Are there datasets like the global land-ocean temperature index for land surface temperature only? I have no background in climate science, but I've become interested in explanations of the so-called "global warming hiatus" from 1998-2013. One explanation that people seem to think is convincing comes from Karl et al who, if I understand correctly, say that the apparent hiatus could actually be an artifact of changes the way we calculate sea-surface temperature -- specifically that during that period we moved from primarily boat-based temperature measurements to primarily buoy and Argo float measurements. Since boat measurements are systematically a bit warmer than buoy measurements, the gradual switchover looks like a slight cooling trend when in fact it's just a difference in measurement technique.

I wanted to assess this argument for myself as well as I could, so I thought, if Karl et al are correct, then we shouldn't see evidence of hiatus in land-based datasets then, right? So I went in search of a dataset like NASA's global land-ocean temperature index but constrained to land only. I have found some very granular LST datasets (like this), but I don't think I've got the expertise I'd need to turn them into a yearly global timeseries (e.g. should I just take a straight mean of all the datapoints? Should I be weighing by landmass or seasonality, etc?).

So my question is, does a high-level aggregated yearly mean LST dataset exist? If not, why not? And at a higher level, does my approach to investigating the Karl et al work make sense, and if so has someone who knows what they're doing already done it?
Yes, NASA GISS has it here . If you go to the main page and search for 'Global Mean Estimates Based on Land-Surface Air Temperature Anomalies Only (Meteorological Station Data, dTs)' within that page you will find the links to the above, plus northern and southern hemispheres.