They appear to have, in essence, two imaging modes. They are showing the higher-resolution-mode, with 100 meter pixels, which are made every 5 days. (They ge

They appear to have, in essence, two imaging modes. They are showing the higher-resolution-mode, with 100 meter pixels, which are made every 5 days. (They get global coverage every 5 days.) I'll bet there are very few clouds there, so almost all the images (~66 per year) will be OK. It turns out (http://www.tandfonline.com/doi/pdf/10.1623/hysj.51.1.98 http://www.tandfonline.com/doi/pdf/10.1623/hysj.51.1.98) that the lake is fed by a river which is in turn fed by Lake Titicaca (made famous by Beavis and Butthead). Almost all rain there falls from December to March, so the first two images would be fairly "wet" while the last one (from January) might be rather "dry". Of course, in December 2015, the lake totally dried up. Besides the climate sensitivity, they also have a water management problem, because the level in the downstream Popoo is controlled somewhat by releases from Titicaca. One more thing: this set of visual images finds lake extent by measuring the retreat of the shoreline. Another approach is to use radar to find the elevation of water bodies, directly, to high accuracy. That should happen in a couple of years when SWOT launches (https://en.wikipedia.org/wiki/Surface_Water_Ocean_Topography_Mission https://en.wikipedia.org/wiki/Surface_Water_Ocean_Topography...).