this, small differences in wind speed are very important to wind farms. Most cities simply do not experience such high windspeeds as rural hilltops do.

A fourth reason may be public acceptance; while people may view a few token turbines on rooftops as a good thing, the quantity needed to make a substantial contribution to national demand would drastically change a city's skyline, and might meet with disapproval similar to many rural wind farms. However, I have no evidence for this.


Uranium is primarily lithophilic (it readily combines chemically with oxygen), but also is chalcophilic (it readily combines chemically with sulfur). It definitely is not siderophilic (it does not readily dissolve in molten iron). The first two means that uranium compounds are easily formed, which are of course much less dense than is pure uranium. That uranium is not siderophilic means that the mechanisms that led to the differentiation of the Earth had a lesser effect on uranium than it did on metals that easily alloy with iron.


How can I merge weather data from different time zones?

Using your example of 10 AM EST and 9 AM CST, those are both exactly the same time and another way of specifying that time is 1500 UTC or 15Z (Z being historical for GMT, for your application the difference between UTC and GMT is negligible).

If you know the location of your stations then you can know their timezone.  To make inter-comparisons between stations meaningful you need to reference them all at the same time and the easiest way is to express them in UTC.  You are correct that this is just a nomenclature change but this gives all locations a common reference anywhere on earth.  All meteorological data natively uses UTC and has been since telegraph was invented and weather data was exchanged over large distances.


Are greenhouse effect and ozone depletion correlated?

Ozone protects us by absorbing ultraviolet radiation
As shown in this Chemistry.SE answer, ozone breaks upon incidence of various energies of UV radiation to form oxygen, which itself is somewhat effective at blocking UV radiation at other energies. THe key is that the incident UV radiation transfers its energy to the reaction products in order to break the bonds holding ozone (or oxygen) together.
As opposed to protecting us from UV, the only way for ozone to protect us from global warming is for it to reflect the incident UV radiation back into space. That is not what it does. UV that enters the Earth's atmosphere and interacts with the ozone stays in the Earth's atmosphere.
Therefore, your question premise is flawed when you say "if ozone layers gets smaller, more UV radiation enters on Earth." That is not true, because UV radiation that that enters the Earth will be absorbed by something, whether it is ozone or the rest of the atmosphere or the ground.
Global warming deals with infrared radiation
Furthermore, 'global warming' is primarily concerned with radiation heading outwards in the infrared band. IR radiation emitted from the ground is blocked by CO$_2$ in the atmosphere and prevented from escaping into space. So the effect of ozone on UV radiation will have little to no effect on 'global warming'.


Confused about whether physical impact is 'erosion'

I'm assuming here that you're asking whether you can apply the term ‘erosion’ to the damage your stone suffered, rather than the damage your floor suffered. In this case, the applicability of the term hinges not so much on who's doing it as on what it's happening to. In geology, the term ‘erosion’ is usually applied to land surfaces rather than individual, loose bits of rock. For instance, the Oxford English Dictionary has:

  erode, v.
  2. Geol. Of the action of currents, glaciers, etc.:
  a. To wear away; to eat out.
  b. To form (a channel, etc.) by gradual wearing away.

Nichols (2009), more concisely, says

  ... erosion is the removal of regolith material.

Once your stone is picked up and taken into your house, it's no longer part of the regolith material, although the surface you took it from was itself eroded by the stone's removal.

In the literature, human influences aren't usually excluded when discussing ‘erosion’. For example, the term is often applied when discussing how footpaths are worn down by human use (see e.g. Coleman, 1981).

So, if your dropped stone chipped a bit out of your floor, you might try to claim that as erosion, but only if you're prepared to argue that your floor constitutes regolith!

If you want a geologically appropriate term for what happened to your stone, abrasion would probably cover it. Allaby (2008) has this definition:

  abrasion (corrasion): The erosive action that occurs when rock particles of varying size are dragged over or hurled against a surface.

The use of ‘erosive’ in the definition perhaps doesn't make it entirely clear that this can apply to the particles as well as the surface itself, but it's easy to check that ‘abrasion’ is indeed used in this way in the literature. For example, again from Nichols (2009):

  ... sharp edges tend to be chipped off first, the abrasion smoothing the surface of the clast.

Responses to comments

  Does this mean that when my stone suffers abrasion, it is now destroyed?

No, not at all. ‘Abrasion’ just means that some material has been removed from your stone by mechanical action. Of course it would be possible to abrade your stone so much that it was completely destroyed, but this isn't implied by the term ‘abrasion’ itself.

  What would happen to the damage over time? Will weathering try to repair it?

In general, material removed from a piece of rock will not be repaired by natural processes. In some natural environments, new minerals may precipitate in a crack left by abrasive damage, but this won't happen to a piece of rock sitting on a shelf in your house :). In the natural course of the rock cycle, an abraded fragment of rock may eventually be ‘recycled’ rather than being ‘repaired’ -- for example, it may be incorporated into a conglomerate, or buried, melted, and recrystallized as a new igneous rock.

References

Allaby, M. (2008). Oxford Dictionary of Earth Science. Oxford University Press.

Coleman, R. (1981). Footpath erosion in the English Lake District. Applied Geography, 1(2), 121-131.

Nichols, G. (2009). Sedimentology and stratigraphy. John Wiley & Sons.


How much worse is the typical subway air, compared to street-level air pollution, in a typical city?

Depends on what type of pollution you are talking about

Moreno et al., 2015 studied this problem in Barcelona, and compared Metro (subway) to trams, buses, and walking in various parts of the city. There is a massive overabundance of data in this paper that mostly speaks for itself, but let me summarize.

The subway was in first place or last place in most measures; it was the only system that didn't occupy the environment of the city streets. So these comparisons are probably exactly what you are looking for. Subway air had the lowest count of particulate matter, and the highest modal particle size; both of these are good. However, at the same time, the PM$_{2.5}$ (fine particulates which are particularly dangerous carcinogens) for subway and bus were notably higher than for tram and walking.

The black carbon levels were in the middle of the road; lower than for pedestrians but higher than bus or tram. However, the authors note that black carbon may have been overestimated for the subways; so these levels could have been lower.

Carbon monoxide is largely related to combustion engine usage; CO levels were lowest on the electric trams, and higher on the other modes of transportation. Carbon Dioxide, on the other hand, is largely related to other passengers breathing; CO$_2$ was highest on the crowded vehicles and much lower for pedestrians. CO$_2$, unlike the others, I don't think is a chronic health risk at the observed concentrations.

Conclusion

There is a lot of information in that paper, and I am not really qualified to judge the health risks from one factor against another. I can note that in no health measures does the subway have the worst air quality between the four transportation modes; and there is no other mode that has better air quality than the subway in all measures.

I suppose it is safest to say that, in a statistical sense across multiple measures, the subway air is not significantly more unhealthy than street level air.


How is the distribution of Argo floats managed over the Earth's oceans?

I think, there are two factors which prevent the forming of clusters of floats:

The floats' lifespan. Batteries supposedly last for four years, then the floats become debris which sink to the bottom of the ocean (yeah, not that great from an environmentalist point of view). So the lifespan of the battery prevents the floats from clustering.
The introdcution of new floats. Derelic floats are replaced by new ones to keep the network working. Naturally, these new floats are placed somewhere in the ocean, where they don't end up immediately in a gyre but will most likely provide the most possible diversity of data.


In an Earth-like planet with no history of carbon-based life forms, would there be limestone?

I'd have to say, yes. Once life evolved in the world's oceans, the vast majority of limestone formation has been through the organic process. However, before life did evolve, limestone formed through an inorganic process where rain water falling through a CO2-rich atmosphere reacted to form a weak carbonic acid solution that then reacted with calcium-containing minerals to form calcites. This then washed into the world's oceans to form limestone deposits.From gsu.edu:

  Limestone may form inorganically or by biochemical processes.
  Another form of limestone of inorganic origin is oolitic limestone, limestone formed from small spherical grains called ooids.

In an paper from Stanford.edu:

  Carbonic acid dissociated to form hydrogen ions, which found their way into the structures of weathering minerals, and bicarbonate, which was carried down rivers and streams to be deposited as limestone and other minerals in ocean sediments.

So even in a world devoid of carbon-based life, limestone could still form if it had a CO2-rich atmosphere, water (and thus rain), and calcium-containing crustal deposits. Though the paper from Stanford is theoretical, note that this does not mean hypothetical and is (I believe) based on solid science.


Would pollution really take a lot of years to disappear from the atmosphere once people stop producing them?

[I apologise for this long & somewhat scrappy answer.  It may contain significant errors, for which I apologise as well.]

How long something persists in the atmosphere once it's there depends, obviously, on how it gets removed from the atmosphere and also if anything is adding it to the atmosphere.  Different things we might consider pollutants will have different lifetimes, often very different, and it's confusing to lump them together as 'pollution'.

However there is a very important distinction to be made:

one thing we could care about is 'how long do we expect an individual atom/molecule/particle of $x$ to remain in the atmosphere before it leaves it?'
another thing we might care about is 'how should we expect the concentration of $x$ to behave in the atmosphere over time?'

These two things are not the same.  They are not the same because, even considering only 'natural' processes (which we might define as 'processes not resulting from the burning of fossil fuels or industrial activity') absorption is not all that happens: emission also happens.

The thing that is interesting to know is generally the second: 'how does the concentration of $x$ go over time?'  That's because no-one actually cares whether a given unit of something stays in the atmosphere for long: they care about how much of it there is in the atmosphere: I don't care whether I'm breathing some particular oxygen molecules, I care that there is enough oxygen in the atmosphere that I can breathe.

Removal mechanisms

There are at least three mechanisms for removing something from the atmosphere.

It may not be stable in the atmosphere.  A good example of this is methane, which gets turned into other things over a few years.  If methane emissions (including natural ones) stopped it would essentially all disappear within a few decades at most.
It may leave the atmosphere by falling out of it or by being involved in precipitation.  This is true for aerosols (particulates) in the atmosphere: aerosols with large particle sizes really fall out of the atmosphere, aerosols with very small particle sizes get removed by precipitation and intermediate size ones experience both processes.
It may get actively absorbed by something on the surface.

A fourth mechanism is 'it may escape to space' but this is not a significant process anything interesting here, so I'll ignore it.  There may be other mechanisms I have not remembered.

Addition mechanisms

There are, I think, two significant mechanisms for creating stuff in the atmosphere:

it may be emitted by something on the surface;
it may be created by some process in the atmosphere.

(And again, it may arrive from space, but I'll ignore that.)

How long things persist in the atmosphere

So, now, how long things persist in the atmosphere depends on what they are: the term 'pollution' bundles together things which have radically different characteristics.

Human-generated aerosols (smoke, other aerosols) have relatively short lifetimes in the atmosphere and are not created by processes in the atmosphere, and so will fairly quickly decline in concentration once emission stops.
Aerosols of water – clouds – are created in the atmosphere, from water vapour which will continue to be emitted from the surface, and are also removed from the atmosphere as rain, but these processes balance out over time and so clouds will persist in the atmosphere.  Clouds are not a pollutant of course: I just wanted to add them as another type of aerosol with another lifecycle in the atmosphere.
$\mathrm{NO_x}$ has a relatively short lifetime in the atmosphere as it's not stable: its lifetime in the lower atmosphere is hours, and in the upper is not more than few weeks.  Some $\mathrm{NO_x}$ is created in the atmosphere by lightning, but I think the quantities are rather small compared to the amounts created by human emissions.  So the amount in the atmosphere will decline pretty quickly once emission from the surface stops.
and so on.

The elephant in the room: $\mathrm{CO_2}$

$\mathrm{CO_2}$:

is pretty much chemically stable and so does not decay in the atmosphere (it does undergo processes of being dissolved in water droplets and then evaporating from them, and perhaps others);
is not an aerosol and so does not leave the atmosphere by the mechanisms which affect aerosols, unless it is dissolved in aerosols of water;
is absorbed by several processes on the surface;
is also emitted by several natural processes on the surface.

The things which absorb $\mathrm{CO_2}$ on the surface are, among others (not necessarily in order):

plants, which absorb $\mathrm{CO_2}$ and turn it into plant and oxygen;
the oceans, which dissolve $\mathrm{CO_2}$;
rock weathering;
other things.

The natural (see above definition!) processes which emit $\mathrm{CO_2}$ are (not in order):

plants and animals which respire;
plants (and animals) which die & decay or catch fire, releasing $\mathrm{CO_2}$ back to the atmosphere;
the oceans, which release dissolved $\mathrm{CO_2}$ back to the atmosphere;
vulcanism;
other things.

So in order to know how $\mathrm{CO_2}$ behaves over time we need to understand how the various processes work: how fast is $\mathrm{CO_2}$ cycled through the atmosphere and how fast does the concentration change.

Understanding this is not simple, and it's why people write big climate and earth system models.  But it's possible to give ballpark numbers.

The answer to the first question: 'how long does an individual $\mathrm{CO_2}$ molecule spend in the atmosphere' is 'a few years'.

The answer to the second question: 'how long would it take for $\mathrm{CO_2}$ concentrations to decline to preindustrial levels if fossil-fuel burning stopped, is 'from a few hundred to a few thousand years'.

The reason for the large difference between these numbers is that the natural processes that absorb and emit $\mathrm{CO_2}$ are very close to being in balance.  This is easy to see because we know that the concentration of $\mathrm{CO_2}$ in the atmosphere was not zero before we started burning fossil fuels.

Just to give some figures (these are not meant to be accurate):

plants absorb about $120\,\mathrm{GtC/y}$ through photosynthesis;
plants emit about $60\,\mathrm{GtC/y}$ through respiration;
about $60\,\mathrm{GtC/y}$ is emitted from decay of plant matter;
the oceans absorb about $90\,\mathrm{GtC/y}$;
the oceans emit about $90\,\mathrm{GtC/y}$.

As it stands this is completely balanced.  Well, these figures are approximate, and there are other processes both of absorption and emission.  But it's close to being in balance.

This is why the concentration of $\mathrm{CO_2}$ would fall only rather slowly if fossil-fuel burning stopped.


Do "water-worlds" not have plate tectonics?

can we say that a water-world does not have plate tectonics?

No we can't. Take for example Earth, add in a lot of water to cover all of the continents and you get a water-world with active plate tectonics. The driver for plate tectonics is not whether water exist or not on the surface, but rather the internal heat a planet contains.

Or, the plates of plate tectonics could actually be water ice, as is hypothesised for Jupiter's moon Europa. You have to remember that currently our sample size is one. There is only one planet where we know for sure that there are active plate tectonics, and that is Earth. Ruling out plate tectonics on other planets just because we don't know how it will look like or how it will work is not correct.

That said, water plays an important role in plate tectonics on Earth. Be it modifying the composition of the crust, changing the strength and ductility of the rocks, or some other process.

  then can we also say that these water-worlds cannot harbor life?

No. Again, our sample size is one. There is only one planet we know with life and that is our Earth. Who knows what may be out there? For starters, we don't even know what fired up life here on Earth in the first place. It could be volcanos or hydrothermal vents in the ocean around hot spots, which are (almost) independent of tectonic activity.

On a personal note, we've all seen how astronomy advanced from "are there any other planets out there?" to actually discovering hundreds of them. What was once the exception is now the rule. Who knows, life might actually exist on just about every solar system out there.


Replacing 20% or more of the normal water in ones body with heavy water results is toxic (Kushner 1999). Then again, a number of vitamins are toxic in high doses, but vitamins are essential to human life. Could deuterium in small doses be essential to life? That's exactly what Somlyai et al. argue in their paper (Somlyai 1993).

However, it's a bit premature to start shouting "peak deuterium." We don't even know if ITER will prove to be successful, let alone point the way to commercially successful fusion. Even if it does prove to be successful, the deuterium consumption rate will be tiny. By the time our children's children's ... children would have to shout peak deuterium, we'll have gone on to even bigger and better things (if humanity lives that long).

Kushner, et al. (1999), "Pharmacological uses and perspectives of heavy water and deuterated compounds," Canadian Journal of Physiology and Pharmacology, 77.2:79-88.

Somlyai, et al (1993), "Naturally occurring deuterium is essential for the normal growth rate of cells," FEBS letters, 317.1:1-4.


Where can I find papers on the geology of the Wastach Range in Utah

This report on the stratigraphy is probably a good place to start.

Additonally, searching Google Scholar for Wasatch Range geochronology brings up a number of papers on the geochronology of specific formations if you are interested in that.


Terrestrial Day vs. Venusian Day: Why the Huge Time Difference?

There is no reason why the day length should be the same. From the time of planetary formation, some 4.6 Bn years ago there has been some degree of slowing of day length due to tidal friction, which is much higher on Earth than on Venus, so the original contrast in day length may have been even greater than today.

There are three major reasons for differencial spin rates. Firstly, the initial planetary rotation rate was a function of the net angular momentum of the planetesimals, gas, and miscellaneous debris from that part of the solar nebula from which the planet condensed (in accordance with the conservation of angular momentum). There is no reason to suppose that that the original solar nebula consisted of a nicely ordered, evenly distributed mass/velocity distribution. Rather, there is every reason to think that it was a highly chaotic heterogeneous cloud of matter undergoing gravitational mayhem - probably including large scale gravitational disruption by gas giants much closer to the sun than we see them today. From such chaos one could model almost any distribution of relative rotation speeds amongst the final planets.

Secondly, there is strong evidence that proto-Earth collided with a 'trojan' named 'Theia', about the size of Mars, about 4.3 Bn years ago. This is the 'giant impact hypothesis', which provides a good explanation for Earth having such a large moon. We don't know the relative angular momentum of either proto-planet, their relative motions, or the angle of impact (head on? glancing?), so it is probably impossible to reconstruct the event. However, it is (relatively) easy to envisage how such an impact could radically change the Earth's angular momentum. The spin could have been hugely accelerated or decelerated according to the physics of the impact.

Thirdly, Venus's relative proximity to the sun could have resulted in its undergoing rotational capture, such that eventually one face of Venus will perpetually face the sun. This gravitational locking of Venus is probably the most significant reason for its' long day. As you rightly note, the retrograde spin of Venus is curious. Therefore we may infer that Venus's spin history is more complex than we can account for by simple planetary accretion.


What is the difference between a carbon sink and a carbon reservoir?

The difference is that a carbon sink accumulates carbon, whereas a carbon reservoir has accumulated carbon.

That is to say:

A carbon sink is an ongoing process which is increasing the amount of carbon stored in it.

Whereas although a carbon reservoir might exchange individual carbon-based molecules with other parts of the carbon cycle, as much will go out as goes in, keeping the amount of carbon in the reservoir broadly constant.

Both of these contrast with things such as coal seams and natural gas & crude oil reservoirs that humans have tapped as sources of fuel; and leakages of methane from the ground: these were carbon reservoirs until the amount of carbon in them began depleting (e.g. through mining, well-drilling, or - in the case of methane clathrate leakages - ice melt), at which point they became carbon sources.


What would people drilling through Mount Everest find?

The summit of the mountain is made up of 400 million year old sedimentary rocks laid down long before the uplift 50 million years ago.  These rocks contain marine fossils including Trilobites and Crinoids. If you drilled down from the summit you would then encounter older metamorphic rocks,  the upper parts of which contain traces of fossils, and then in to gneisses and granites.
http://all-geo.org/metageologist/2012/06/the-geology-of-mount-everest/


How to design an experiment to quantify back radiation from atmospheric carbon dioxide?

The thing is, we don´t have any instruments(to my knowledge) to measure the intensity of that radiation. But, we measure the intensity of atmospheric emission from space with satellites, which is seen as the "effective temperature". Logically this is the same as the net radiation downwards. And heat transfer then confirms that no net radiation arrives at the surface. Which is equal to "no radiation at all". Because "net" radiation is the only radiation that can heat anything.

There are lots of people claiming that measurements done with IR sensors and pyrgeometers confirm backradiation. This is not true and it is based on a misunderstanding of the function of the device, as well as misapplication of the stefan-boltzmann equation. Both IR-thermometers and pyrgeometers use the s-b equation  in combination with a thermocouple or thermopile(pyrgeometer). They are both a kind of more advanced and more sensitive thermometers. The thermopile consist of a sensor measuring a gradient across itself indirectly by changes in resistance acting on a current through the thermopile. So, by determining the gradient in the thermopile, it can sense the amount of heat transferred to the surroundings using the s-b equation. When someone claims measurements show "back-radiation", they refer to measurements done with these devices. As most interested people understand, a measurement of heat transfer away from the device, cannot show incoming radiation from a colder atmosphere. If you measure something hotter than the temperature of the thermopile, sure, then you have high accuracy. But a measurement of "back-radiation" from the atmosphere is per definition a measurement of something colder than the device. Because the atmosphere is almost always colder(exception is inversion, but that is not relevant). So any measurement of backradiation made from the surface, is a measurement of nothing. It is simply what the device doesn´t measure coming from the atmosphere. This is what I mean with "misapplication" of the s-b equation. It can not, and should not, be used that way. That is, to add flux densities that are not calculated as "net" transfer.

In regards to your suggested experiment. Unless the gas is hotter than the instruments(if using IR-instruments), you will measure a heat sink, not any backradiation. And, yes, that is what greenhouse gases really are. Heat sinks. The earth emit its heat to the ultimate bottomless heat sink in space, the only observed infinity, and greenhouse gases are added heat sinks along the highway for heat, that leads to 3 Kelvin space.


High resolution global land use projections

While this isn't 10km or less, the CMIP6 dataset is released as of last week. It's now at 0.25degree spatial resolution which is an improvement.


What are some options for online and offline particle tracking in ocean models?

The main difference between online and offline trajectory calculation is that the online is implemented as part of the model, and the trajectories are part of the model output. Offline trajectory calculation is a separate piece of software that takes Eulerian model output fields as input and calculates the trajectories.

The main advantage of online particle tracking is that the displacement of a particle or tracer can be evaluated every time step, no matter how small it is. As a result, you can obtain a true particle trajectory based on what model produces. The disadvantage of the online tracking is that the user needs to know the particle release location and time ahead of running the model. The models listed below (at least) support online Lagrangian trajectory calculation:

HYbrid Coordinate Ocean Model (HYCOM) is a hydrostatic, hybrid-coordinate ocean circulation model that has particle calculation built-in;
MIT General Circulation Model (MITgcm) is a non-hydrostatic circulation model with many physical parameterization options and a single dynamical kernel for both the atmosphere and ocean;
Regional Ocean Modeling System (ROMS) is a hydrostatic, sigma-coordinate (terrain-following) ocean model with many physical parameterization options a large user community.

On the other side, offline particle tracking can only use the Eulerian fields as often as they are output. Thus, there will be an error in the calculated trajectory depending on the frequency of the output. On the other side, the main advantage of offline calculation is that the user can experiment and play around with deployment locations, times, area of coverage etc., because trajectory calculation typically takes much less computational effort than the actual model. There are several options here:

Connectivity Modeling System (CMS) takes gridded NetCDF files as input and produces Lagrangian trajectory output. Can handle fields from various Arakawa-staggered grids, and may produce probabilistic trajectories, diffusivity specified by user (optional). Compatible with at least HYCOM and ROMS output.
Ariane also takes gridded NetCDF files and is compativle with at least HYCOM, ROMS and NEMO models.
TRACMASS seems to be compatible with many circulation models. It also has a Python interface.

All models and tools listed in this answer are freely available for download under different open source licenses.


How do rivers last so long in dry weather?

The rivers are generally fed by water that percolated into the ground, it takes longer for that water to work its way down to the stream so the streams and rivers keep flowing long after the initial rain. https://water.usgs.gov/edu/rivers-contain-groundwater.html


Why are there places where trees don't grow?

A non-conclusive list:

frequent wildfires
not enough water
too much water
bad soil conditions
average temperatures too high or low
not enough sunlight
animals
human intervention
other vegetation is better adapted to local conditions and thus suppress growing trees


How accurate is the law of superposition?

The principle does not apply to all materials on earth as observed by us but is primarily concerned with sediments and rocks that form from sediments. Since sedimentation is a process driven by gravity grains settle one on top of others and there is no possibility to change that without adding additional processes. So from this perspective the principle is 100% in situations where it is applicable.

It is of course not uncommon to find situations where older material overlays younger. In such cases there has been additional forces (natural mind you) in action. It is for example possible for intrusions (magma) to be injected in older solid rocks thus completely changing the age sequence. It is also possible for crustal movement (tectonics) to fold the bedrock and thrust parts of the bedrock to overlay other parts hence creating situations where younger rocks seem to undelie older. It is also possible for sediments to slide or move downslope so that a reverse or at least disturbed age sequence is established. I could continue ad infinitum.

So many possibilities exist to obtain such cases but always with a logical explanation involving post-sedimentary processes. To correctly interprete observations, one has to have gained full understanding of the geological setting and history as well as physical processes. It is not generally wise to look at an outcrop or cut and create a larger scale interpretation without such background knowledge.


How do seismic charges help to investigate the subsurface?

Explosives are just one way we can produce seismic waves in the ground. By placing geophones on the surface, which measure the rate of change of displacement of the surface, we can actually guess where there are boundaries between different rock types in the subsurface. When we detonate our chosen 'seismic wave generator' the geophones begin recording this change in displacement. As the seismic waves propagate and hit boundaries between rocks of different acoustic impedances (resistance to propagation of seismic waves) some of that wave energy will reflect back to the surface and some will be transmitted downward (http://petrowiki.org/Seismic_wave_propagation#Reflection_coefficients). The amplitude and sign (positive/negative) of those recorded wiggles tell us about how big the contrast in acoustic impedance is as well as if acoustic impedance is increasing/decreasing downwards. This allows us to produce a picture of the subsurface where the x-axis is offset of the geophones from the wave source and the y-axis is the time it takes for the wave to travel down and back up as shown in this picture:

However it is never that simple. A lot of processing has to be done to make sure our initial image is the most accurate picture of the subsurface we can make and even then there is still uncertainty. It must also be stressed that we don't actually know about the properties of the rocks themselves just that boundaries exist between these rocks. If we want to estimate that we can use processes such as seismic inversion.


There are two key intermittent mid latitude circulation patterns during boreal winter.

One is blocking flows, leading to the formation of blocking anticyclones.  One can gauge the location of blocking events through the CPC blocking index.

The other one is sudden stratospheric warming, where the winds cause a disturbance such that the temperature in the stratosphere (the layer above the typical weather layer, the troposphere) warms significantly.  To view this one needs to look at the temperature change over the poles, typically by looking at the 10 hPa isobaric surface. If the temperature change is around 50 to 70 degrees Kelvin over an area of synoptic scale and the temperature change is rapid, over a period of 3-4 days, then you have the possibility the weather can be impacted by a sudden stratospheric warming event.

The possibility is that a sudden stratospheric warming in January 2019 could cause the stratospheric polar vortex to split. Based on the peer reviewed reference The Influence of Stratospheric Vortex Displacements and Splits on Surface Climate it is actually the troposphere that causes polar stratospheric variability through vertically propagating Rossby waves. The math behind that is quite complex but it also feeds off linear theory (which can be seen in the quasi-geostrophic Potential Vorticity equation). Some of these vertically propagating waves can travel all the way up into the mesosphere. These lecture notes on Rossby waves mention that Rossby waves cannot propagate vertically if the mean zonal winds are easterly or if they are westerly and exceed a certain speed. It is only the wintertime atmosphere that permits Rossby waves to reach the stratosphere and deposit energy and hence sudden stratospheric warmings are only observed after boreal fall.

In the northern hemisphere most vertically propagating Rossby waves arise due to the topography.  In the southern hemisphere the sudden stratospheric warmings are a rarity due to lack of such topographical features. The last sudden stratospheric warming over the southern hemisphere was in 2002.

The resulting stratospheric anomalies can in return influence surface climate but the mechanism on how exactly this occurs is the still the matter of scientific research.  One of the theories that is currently popular is the wave mean flow interactions. This can be easily summarized as concerning how planetary scale Rossby waves influence the circulating zonal flows around a planet.  The other main theory is wave reflections at the tropopause.

So what is the net result of either of the above two possibilities? Either way they affect mid-latitude storms. Storms could either become more intense, shift equatorward, or there could be extremely cold air advection spells as the stratospheric air gets mixed into the troposheric air.

As to the rarity of polar vortex splits - they are coupled to those sudden stratospheric warmings. If you look towards the climatology of SSWs, observations show that they occur more during El Niños and La Niñas than during neutral conditions. Sudden stratospheric warmings happen almost every other year in the NH. However sometimes the polar vortex isn't split during these events but is merely pushed equatorward.

The long term effect a polar vortex split could be extended spells of extremely cold weather in the affected areas, and when the vortex reforms on into summer it would be shrunk in size from the dispersed energy giving rise to greater easterly wind circulation near the poles.

UPDATE

Now that the reanalysis data is available from January 2019 I want to add some visuals for the Dec-2018/Jan 2019 polar vortex split and ongoing cold wave.

The OP's link, plus this SlashGear article on the polar vortex split provide GEFS and GFS forecast data, pointing to a three-way split of the polar vortex. I went through reanalysis data from the period of Dec 18th 2018 through Jan 30th 2019 and there appears to be two separate candidate dates for a three-way split of the stratospheric polar vortex; it really depends on whether one considers the small vortex over the North Pacific as one of the split vortices or not on Jan 5th 2019. The 5th January event is the one that most closely resembles that GFS forecast data. In saying this, the reanalysis data is averaged over a full day as opposed to the single point in time of the GFS data. In the geopotential height anomaly there is a clear three way split but one must remember that the anomalies are calculated vis-a-vis the climatological period 1981-2010. Either way this will require more detailed research before the three-way split is confirmed or not.

Finally from the reanalysis data it appears that, in contrast to the 2018 event, this year's event points to significant instability in the dynamics of the polar vortex. There are clear suggestions that the polar vortex is breaking and reforming again over short time scales, which is interesting.


Relationship between rainwater and solar radiation

Any relationship or correlation? That is quite a broad standard. Invoking Tobler's first law of geography, there is a relationship. I would question if there is such a thing universally, but there are some instances that we can see an overlap. For example, many deserts receive plenty of sunlight, but observe little rain.
One of the first things that comes to mind are instances where these overlap. A plant needs both water and radiation to grow.
Another thing that comes to mind is the investigation of land-atmosphere coupling metrics. There are plenty of metrics that try a variety of methods capturing a plethora of different dynamics. These are indirectly associated with sunshine, as the surface fluxes are driven by solar radiation.
As far as finding a specific spot for self-sufficient drinking water, I am afraid that any relationship you get will not be one that will yield such a desired result. If you want an environmentally friendly, generally reliable way of attaining water, try well water.


What is a temperature inversion and can it trap smog/pollution?

Normally, temperature broadly decreases with altitude, and convection is effective: locally warmer air will rise, and cooler air will fall. A temperature inversion is where the air temperature rises with altitude. This means that convection is less effective because the air above is already warmer, and so there is less mixing of air between altitudes.

Since pollution is generally produced at ground level, temperature inversions can trap the pollution (e.g. smog) at ground level.


Overbank flows means flows that are greater than the channel can handle. Thus the water flow goes over the (river/stream) banks and onto the flood plain.

Bankfull flow would be the maximum water flow that the channel could contain.

Note that flow in the channel isn't necessarily the bankfull flow. Of course if there is overbank flow then there must be bankfull flow.

total flow = Flow in channel + Overbank flow


Is there more water in solid form than in liquid form on earth?

Clearly you are referring to water locked up in hydrous minerals. The short answer is no, not much water in the Earth at all compared to the surface. The hotter it gets the more hydrous minerals tend to dehydrate, so there are only minuscule traces of water at great depth. I suggest you calculate a rough water balance of water carried into subduction zones = length of subduction zone x thickness x sediment porosity (under pressure) x average subduction rate. This should be compared with estimates of volcanic emission of water vapour (both to the atmosphere and submarine - more difficult to estimate). I'm guessing these should be more or less in equilibrium. The water volume involved is trivial compared to the water on the oceans.


Are 60C heat waves predicted by 5C of global heating? (The worst consequence of global heating)

Neither an answer, just common sense.

Not sure if anybody can give exact numbers for temperatures of future heat waves in their projections. Predictions are difficult, especially those regarding the future. But there is consensus and now observation that heatwaves become more frequent and hotter not only on land. One could perform a search for publications that deal with the impact of land heatwaves, e.g. on agriculture (wheat for example), desertification, loss of habitable space, flooding, loss of resources like potable water, etc. There is a lot of published work around.

We went past the 1°C warming compared to pre industrial levels in 2015, after [https://www.ncdc.noaa.gov/cag/global/time-series] and many publications. Current estimations range between 0.9 and 1.6°C for 2019. Several islands have been devastated in the past years, damage still not totally repaired. Jakarta is drowning, catastrophic fires in California, Australia and elsewhere, fed by drought, heat and mismanagement, cost lives and property.

The effect of past and current heatwaves on the health of the population is pretty well visible, western European countrie's and the US health departments have published their estimations of fatalities attributed to heat.


How to understand the sentence below about rapid or fast exchange between vapour and droplet?

The wording is not clear, but here is what I understand:

In case of extremely rapid exchange of molecules between the droplet and the surrounding vapour, the droplet gets the same O18 abundance as the vapour because they reach equilibrium.

In case of extremely slow exchange of molecules between the droplet and the surrounding vapour, the droplet keeps the O18 abundance that the vapour had where the droplet was formed. This is a different location (lower in the front, as shown by figure 2), so the abundance can also be different.


Why is continental crust less dense than oceanic?

Thickness has nothing to do with density. The density is how much a given volume weighs. If a block of 1m × 1m × 1m weighs 60kg, and another block the same size weighs 100kg, then the second block is more dense than the other.

So if the material that makes up the continental crust is less dense, then the continental crust will be less dense.

This almost sounds like a homework question, so I will leave references and such for now, but finding densities and compositions of these varying crusts is not too difficult.


I am going to take an educated guess here because it is not possible(AFAIK) to accurately predict with any known skill what several decades into the future would be like.
Given that premise the largest hurricane in the future could be the size of the tropical extent of the Pacific Ocean or the Atlantic Ocean(wherever that begins and ends). Here I am only considering the Northern(or Southern) tropical extent of the Pacific or Atlantic Ocean because as we know a tropical cyclone cannot cross the equator as explained in this in depth answer Impossible or improbable? Hurricane crossing the equator. The thought process behind this idea is that hurricanes(tropical cyclones) dissipate on coming contact with land. Hence the maximum area of the largest cyclone in the future would  have to be the ocean body maximum tropical extent(typically sea surface temperature (SST) greater than 27 degrees centigrade). Just in case if people are wondering why just the tropical extent and why not more than that ? It is because once you enter into mid latitude regions frontal processes could kick in(cold core cyclones-as an example -Can a tropical cyclone form in mid latitude oceanic waters?)
So if the tropical extent of the biggest oceans increases in the future one can imagine a very large possibly synoptic scale tropical cyclone.
Here I am excluding the North Indian Ocean basin because it does not have the surface area to compete with the North Pacific or North Atlantic
Secondly from this popular science article -How strong can a Hurricane get? and this one Are Category 6 Hurricanes coming soon ?

By the end of the 21st century, human-caused global warming will likely increase hurricane intensity, on average, by 2 to 11 percent, according to a review by NOAA's Geophysical Fluid Dynamics Laboratory, revised on Aug. 30, 2017.

followed by

But physics dictates there must be a limit. Based on ocean and atmospheric conditions on Earth nowadays, the estimated maximum potential for hurricanes is about 190 mph (305 km/h), according to a 1998 calculation by Kerry Emanuel, a climatologist at the Massachusetts Institute of Technology.
This upper limit is not absolute, however. It can change due to changes in climate. Scientists predict that as global warming continues, the maximum potential hurricane intensity will go up. They disagree, however, on what the increase will be.

So theoretically a Category 6 Hurricane could have speeds of more than 200 mph.But scientists disagree on these calculations and i am going to leave it at that.


Why can't radar's decibel scale be used to determine the intensity of snowfall?

Snow, unlike rain, has holes as well as different refractive properties. This allows the radar beam to penetrate and reflect the beam differently than an ordinarily oblate rain drop.


Caveat: I'm answering this in a popular context. There may be more technical definitions, which I'd be interested in hearing about.

It seems to be generally accepted that continents are not, themselves, islands. This is a common confusion in pub quiz questions, where people argue over whether the largest island in the world is Greenland, Australia, or (if somebody especially pedantic is around) the combined landmass of Europe, Asia and Africa.

So the question comes down to "what is a continent"? It's more of a political / historical / geographical unit than a topological one. If continents were demarcated by coastlines, then Europe, Africa and Asia would all be one. Additionally, many small mid-ocean islands, which are not on continental shelves, would end up being continents.
It's tempting to think of continents as relating to tectonic plates, but even if we disregard mid-continent faults and "complicated" areas, Europe and Asia are hard to separate.... and the 6 continents as currently thought of were pretty much set before plate tectonics was advanced as a theory. Wikipedia has an interesting article on historic boundaries between continents; the one between Europe and Asia is especially ambiguous.

I'm not aware of any definition of "subcontinent", and have never heard this term used for anything other than the area around India, so I suspect this is also a political and historical term.

So to answer the question: No, there is not a size-based distinction between islands and continents, although the smallest continent is indeed bigger than the largest island. The definition of an island would seem to be "a landmass surrounded by water that is not thought of as a continent".

As for "islet", again, I'm not aware of any formal definition. However, the UN Convention on the Law of the Sea does distinguish between islands and "rocks", where the latter are islets that are too small to be habitable. This is an important definition, because unlike islands, rocks are not considered when defining a nation's exclusive economic zone (the area in which they may control who fishes, drills for oil, and so forth).


How did the terms "acidic" and "basic" come to be associated with $SiO_2$ in igneous rocks?

The idea came from the theory that silicic acid was the chief form of silicon occurring in rocks.  Early attempts to classify minerals, placed some mineral specimens in groups based acid-base reactions and the hypothetical acid that mineral was derived.  Sulfates, phosphates, nitrates , and tungstates etc.

This thinking was the result of 19th century chemistry research which attempted to explain chemical reactions in terms of  acid-base reactions.

Much of this terminology is still in use today even though it is considered archaic now.


How to calculate water vapor flux divergence from temperature, relative humidity, u wind and v wind?

The formula for moisture flux is $$q\vec{V} $$
where $q$ is the water vapor mixing ratio, which can be found using mixhum_ptr and $\vec{V}$ is the velocity.

Therefore the divergence of the moisture flux must be
$$\nabla{\dot{}q\vec{V}}=\frac{\partial(qu)}{\partial x}+\frac{\partial(qv)}{\partial y}+\frac{\partial(qw)}{\partial z} $$
$$\approx\frac{\delta(qu)}{\delta x}+\frac{\delta(qv)}{\delta y}+\frac{\delta(qw)}{\delta z}$$

which is computable if you have gridded data.

For example, you could compute this by setting
$$qu=q\ast u$$ $$qv=q\ast v$$ $$qfluxDiv=uv2dv\_cfd(qu,qv,lat,lon,opt) $$
Use uv2dv_cfd per http://www.ncl.ucar.edu/Document/Functions/Built-in/uv2dv_cfd.shtml

Note: If you wanted the turbulent moisture flux, you would need to subtract $\nabla{\dot{}\bar{\vec{V}}\bar{q}}$ from your answer.


What are the risks of developing geoengineering?

We don't know, and that's why we have to develop it.
that's the thing about undeveloped sciences we don't know what many of the risks are, Its a case of knowing what we don't know. Which is one big reason to develop it, so we don't cause harm accidentally.
Lets be clear we already are geoengineering right now, by driving cars, changing the landscape, polluting the air,  we are just doing it blind. We have to research things to understand the risks, and geoengineering has barely be scratched.


I would suggest you contact your local government agricultural authority.
It looks like the barley crop might be infected with a pathogen, such as a fungus.
It could be a form of barley rust.
Different regions of the world have different forms of rust.
Your local agricultural authority should be notified in case the outbreak poses a bio security risk in your region.


Why do manganese nodules have different constitution than sea water?

Many reasons: First, the sea water does not have a uniform composition of dissolved metals. Second, if the nodule, either now or in the past, has been in proximity to an oceanic hydrothermal vent ('black smoker') then the source metal concentrations will have been dramatically different. Third, at thermodynamic equilibrium, each metal will have a different liquid-solid phase partition coefficient, and even slow precipitation isn't necessarily at thermodynamic equilibrium. Fourth, the Mn-nodule mineralogy may contain some proportion of clay with different adsorption capacities for different metals. Fifth, These nodules are lying on the sea bed, so it isn't just pure sea water that we are dealing with. There is also slowly circulating pore water from the underlying sediments. This pore water can have a huge range of composition derived from water-rock interaction, depending upon temperature-pressure history, pH/Eh, rock composition, depth of circulation and history of water-rock interaction. Finally, it is more than likely that microbial mediation is involved in metal oxide deposition at the liquid-solid interface (in which case all bets are off in respect of thermodynamic equilibrium), and almost anything can happen, depending upon microbial species, metabolism and micro-ecology.


What is the most optimal latitude on Earth for the generation of extreme maximum temperatures?

The places that get the hottest temperatures are close to the equator but not necessarily on the equator. They will be low lying places, perhaps below sea level, and 'enjoying' a continental climate. For the record books, they will also need to be places where a climatologist passes through at the right time to measure it. I see you mention some record temperatures in your question, but I don't remember off hand what the absolute world record temperature is. It won't be far short of 55 C, but what amazes me is how the people who measured such temperatures survived to tell the tale. The atmosphere must have been very dry. From the point of view of human wellbeing, in high humidity temperatures well short of world record don't feel well short, and are almost as dangerous.


The oldest undisputed fossil are Stromatolites, bacterial mats, the oldest of which are dated ay 3.7 billion years ago. The key term here is undisputed, there are other possible fossils but it is very hard to have certainty with chemical or cellular fossils. The oldest uncertain fossils trace back to 4.28 billion years and are possible bacteria trapped in hydrothermal vent products.

The oldest fossil of a creature with a brain is weird. it is actually several creatures from Ediacaran biota. These are also some of the oldest multicellular life fossils, lacking any hard parts fossilization of early small animals is incredibly rare event even considering how rare fossilization already is. There are several bilaterally symmetrical animals capable of movement, this combined with the fact they are more than two cells thick means they almost certainly had a brain.

Kimberella and Spriggina and their relatives are both almost certainly mobile, with some form of nervous system based on phylogenetic bracketing, others are also likely since the ancestor of chordates may in there somewhere. We know there were moving creatures from the ediacara because we actually have trace fossils that are consistent with a muscular moving organism like anemone.


What do physical oceanography grad schools look for?

Most of the physical oceanography students I know studied mechanical engineering, physics or mathematics in undergrad. Strong physics and mathematical skills are very important. Programming is also a plus. Having a few earth sciences courses is good, but the physics and math is much more important, so I think you will be in good shape.

However, beyond the basic background, clear ability to do research is very important in PhD admissions. Even if the applicant doesn't have any research experience, there are ways he/she can show that potential. A clear statement of purpose that outlines and contextualizes the problems the student wants to address in graduate school will catch the eye of any professor looking for students. There many students who have posters at AGU, GSA ect, however, the truth of the matter is that most undergraduates with research experience entering graduate school aren't ready to hit the ground running anyway. Professors know that, as they have had students before.

For courses, I would say skip the environmental modeling course unless it is directly related to what you want to research. Take the remote sensing, and instead of environmental modeling, take a full on numerical modeling course. A rigorous undergraduate level (or if you can stomach it, graduate level) will give you a very strong foundation for whatever simulations you may or may not to run during your career as scientist, even if you start out as a purely observational scientist. Fluid Mechanics is also a no brainer if you still have time.

Finally, the oceanography researchers at LDEO (columbia university) are top notch. So are the ones at University of Washington, Hawaii, and Rhode Island.

Good luck on your applications, you have a lot of time to decide what you want to do (since your junior year just started I'm assuming).

The best advice I can give you is look at what researchers are doing on their websites and try and read a few of their papers. If you know any professors with these same interests, ask them what you don't understand.  Earth Sciences is much different than math (I came from pure physics), spend some time trying understand what an oceanographer does. If you can figure that out, you will be more than prepared to reflect that in your statement of purpose and you will be a stellar candidate for graduate school.


Looks like massive (as in the individual crystals have grown into each other) Quartz, the different colours are due to minerals either dissolved into the crystal structure, those are the dark areas, or simply staining the surface as with the rusty red/orange sections. It could be Calcite or Salt, the first will react with Vinegar and second will dissolved in hot water but both are rather fragile and it would be easy to break off small samples.


Introductory course on interpreting GOES-R satellite images?

There are numerous short modules offered by UCAR's COMET/METED website: https://www.meted.ucar.edu/training_detail.php
Modules specific to GOES-R include (but aren't limited to):

GOES-R/JPSS test cases for convection initiation and wildfires.
Advanced Baseline imager
A satellite foundational course

There are 19 courses with GOES-R in the title.


Evidence for "earthquake storm" at the end of the Bronze Age

Nur & Cline (2000) constructed a map of sites destroyed in the Aegean and Eastern Mediterranean region during the years 1225–1175 BCE. They also provided a map of earthquakes of magnitude above 6.5 that were measured during the XX century. They claimed that "virtually all of these Late Bronze Age sites lie within the affected (“high-shaking”) areas". They also showed evidence of earthquake damage in many of the main cities of the area and point out that:

  While such a ‘‘storm’’ is unlikely to have been the sole cause
  of the end of the Late Bronze Age in the Aegean and the Eastern Mediterranean, it may have interacted with the other forces at work in these areas c. 1200 BCE

The idea of an "earthquake storm" has been around at least since 1970. Ambraseys (1970) describe multiple "earthquake sequences" lasting around 40-50 years with "quiet periods of more than a century in a nearby fault system (the Anatolian fault zone).

In a study preceding the Nur & Cline work, Nur (1998) provided a possible explanation to connect earthquake damage with civilization collapse:

  The earthquake in this ca. 50 year long storm could have render many of the urban centers militarily vulnerable, thus inviting attacks not by powerful, distant Sea People, but by opportunistic indigenous or neighboring populations. These attack might have led in turn to the political and social collapse of the centres, followed by a dark age of recovery and rebuilding often lasting a few hundred years.

They also provide an example from the Old Testament: Jericho, that was attack by invaders after the city walls collapse.

A simple explanation of the potential set of events is given in this video.


The dynamics of the tides are quite complex. The main idea is that gravity from the Moon and the Sun affect water (and everything else) on Earth. The issue is that there are several motions that alter the distance between the 3 systems and those motions cause interactions between the different frequencies involved. The Equilibrium Theory of Tides separates the different effects into a set of constituents by conducting a harmonic analysis. The relevant periods are:

the lunar day (period of lunar rotation), 24.84 mean solar hours.
the sidereal month (period of lunar declination), 27.32 mean solar days.
the tropical year (period of solar declination), 365.24 mean solar days.
the period of the lunar perigee, 8.85 years (1 year = 365.2421988 days).
the period of the lunar node, 18.61 years.
the period of the solar perihelion, 20940 years.

The explanation of each constituent can be rather complex (some examples in this other answer). The different amplitudes in a day and the spring-neap cycle are related to the combination of the main lunar and solar effects.

The differences in high/low tide from month to month are related to the next two main frequencies of oscillation. Mainly, the variations in Earth-Sun distance associated occurring in a period of tropical year. The lunar distance also contributes to these differences, but its cycle is much longer (~9 years). Also, the spring-neap cycle (with a frequency of half a lunar month ~13.5 days) will occur at different times of the month and can lead to differences in tidal amplitude if you compare the tides measured the same day of consecutive months.

(Source www.niwa.co.nz)


Which markers could suggest that there was extinct or extant life on Mars?

One of the next big missions to Mars, named Mars 2020 is planned to depart from Earth to Mars during late July 2020. This mission involve a very capable rover, like Curiosity on steroids.

From the mission site:

  The mission takes the next step by not only seeking signs of habitable conditions on Mars in the ancient past, but also searching for signs of past microbial life itself.

This mean that there is two important objective:

to find extinct life forms, such as assuming there was conditions a long time ago permitting lifeforms to exist on Mars, likely 3-3.5 Billion years from now or so, in other words, fossils. Why 3-3.5 Gy ago? This was during Hesperian geological epoch when water was likely a major agent in forming channels lakes and rivers, thus with atmospheric and ground conditions possibly permitting the existence of life back then.
to find extant life forms such as bacteria that are existing presently on Mars surface or near surface.

One component of the mission is to sample rocks that are likely lifebearing, analyze and store for a later pickup by a further mission. Lifebearing rocks in that case may be found as old lake beds, for example iron rich lacustrine mudstone.

Lacustrine mudstone is obviously originating from depositing fine sediments over a lake floor, a stable environment through a long time, as shown by layers like this (pictured by Curiosity's MastCam in 2014). And iron rich is important as this chemical arrangement is favoring and helping the preservation of microbial lifeforms.

Source: https://www.nasa.gov/image-feature/jezero-crater-mars-2020s-landing-site

As can be seen in the picture, the big circle (as a crater) in the center of the delta is named the Jezero crater and is the target landing site for Mars 2020. This delta was formed due to water flowing in a lake; clay rich deposited were detected in the area. The crater is exposing deeper (early) layers in the delta, making this an ideal exploration site to look for extinct or extinct life.


Fine particulate matter - Why the lack of attention? What can be done to tackle it?

There has been some considerable attention, it is not that factor that is hampering more coherent action, it is a lack of full understanding of the fine particulate matter itself - allow me to explain.

A lot of the reason why there has only been largely piecemeal approaches to combat Fine Particulate Matter, globally speaking, is due to the incomplete understanding of the aerosols and their dynamics themselves.

Having said that, there are different strategies to combat fine particulate matter (FPM). But, first, a definition - the United Nations Environment Program (UNEP) page Pollutants: Particulate matter (PM) states:

  PM 2.5 refers to particles with a diameter of less than 2.5 microns. These are usually called fine particles and contain secondary aerosols, combustion particles and re-condensed organic metallic vapour, and acid components. Fine particles can reach all the way down to the alveoli in the lungs.

The inclusion of secondary aerosols, combustion particles (e.g. soot) and recondensed organo-metallic vapour can and does complicate attempts to mitigate the effects once released and would also complicate attempts to prevent the release.

It could be argued that the ultrafine fraction at 0.1 microns and less could be included under the FPM umbrella; however, as stated on the UNEP page, these are still the focus of extensive research.

There are several documents calling for the control and providing practical strategies by governmental organisations, one such document is the US EPA's Controlling
Fine Particulate Matter
Under the Clean Air Act:
A Menu of Options (2006), in which it is acknowledged that

  The chemistry and physics of PM2.5 formation in the
  atmosphere is incompletely understood.

also, in a practical sense,

  In a perfect
  world, control-efficiency and cost-effectiveness data would
  be at hand; however, it is not consistently available.

and also in a scientific - practical sense:

  there are important distinctions
  between filterable and condensable PM2.5. Further, some
  methods used to measure PM emissions reflect only the
  filterable components and, to exacerbate the problem, the
  filterable components vary depending on the test method
  used.

The first step in any attempts to mitigate the FPM content in the air is to monitor the sources, flow, composition etc of the particles.  From the EPA document:

  The importance of determining source apportionment
  for ambient PM2.5 in a specific area cannot be overstated;
  developing a cost-effective approach to controlling PM2.5
  emissions sources requires an understanding of the relative
  contribution from local and regional sources. Adequate
  monitoring data are needed to provide insight into the
  composition of ambient PM2.5 in a given area.

A British document Fine Particulate Matter
(PM2.5) in the United
Kingdom (2012), states the reason why action is not happening fast enough reasonably well, with

  The science underpinning the knowledge of PM2.5 is rapidly evolving and
  remains uncertain in many areas. There is a need for rapid translation into the
  policy arena of the newest results and understanding.

The uncertainty due to the varying compositions, which in turn affect how the particles move, how they interact with the surrounding environment suggests that 1 method would not be sufficient, and that more localised methods of control are necessary.

As you suggested, the importance of understanding FPM can not be understated, in epidemiological research Reduction in Fine Particulate Air Pollution
and Mortality
Extended Follow-up of the Harvard Six Cities Study (Laden et al. 2006), there have been found to be a drop in mortality corresponding to a drop in FPM concentrations.


Where can I download recent precipitation data for Cape Town

It really depends on what you're looking for and what data formats you want to use. If you're looking for single location direct readings from rain gauges, you might have much better luck contacting the South Africa Weather Service (though this might not be free and is typically not 'Open' in the strictest sense of the word).

Some alternatives to that really depend on what you want (gauges, vs. radar estimates vs. homogenized estimates vs. composite products), the granularity (monthly, daily, hourly; observations or normalized climatologies), the spatial resolution (point locations, grids), and the format (Spreadsheets, GRIB, CF-compliant NetCDF, etc.). It's worth also noting that radar detection of precipitation didn't really become an employed standard until the 1980's (ref.)

For a few options that are open, I would suggest looking over what's available through the NSF's National Center for Atmospheric Research . The CMAP: CPC Merged Analysis of Precipitation or the
GPCP (Monthly): Global Precipitation Climatology Project might work for you.


Have cosmic ray muons or solar neutrinos been used to probe inside the Earth?

In November 2008 neutrino tomography was used to measure Earth's mass. A paper was published in journal Nature. The data was captured by the South Pole’s IceCube Neutrino Observatory.

In November 2013 IceCube announced it had discovered 28 neutrinos that likely originated outside the Solar System.

  The neutrinos that the IceCube detector had “caught” came from different angles because they probed different layers of Earth. By measuring how many neutrinos came from different angles, the scientific team was able to measure the densities of various Earth’s segments, and from that – the total mass of Earth.

  The neutrino tomography confirmed the traditional measurements on Earth’s mass, based on gravitational calculations and seismological data. That is especially interesting because neutrino tomography is a conceptually different and independent method – it doesn’t rely on gravity, but purely on weak interactions and the nucleon masses.

  While nothing new was discovered, the fact that a new technique has proven the old calculation right is exciting in its own terms.

Also, from the University of Barcelona.

In 2006 there was a proposal with Harvard University to establish a network of ten detectors to enable tomography of the Earth via antineutrinos.

Not related to the question, but interesting. CERN has a proposal to detect nuclear contraband using cosmic ray muon tomography.


How much do anthropogenic carbon aerosols (soot) affect the atmospheric radiation budget?

For the purposes of the answer, anthropogenic carbon sources, will be referred to as BC (black carbon).

The effects of BC on atmospheric radiative forcing has come under considerable scrutiny in the past few years, several studies have sought to determine exactly the effect of this aerosol has on the Earth's radiation budget.  A major study was performed by Bond et al. (2013), in the article Bounding the role of black carbon in the climate system: A scientific assessment.

A summary of the emissions and effects are shown in the image below:

Caption: Schematic overview of the primary black-carbon emission sources and the processes that control the distribution of black carbon in the atmosphere and determine its role in the climate system. (Bond et al. 2013)

Their findings was that the total direct forcing of BC, independent of co-emitted aerosol species and including all sources (direct emissions, pre-industrial background, cryosphere and clouds) is +1.1 Wm-2 with an uncertainty range of +0.08 Wm-2 to +2.1 Wm-2.

This places BC itself as the 2nd most important anthropogenic emission, behind $\ce{CO2}$.

However, when the total radiative effects of BC with co-emitted aerosols, including organic carbon sources are taken into consideration, there is a slight cooling effect, with the total direct radiative forcing of -0.06 Wm-2, with a greater uncertainty range of -1.45 Wm-2 to +1.29 Wm-2.

Bond et al. 2013.

A major source for the uncertainties is described by Bond et al. (2013) as being due to a lack of knowledge of how black carbon and co-emitted species interact with clouds.

In summary, from the research that Bond et al. (2013) performed, the presence of black carbon itself causes a significant positive radiative forcing, but when considered with its co-emitted aerosols, there is a slight negative radiative forcing.  However, the uncertainties calculated demonstrate that there are still mechanisms that are not completely understood.

Image permissions (from the linked article): This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.


Apparently there is no relation of earthquakes with the weather. But in a book, "Earthquakes- mitigation by Tatsch" there are several precursors associated with ponding earthquakes. One is unusual weather. Some of these precursors are pre- and some post-earthquakes. Your cited earthquake may have some relation with it.


The WRF Forum here describes some testing using a Mac, and they report success with 2 setups:

Mac 64-bit running OSX, with Intel chips, g95 gcc version 4.0.3 (g95 0.92!)

Mac 64-bit running OSX, with Intel chips, PGI pgf90 10.3

There is also some additional information on installing ARWpost on a Mac found on the WRF Forum.

Separately, there is a blog dedicated to your question here and instructions on github here.  Also, if you see the tutorial here, you can see a method that requires you to install Xcode.


These are mammatus clouds. The signify instability (via negative buoyancy, convective mixing, entrainment or other sources) at the cloud base which causes the bulbous udder-like structure. As in your case they can often be observed in association with strong convection.


Which are the points on Earth that receive the least solar radiation on average?

On an average those would be the poles. As you correctly pointed out, due to the tilt of the Earth's axis, there are large areas that receive very little and sometimes no sunlight at all and those change throughout the year. But on an average, poles are the ones that get the least amount of solar radiation.

For example, see this paper and in particular have a look at figures 2.6 and 2.7. The last of the two figures, which I will link here shows the graph of annual mean insolation as a function of latitude.

Here it's obvious that poles do receive the least amount of radiation on an average. But this is the idealized case, i.e. insolation at the top of atmosphere.

On the other hand, if you do take prevailing atmospheric conditions into account then it's a competition between the area between Spitzbergen and Iceland in the North and areas just off the coast of Antarctica in the South. Taken from Wikipedia article on Solar Irradiance the top picture shows top of the atmosphere insolation and the bottom one - ground-level insolation.


Is "Carbon Neutral" (roughly) 5 Gt CO₂ equivalent?

As Camilo mentioned in the comments, “carbon neutral” in this context means zero net carbon emissions.  This is the gross anthropogenic carbon emissions (fossil fuel burning and land use change) minus the carbon absorbed through managed practices.  That distinction is important; you don’t include the carbon absorbed by the ocean and land through natural processes to offset gross emissions in the calculation.
Since 2010, the UN Environment Programme has published an “Emissions Gap” report each year that includes some relevant emissions numbers:

In 2017 greenhouse gas (GHG) emissions - excluding emissions from land-use change - reached a record 49.2 GtCO2e... Emissions from land-use change... added another 4.2 GtCO2, bringing the total to 53.5 GtCO2e.
Source: UNEP Emissions Gap Report 2018

The following is a nice schematic of various negative emission technologies (NETs) that could be used as mitigation in the overall budget:

Source: Smith et al (2016) “Biophysical and economic limits to negative CO2 emissions”, https://www.nature.com/articles/nclimate2870

Carbon capture and storage (CCS) is done at the point of burning fossil fuels, so reduces gross fossil emissions. Panel (g) is called LULUCF (Land Use, Land Use Change and Forestry) in the Emissions Gap reports and AFOLU (Agriculture, Forestry and Other Land Use) in the IPCC 1.5 Special Report, and that is effectively the +4.2 GtCO2e/year quoted above.  The idea is that in the future land management will have to change to turn managed land from a net source to a net sink of GHGs.  As for Bio-energy Carbon Capture Systems (BECCS), the current levels are about zero, although there are a dozen or so demonstrator projects totalling about 0.001 GtCO2/year.  So at the moment it barely makes a dent in the overall budget, but mitigation scenarios require it rising to an order of 10 GtCO2/year by 2050:

The energy production from the use of BECCS over time in a range of mitigation scenarios.
Source: van Vuuren et al (2018) “Alternative pathways to the 1.5 °C target reduce the need for negative emission technologies”, https://www.nature.com/articles/s41558-018-0119-8

The IPCC special report also has a nice schematic of how NETs contribute to emissions scenarios.  Although there's no timescale on the schematic, most of the actual scenarios don't show any notable BECCS until 2030.

Figure 2.5 | Evolution and break down of global anthropogenic CO2 emissions until 2100
Source: Rogelj et al (2018) "Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development", Chapter 2 of the IPCC Special Report on Global Warming of 1.5°C.


How much of all current energy on earth arrived as sunlight vs. as kinetic energy during formation?

We can try to compare sunlight energy arriving from the Sun and geothermic energy coming from the Earth's interior.
The Earth gets about 340 W/m2 from the Sun(1) while the average geothermic flux is about 0.1 W/m2.(2) Therefore, the current energy of sunlight is way larger than that from kinetic energy during Earth formation.
Additionally, it should be noted that a large part of geothermic energy doesn't come from Earth cooling by getting rid of its formation heat but from radioactive decay, making the comparison with sunlight even more one sided.


Does the meridional overturning circulation slow down the temperature increase from global warming?

The short answer is 'yes'. Earth's response to climate change is closely coupled to the deep ocean's uptake of heat and $\ce{CO2}$; the ocean is by far the biggest sink for excess heat (~90% of the excess heat absorbed by the planet goes into the ocean, the rest largely goes towards melting ice sheets/glaciers).
The ocean is also a major sink for carbon.

How effective the ocean is at absorbing heat/$\ce{CO2}$ is closely tied to rates of deep water formation, that is the densification of near surface ocean water by surface fluxes like cooling and evaporation, which then sinks and doesn't come back to the surface for centuries or even millennia. The major deep water formation regions are the Southern Ocean and the North Atlantic. The sinking of North Atlantic Deep Water (NADW) is the northern part of the 'Atlantic Conveyor' (the term sometimes colloquially used to describe the AMOC).

A slowdown in the AMOC, therefore, wouldn't just impact regional climates in N. America and Western Europe, but would also reduce the deep ocean's uptake of heat and $\ce{CO2}$, and by consequence cause a greater increase in surface temperatures.


What is the (average) velocity of ocean currents?

This is not meant to be a comprehensive answer:

Sometimes the easiest way to calculate the velocity of an ocean current is to take the published transport of the current and divide by the total depth of the current.

For instance, for the Agulhas Current, you can take Figure 2 from Casal et al. (2009) (below) and extract the velocities based on the depth of each area. Also in their Figure 6, there are several vertical sections of velocity across the current.

Also, you can obtain vertical sections of velocity for the same current (Agulhas) in earlier publications: Bryden et al. 2005 (Figure 8 and 9). Or in newer publications: Beal & Elipot (2016).

The main issue is that you will need to do a bit of digging around for each of the currents you list.


What is a Rotating Shadowband Radiometer, and how does it work?

A rotating band shadow meter will give you the diffuse radiance as well as direct radiance.  When the band is in the lower location the sensor will measure all the radiance from the sun both direct and indirect.  when the band is raised it blocks the direct sun into the sensor giving an indirect radiance measurement.  The total radiance - the indirect radiance will give you direct radiance.  In this case the meter is setup to capture the UV portion of the spectrum.  Multifilter suggests that it can record radiance for bands of UV radiance so it would be tracking radiance on two or more ranges wavelengths.  The model described in this link supports six distinct frequencies though none are in the UV band.

The band rotates above the sensor occluding the light from the sun, when the radiance is at its lowest during the band rotating you are, typically, capturing the point where the direct sunlight is being filtered by the band.  When the band is not occluding the sun you would be capturing the highest radiance. The sampling rate would be setup in the datalogger or computer to allow radiance values at specific time intervals.

A short video of one in operation can be seen in this tweet.


Why would Earth have stable weather patterns if it stopped spinning and vigorous weather if it had a much faster rotation?

Weather modeling is crazy complicated so I don't want to make this sound absolute, but Venus virtually doesn't rotate and it has much faster trade winds than Earth.   Venus has low surface wind speed but that has to do with the consistent temperature all around it's surface and a very dense almost viscus atmosphere.

You might not get hurricanes with a slow rotation and virtually no Coreolis, but you'd still get weather.  The heavy cold air from the night side of the planet would sink and the hot day side of the planet would rise, and you'd get a constant re-balancing of density and a steady wind and likely a lot of rain as the air cooled on the night side, perhaps continuous rain at a certain time during the night (the same process that creates dew but much bigger).

Some good answers on a related question here.


Optimized interpolation method with fixed-location sample data points?

Welcome to an interesting and important field of research!

Interpolation is a large topic and there are many techniques. I agree that the GIS or math forum could be more initiated, but for completeness, I'll post some thoughts here.

The choice of method depends on the type of data you are using and the implementation depends on your environment. GIS software should always have a number of methods and parameters to adjust. It's also rather easy to create a script in e.g python or matlab to test and evaluate interpolation methods (E.g this).

Some questions to answer before you chose your method are:

Can I trust all my data? How much noise do I have?
Should only the nearest points be considered for the interpolation? How far should I 'feel' the values from data points?
How many dimensions should be interpolated? E.g. should I take time  into consideration?
Should the curves be as smooth as possible?
Should all interpolated values be in a specific range, within min-max of the whole data set or between the nearest points?
Do I know the total value? E.g. when interpolating population density I might know the total population and this could help me find the right interpolation method.
Process speed, that is an issue in your case might force you to choose a simpler technique.

Wikipedia has an overview and Caruso, C., and F. Quarta. "Interpolation methods comparison." Gives a rather good introduction of the techniques and there are some good webpages on GIS and interpolation.

The most important step is to test the method you choose. Again, there are various ways to do so, but the easiest is to simply leave points out from you data set and interpolate the values without them. Try to make the interpolated value as close to the data value as possible.

Kriging are methods based on the actual data instead of a curve. It's often a good first try on spatial data but also in other application like this.
Spline methods produces smoother curves. People doing computer graphics are experts on this, but there can also be applications where you'll aspect smooth changes in a model.

Naturally, more complex methods (e.g. kriging) take longer time to process, whiles simpler algorithms (e.g. bilinear or nearest-neighbor) are faster. Lower resolution of your output raster (array) would also speed up the process. You can let your resolution depend on the variance of the data, so that you interpolate less points in a flat surface and more points for a surface with higher relief. This techniques are common practice in signal processing and the experts are here.


Please explain how this rock could be shaped like this

These are fossil burrows... Looks like Thalassinoides or something similar. They are made by fishes, sea anemones, and crustaceans and can occur in different shapes... elongated, rounded, ending in t-sections, straight, spiral-shaped. A scalebar would be helpful for further classification.

Take a look at the Wikipedia page about it


How does high rate of evapo-transpiration contribute to the ineffectiveness of rainfall?

I just read the paragraph about the Effectiveness of Rainfall in UNIT.2 Climate of Pakistan, p. 30.

The author bring the topic of the rain being ineffective in a context where the rain is expected for crops and farming, or in other words, on the potential usefulness of the said rain for crops, which is quite low considering the climatic context in this area. I do not think the author is trying to explain the actual process of evapotranspiration for the area.

This is a summary of the factors bring by the author on why the current pluvial regime on Pakistan is not 'effective':

Rainfall is mainly from monsoon. Monsoon rain is not regular (and therefore unreliable for planning long term with rain as an only source of water). For instance ,distribution, amount and timing varies.
High temperatures during the monsoon season imply high potential evapotranspiration so a greater proportion of the rainfall is evaporated rather than infiltrated to be available for crop growth
Rain when it occurs is quite intense, with often a low infiltration rate and flow away instead of recharging ground moisture
Insufficient rain during winter to compensate

Therefore, irrigation and other means to store and distribute water should be used in the long term to efficiently use the water input, in regard with the potential use for water.


Can humanity help reinforce the ozone layer?

Would it be enough to simply vent ozone at point of manufacture, or would it be better released at the 10 km height?

Neither. The right answer is not to do it at all. Surface level ozone is deemed to be a pollutant. It is highly irritating to people. Ten kilometers is still in the troposphere. Ozone in the troposphere rarely makes its way to the stratosphere. Ozone is highly reactive, and there is plenty of stuff in the troposphere that ozone can readily oxidize. If this was to be done (which is a bad idea), the ozone would have to be released into the stratosphere. Ozone concentration peaks at about twenty kilometers altitude.
Why not at all? There are three billion metric tons of ozone in the stratosphere. Think of how much effort augmenting that would take, and how much ozone depleting chemicals would be deposited into the stratosphere while doing so. Jet engine and rocket exhaust contain chemicals that deplete ozone.


How to easily remember orientation of latitude and longitude?

I also mixed Longitude and Latitude until I heard someone saying '... at high latitudes.' in a conference talk.

In my mind, the picture of the Earth shows the Earth with the North and South poles at the top and bottom (or reversed, doesn't matter). High describes a vertical orientation. Therefore, the latitude changes in North-South direction.

Additionally, because the horizontal degree scale has a discontinuity at 360 degree (0 degree), it does not make much sense to distinguish high and low values in horizontal direction. Hence, high values are in vertical direction (= latitude).


Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

Water is a rather strange substance. With most substances, the solid phase is denser than is the liquid phase. This is not the case with water. Ice is less dense than liquid water. A side effect of this effect is that liquid water very close the the freezing point is less dense than is slightly warmer water. That very cool water sinks.

Liquid fresh water achieves its maximum density at a temperature of 4 °C (40 °F). This means that a pond or lake cannot freeze until the entire body of water is cooled to 4 °C. Only then can the upper surface of the water cool to below 4 °C, and then eventually freeze.

In addition to the water itself needing to be cooled to 4 °C before freezing can commence, the water-saturated ground beneath the pond has to be cooled as well. Until then, that warmer ground will transfer heat to the pond and keep it from freezing.

How long it takes before a body of water to first start freezing depends on a number of parameters. These include the size and depth of the body of water, the nature of the ground beneath the body of water, the weather leading up to the cold weather, and windiness. The question doesn't mention the depth of the pond, but it's only been below freezing in O'fallon, Missouri for about 24 hours, and temperatures had been quite balmy before that. That 24 hours span of sub-freezing weather is more than enough time to freeze a small puddle, but certainly not a lake, and probably not even a pond.

The question also mentions that it's windy. For a body of water to freeze, it needs a cooler layer of water atop the 4 °C thermocline. Winds act to keep the water well-mixed.


They don't really share a plate, now they did for a long time and the boundary between them is rather recent but they are separate plates.

BUT this was only discovered recently, recently as in 2012, so older references treat them as the same plate.  The "indo" in indo-australian plate is being dropped from more modern references.

The two plates are moving in almost the exact same direction and speed, so it is easy to see why it took so long to be discovered. Almost is also the key, the forces separating them up is rather weak, tectonically speaking, without a lot of heavy volcanics so the separation is very slow. Now they were not tightly connected to begin with, so there is no continental fault between them. Spreading centers


Is there scientific evidence connecting the current climate in India with global warming?

If you look at this link - Climate Of India there are four seasons affecting different regions of India

1) Pre monsoon showers 2) Indian Summer Monsoon 3) Post monsoonal rain. 4) Winter rain

Each of them have their own patterns and dynamics. From the perspective of the second and biggest impact on the country i.e. Indian Summer Monsoon it would be hard to find a single year where rainfall distribution has been completely well distributed i.e. all regions of the country had experienced surplus rainfall. But this unequal distribution would be made up in subsequent years mitigating drought. Or so it was thought.

For the monsoon to bring bountiful rainfall oceans must remain cool(relative to landmass) and land must warm during the crucial months of April and May. But this recent study published in Nature shows that there has been a  weakening of the land sea thermal gradient and drying up of Indian subcontinent/Drying up of Indian subcontinent due to weakening land sea thermal gradient. So according to that paper human influenced climate change causes the Indian  landmass to cool because increasing concentration of  aerosols suppress the surface warming.

Secondly there is an asymmetry in the El Nino forcing.

  Meanwhile, a recent study demonstrates that apart from the warming due to greenhouse gas forcing, the long-term warming trend in the western Indian Ocean is significantly associated with the asymmetry in the ENSO forcing. That is, while the quasi-periodic El Niño events induce a warming over the Indian Ocean via the Walker circulation, the La Niña events fail to do the inverse. Along with this, an increase in the magnitude and frequency of El Niños in the recent decades has accelerated this warming. The heat pile-up due to this ENSO forcing persists in the land-locked Indian Ocean that has a restricted thermohaline circulation, sustained by a feedback from the local air-sea interaction and ocean dynamics.

What this means is that the traditional monsoon dynamics i.e. cool Indian ocean and warm continental land mass has been disturbed by human influenced climate change as well as the natural geography of the land and ocean mass. One significant ISM phenomenon the tropical easterly jet stream has shown a  weakening trend over the last few decades. A significant fall out of this could be mid latitude atmospheric dynamics could come into play during the ISM(one can think of this as the weather during a break in monsoons where upper level subtropical westerlies come into play) and a disturbing trend has been noted in recent times with increasing frequency of hail storms.


If the Earth were a smooth spheroid, how deep would the ocean be?

An approximation can be obtained quite simply by dividing the volume of water in the oceans by the surface area of an ellipsoid with a smooth surface representing the idealized Earth in your question.

The volume of Earth's oceans, seas and bays is $1.332 \times 10^9 \text{ km}^3$.

The equatorial radius of Earth (semi-major axis of the spheroid) is $a = 6378.1 \text{ km}$. The polar radius of Earth (semi-minor axis) is $c = 6356.8 \text{ km}$.

The surface area of the oblate ($c < a$) spheroid is:

$$S = 2 \pi a^2 \left( 1 + \frac{1 - e^2}{e}\tanh^{-1} e \right)$$

where $e^2 = 1 - \frac{c^2}{a^2}$.

Which gives us $\approx 0.51 \times 10^9 \text{ km}^2$.

Dividing the volume of the oceans by this results gives us $\approx 2.6 \text{ km}$.

Note: Earth is not a sphere. An ellipsoid is a better representation of our Earth. Nevertheless, the answer to your question would have been approximately the same had I used a sphere instead, as suggested in the title of your question.