Instead of percolating into the ice, snow meltwater refreezes onto the ice surface, forming a layer of hard, glassy ice. Figure 1. Since 1978, satellites have monitored sea ice growth and retreat, and they have detected an overall decline in Arctic sea ice. Viruses, bacteria, algae, fungi, and protozoans inhabit sea ice, taking advantage of the differences in salinity, temperature, and light levels. Sea ice that survives one or more summers is known as multiyear ice. The permafrost is believed to hold at least twice as much organic carbon than the atmosphere; however, as permafrost thaws, these relative carbon concentrations may change. The 1981 to 2010 median is in dark gray. Mechanisms of summertime upper Arctic Ocean warming and the effect on sea ice melt, Journal of Geophysical Research, 115, C11004. Liquid ocean water has an average salinity of 35 parts per thousand. The microbial breakdown of soil organic matter is predicted to present increases in atmospheric carbon dioxide and methane gas, two of the primary greenhouse gases, and two large drivers of climate change. Workshop on observing, modeling, and understanding the circulation of the Arctic Ocean and Sub-Arctic Seas. Winds from the south in the Kara and Barents Seas also kept the ice edge from expanding in that region, and led to retreat of the ice edge within the Laptev Sea. Remote sensing also revealed a reduction of 3 percent per decade in Arctic sea ice extent from 1978, with particularly rapid losses occurring from the late 1980s. The brine volume and chemical composition of the solid salts are temperature-dependent. The National Snow & Ice Data Center (NSIDC) has measured and tracked sea ice extent in the Arctic over the past forty years. Ten days after the minimum extent was reached, the total extent climbed above 4 million square kilometers (1.54 million square miles) and by the end of the month the ice extent was tracking at 4.25 million square kilometers (1.64 million square miles), still second lowest in terms of daily extent. Below average temperatures prevailed over Greenland. The rate of ice loss during those six days was faster than during any other year on record. Figure 2a. We provide an update during the first week of each month, or more frequently as conditions warrant. Understanding the relationship between sea ice and permafrost may provide key information to better evaluate the dynamics of each individually. In Antarctica the large-scale sea circulation is dominated by westward motion along the coast and eastward motion farther offshore in the West Wind Drift (also known as the Antarctic Circumpolar Current). The vertical line represents the last data point plotted. Another month has passed, and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: November 2019 saw an above average sea ice volume increase according to PIOMAS (3834 vs 3553 km3 for the 2007-2018 period). The sensors measure microwave energy radiated from the Earth’s surface (sea ice and open water emit microwaves differently), which can be used to map sea ice concentrations. The different shades of gray over land indicate the land elevation with the lightest gray being the highest elevation. Frost smoke, open water, and new and young sea ice at a small lead surrounded by pack ice and icebergs in the Bellingshausen Sea, Antarctica. Explore NASA satellite data using interactive maps that show how the Arctic is changing over time. Sea ice undergoes large seasonal changes in extent as the ocean freezes and the ice cover expands in the autumn and winter, followed by a period of melting and retreat in the spring and summer. The Transpolar Drift exports large volumes of ice from the Arctic Ocean south through Fram Strait and along the east coast of Greenland into the North Atlantic Ocean. With these ecosystem changes, there is impact to predatory fish feeding dynamics, along with greater impacts to large animal and human consumers. Arctic sea ice extent ice hit an all-time low in September 2012, when the ice was determined to cover only 24% of the Arctic Ocean, offsetting the previous low of 29% in 2007. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for May, June, July, and August 2020. According to our colleague Jamie Morrison at the University of Washington, this summer’s pronounced retreat of ice north of the Laptev-Kara-Barents-Seas region is consistent with the effects of the positive winter AO.