To some extent, this is a wide question, because I do not know in which direction I should move.
I am using [Polymaps](http://polymaps.org/docs/) to show markers on a map. The markers are static but the visualization depends on the values of the input data. For the map I read the data like this:

```
    var b = read_function("data.json", function(a) {
        json_object = a
    });

    map.add(b.on("load",load))

```

This works well when the JSON files are relatively small. When I get above 30 MB in size, the browser starts to complain (slow, crashing etc.). I work with Numerical Weather Prediction (NWP) model data so I am mainly experienced with Fortran and Python and the data I hope to be able to show is for an entire model domain of 1.3 million points, that is 1.3 million markers. The JSON file with all this data takes up 1.1 GB.

Surely it is not wise to read this file at once and I do not want to show all markers at the same time anyway. The density of markers can be much lower when the zoom is low and show more and more as you zoom in.

So my question is, how should an amateur proceed? Do I perhaps need to create an API somehow that returns smaller JSON objects depending on the state of the map?