NASA Earth Observatory: “In November, the sea ice extent averaged 9.08 million square kilometers (3.52 million square miles)—the lowest November extent in the satellite record. The yellow line shows the median extent from 1981 to 2010, and gives an idea of how conditions this November strayed from the norm.” Also shows sea ice extent for previous years dating back to 1978. Hudson Bay was icebound in November not that long ago.
Something’s going on in the Arctic. As the Washington Post reported last month, the Arctic Ocean was far, far warmer than normal—about 20 degrees Celsius higher than average. (Meanwhile, the air over Sibera is at record cold levels.) According to the Post, the higher temperatures are the result of record low amounts of thinning sea ice, as well as warm air being brought north by an increasingly errant jet stream.
NASA has been tracking sea ice levels and thickness by looking at the age of the ice in the sea ice cap. The video above shows “how Arctic sea ice has been growing and shrinking, spinning, melting in place, and drifting out of the Arctic for the past three decades. The age of the ice is represented in shades of blue-gray to white, with the brightest whites representing the oldest ice.”
The ESA reports that their CryoSat satellite “has found that the Arctic has one of the lowest volumes of sea ice of any November, matching record lows in 2011 and 2012.” The animated GIF below shows the change in November sea ice from 2011 to 2016, as observed by CryoSat.
Several Yukon communities are built on permafrost. In the context of climate change, that’s something of a problem. CBC News reports on a six-year research project that has produced hazard maps of seven Yukon communities; the maps evaluate the risk to future development from permafrost melting, flooding and ground instability. [CCA]
A new digital elevation model of Alaska was released earlier this month. The result of a presidential directive to improve elevation maps of Alaska as a tool “to help to help communities understand and manage” the risks of climate change, the ArcticDEM project is a collaboration between the National Geospatial-Intelligence Agency (NGA), the National Science Foundation (NSF) and the University of Minnesota, among others. The unclassified data gives two-metre (or better) resolution across the state. Lower-resolution DEMs for the entire Arctic will follow next year.
Digital elevation data for Alaska had previously been poor; the National Geographic article leads with the point that Mars has better topographic maps than Alaska does. Most digital elevation data is collected by airplane—an impractical method in the far north; the ArcticDEM is based on stereo imagery from DigitalGlobe satellites. (As a comparison, the Shuttle Radar Topography Mission’s DEM resolution is 30 metres for the U.S., 90 metres elsewhere.)
NASA Earth Observatory: “Days of intense rainfall in August 2016 led to widespread flooding in southern Louisiana, as rivers swelled high above their banks and many crested at record-high levels. […] The animation above shows satellite-based measurements of the rainfall as it accumulated over the southern United States. Specifically, it shows rainfall totals every three hours over the span of 72 hours from August 12-14, 2016. These rainfall totals are regional, remotely sensed estimates, and local amounts can be significantly higher when measured from the ground.”
NASA: “NASA researchers have helped produce the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed— key information in better predicting how the ice sheet will react to a warming climate.”
Cartographer John Nelson, whose relatively new but infrequently updated map blog is Adventures in Mapping, recently posted the above map to Twitter: it shows the intensity and variability of drought in the United States over the past five years. It’s not necessarily an easy map to read at first glance, but it’s striking to look at nonetheless.
DigitalGlobe’s satellite imagery of the Fort McMurray wildfire, which uses “short wave infrared imagery (SWIR) to ‘cut’ through the smoke and identify the active footprint and burning hotspots” and reveals where buildings have been damaged or destroyed by the fire, can be viewed at Gizmodo and on DigitalGlobe’s own blog.
Here are some links to maps and satellite imagery of the wildfire that forced the evacuation of Fort McMurray, Alberta this week.
1. The fire is fuelled in part by abnormally high temperatures: 32°C (90°F) was reported earlier this week. The above temperature anomaly map, based on MODIS data from NASA’s Terra satellite, demonstrates how unusual these temperatures are: “The map above shows land surface temperature from April 26 to May 3, 2016, compared to the 2000–2010 average for the same one-week period. Red areas were hotter than the long-term average; blue areas were below average.”
NASA Earth Observatory: “Clouds may seem like distant, ephemeral features that have little to do with life on Earth. In fact, they affect everything from the viability of ecosystems, to how much carbon plants absorb, to the reproductive success of reptiles. So by mapping clouds, new research shows, scientists can indirectly map life.”