Whereas the older version of the map showed only that part of the sea ice that permanently covered Arctic waters year round at that time, the new edition uses a 30-year median of September sea-ice extent from 1981 through 2010. September sea ice hit a record low in 2012 and is projected to decline further. The change means there is far more ice shown on the 2015 version of the map than on its predecessor.
The changes can be seen below: the 2006 map is on the left, the 2015 map on the right.
Now as Semeniuk’s piece points out, neither way is wrong. But all maps have a point of view, and it’s naive to think that this change was made in a value-neutral environment: this was the result of a conscious decision. The reason for that decision—that’s what’s interesting.
Earth Wind Map is a transfixing animated visualization of global wind forecasts, updated every three hours. It would be fine enough to enjoy passively, but you can play with it: click and drag to change the view, select from a variety of map projections and pressure levels. Via io9 and GIS Lounge, among many others.
This is a list of maps related to the flooding in southern Alberta (Calgary, Canmore, Bragg Creek, High River, Okotoks, etc.). This list will be added to as needed. Feel free to contribute additional links in the comments.
Hotter than usual? Yes. This map shows how much land surface temperatures during the week of June 17-24, 2012 have been above or below the average for 2000-2011. Now this map measures something very specific: land surface temperatures (LSTs) aren’t the same as air temperatures: “LSTs indicate how hot the surface of the Earth would feel to the touch. From a satellite vantage point, the ‘surface’ includes a number of materials that capture and retain heat, such as desert sand, the dark roof of a building, or the pavement of a road. As a result, daytime land surface temperatures are usually higher than air temperatures.” Via Bad Astronomy.
This animated map from NASA (Flash-only, sorry) illustrates global temperatures since 1880: “reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average.” News flash: the planet’s getting warmer. More information here.