Sea-ice cover anomalies in the Arctic Basin associated with atmospheric variability from multi-decadal trends to intermittent quasi-biennial oscillations

Polar research

Motoyoshi Ikeda¹ 

[1] Graduate School of Environmental Science, Hokkaido University N10W5 SapporoHokkaido 060-0810, Japan

关键词: Sea ice;    sea-level pressure;    Arctic;    interannual variability;    EOF analysis;   

DOI  :  10.3402/polar.v31i0.18690

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

Arctic Ocean sea ice has been diminishing since 1970, as shown by National Snow and Ice Data Center data. In addition to decadal variability, low ice anomalies in the Pacific–Siberian region have been occurring at shorter timescales. The influence of the widely-known Northern Annular Mode (NAM) occurs across all seasons. In this study, empirical orthogonal function (EOF) analysis was applied to sea-level pressure in National Centers for Environmental Prediction Reanalysis data for 1960–2007, showing the NAM to be the leading mode of variability and the Arctic Dipole Mode (ADM) to be the second leading mode. The ADM changes markedly across seasons. In autumn–winter, it has a pole over Siberia and a pole over Greenland, at opposite signs at a several-year scale, whereas the spring–summer ADM (ADMSS) has a pole over Europe and a pole over Canada. In the 1980s, the most influential mode shifted from the NAM to the ADM, when the Pacific sector had low ice cover at a 1-year lag from the positive ADM, which was ...

【 授权许可】

CC BY-NC