Arctic Sea Ice Behaving Strangely Impacts Mid-Latitudes

The present loss of thick multi-year sea ice and the addition of extra ocean heat storage in newly sea ice-free areas support early and not easily reversible changes in the Arctic, disturbing the normal role of sea ice as a thermostat at the cold end of the global heat engine. Shifts in northern hemisphere wind patterns in autumn are directly connected to the current loss of summer sea ice. The primary factor in arctic change, and what separates the Arctic from mid-latitudes, is the function of sea ice. We keep experiencing surprises in the changing Arctic, such as the major loss of sea ice extent in the summers of 2007–2008, delayed fall freeze up in 2009, and the loss of much multi-year sea ice since 2005. While the emerging impact of greenhouse gasses is an important factor in the changing Arctic, what was not fully recognized until now was that a combination of anthropogenic warming, an unusual warm period due to natural variability (the Arctic Dipole), and sea ice working together, was enough to disrupt the memory and stability of the Arctic climate system. With continuing loss/retreat of summer sea ice to less than 20% of its climatological mean over the next decades, we anticipate increased modification of northern hemisphere atmospheric circulation patterns. Extensive regions in the Arctic during late autumn beginning in 2002 have surface air temperature anomalies of greater than 3°C;. These temperatures contribute to gradients in the 1000–500 hPa thickness field in every recent year with reduced sea ice cover, influencing subarctic winds directly and more distant regions through atmospheric teleconnections—wave like propagation of climate shifts. Ecological, economic and social impacts follow. This Arctic is behaving strangely, accompanied by northern hemispheric impacts, compared to the regionally isolated Arctic during days of AIDJEX in the 1970s.