Arctic Warming Accelerates
Washington Post article by Jason Samenow (February 1st, 2017), called ‘Beyond the extreme’: Scientists marvel at ‘increasingly non-natural’ Arctic warmth, presents a commentary on the radical warming that has occurred in the Arctic region during the past 12 months. This warming may be understood in terms of a metric called ‘Freezing Degree Days’, which is an account of the total time and temperature difference (Celsius) below freezing. The chart below shows the 2016-2017 anomaly in Freezing Degree Days for the region above 80 North Latitude (i.e. the Arctic). According to the Washington Post article, it is unclear if this new warming effect will continue or if it is a temporary fluctuation. The article includes a statement that cold polar high pressure systems over the Arctic usually block heat and moisture moving into the Arctic region from mid-latitudes, however with a weakening of these high pressure systems, storms originating in the Atlantic and Pacific Oceans can blow into the central Arctic thus bringing heat and moisture into the region – thereby creating the radical warming effect.
PIOMAS (Pan-Arctic Ice-Ocean Modeling and Assimilation System): The second and third charts are time series plots of sea ice volume in the Arctic (linked from the Polar Science Center, Applied Physics Laboratory, the University of Washington). The ice volume trend from 1979 to the present is shown in Chart 2 as blue; and the ice loss trend appears to be about 3000 km^3 of ice loss per decade since 1979. Shaded areas show one and two standard deviations from this trend. The actual ice volumes in the Arctic are shown in Chart 3 below.
Based on a continuation of the approximately linear ice-volume-decay trend line (Charts 2 and 3), it would appear that an ice-free Arctic Ocean could occur within 10 years (this is the author’s personal interpretation and not an official estimate).
Volume time series and uncertainties:
Schweiger, A., R. Lindsay, J. Zhang, M. Steele, H. Stern, Uncertainty in modeled arctic sea ice volume, J. Geophys. Res., doi:10.1029/2011JC007084, 2011
Zhang, J.L. and D.A. Rothrock, “Modeling global sea ice with a thickness and enthalpy distribution model in generalized curvilinear coordinates“, Mon. Weather Rev., 131, 845-861, 2003