August 5, 2019 - Top of the World

Layers of frozen seawater cap the Arctic Ocean at the “Top of the World”. Sea ice expands dramatically each winter, usually reaching maximum extent in March. Through the long days of Arctic summer, the ice melts just as dramatically, reaching its minimum in September. These annual fluctuations have occurred for thousands of years. But the winter maximums and summer minimums have been trending to the negative in recent decades.

According to the National Snow and Ice Data Center (NSIDC), loss of ice extent through the first half of July matched loss rates observed in 2012, the year which had the lowest September sea ice extent in the satellite record. As of July 15, Arctic sea ice extent was 7.84 million square kilometers (3.03 million square miles). This is 1.91 million square kilometers (737,000 square miles) below the 1981 to 2010 average and nearly the same as the July 14, 2012 extent. Since the beginning of the month, the ice edge has receded in most coastal areas and the open water region in the Laptev Sea has expanded.

This was before a blistering heat wave struck Europe in the closing days of July, setting high temperature records in Germany, France, and the Netherlands. The heat wave also baked parts of the Arctic, including Greenland, where air temperatures rose to 10°C above average in some location, peaking above the freezing point for hours at a time at the summit of the Greenland ice sheet, triggering massive melting. On August 1, the Greenland ice sheet broke records by losing more water volume in one day than on any other day since records began in 1950, shedding 12.5 billon tons of water into the sea, according to a report by Earth, Space, and Science News. The last extreme ice melt in Greenland also occurred in 2012. As of August 2, scientists do not expect the loss of either the Greenland ice or Arctic sea ice to exceed the record-setting loss in 2012.

On August 1, 2019, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the Top of the World. Clouds swirl high over the smoother remnant ice cap over the Arctic Ocean. Greenland can be seen in the center, below the ice cap. Heavy smoke from a number of wildfires burning in Canada and Alaska can be seen hanging over the snow-free, brown land of North America to the west of Greenland.

Image Facts
Satellite: Terra
Date Acquired: 8/1/2019
Resolutions: 1km (12.1 MB),
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC