Renewable Revolution

Figure 3. The map shows average ocean sea surface temperature (SST) and sea ice concentration for August 7, 2016. SST is measured by satellites using thermal emission sensors, which produce global data adjusted after comparison with ship and buoy data. Sea ice concentration is derived from NSIDC sea ice concentration near-real-time data. Also shown are drifting buoy temperatures at the ocean surface (colored circles); gray circles indicate that temperature data from the buoys are not available.

Credit: M. Steele, Polar Science Center/University of Washington

What is quite unusual this year is the early ice retreat and resulting ocean warming in the western Beaufort Sea and in the western East Siberian Sea. The extent of warming to the north of these two seas is also unusual, as well as the extent of this warming to the north.

These two areas typically melt out later in the season, when atmospheric heating rates have declined from their mid-summer peak. Thus the exposed ocean warms, but not all that much. This pattern was true during the record-setting year of 2012, when by the end of summer, these areas were substantially cooler than surrounding seas that had melted out earlier.

This year, however, the melt out was early and extensive enough that the ocean has already warmed substantially in these two areas.