How much snow falls in Antarctica?

I'm finishing up a paper on the Antarctic ice sheet. One of my coauthors sent this through and I think it's one of the more interesting scientific diagrams I've seen.

Each dot is a place where we have measurements of surface mass budget- basically snowfall minus any melt or evaporation.

Then we compare each one of 5 climate models estimates with those measurements. In some place some models work better than in others. And in a lot of places the models work surprisingly well.

But.

There are vast areas with no measurements at all. Many of the measurements that do exist were only made a few times and often long ago.

Without these kind of observations we are almost blind as to what is happening in Antarctica. It is the largest potential source of sea level rise, especially in Northern Europe.