Arctic Sea Ice in the First Half of the 20th Century: Temperature-Based Spatiotemporal Reconstruction.

Semenov, V. A.; Matveeva, T. A.

Global warming in the recent decades has been accompanied by a rapid decline of the Arctic sea ice area (SIA) in summer (11% per decade). To understand the reasons for such changes, it is necessary to evaluate the range of long-term variability of the Arctic sea ice in the period before a significant increase of anthropogenic emissions of greenhouse gases into the atmosphere. Current empirical data on the spatiotemporal dynamics of Arctic sea ice until the 1950s have significant gaps. In this study, monthly average gridded sea-ice concentration (SIC) fields in the first half of the 20th century are reconstructed using the relationship between the spatiotemporal patterns of SIC variability and surface air temperature over the Northern Hemisphere. The reconstructed data show a significant negative anomaly of the Arctic SIA (about 1.5 million km2 in September and 0.7 million km2 in March) in the mid-20th century, which is considerably larger than the corresponding anomaly in other gridded SIC datasets.

TWENTIETH century; SEA ice; GLOBAL warming; ATMOSPHERIC temperature; SURFACE temperature; GREENHOUSE gases

Izvestiya, Atmospheric & Oceanic Physics, 2020, Vol 56, Issue 5, p534

0001-4338

Academic Journal

10.1134/S0001433820050102