Seasonal co-variability of surface downwelling longwave radiation for the 1982–2009 period in the Arctic

摘要

Trends and variability of the Arctic sea ice extent depend on various physical processes, including\udthose related to changes in radiative fluxes, which are associated with cloudiness and water vapour and, in turn,\udwith the atmospheric moisture transport over the Arctic. Aim of this work was: (i) to extract seasonal spatial\udpatterns of the co-variability between the sea ice concentration (SIC) and the surface downwelling longwave\udradiation (SDL) in the Arctic Ocean during the 1982–2009 period; and (ii) to estimate the correlation coefficients\udbetween these patterns and the indices associated to some climate oscillation modes (AO, NAO, PNA, PDO and\udAMO). Maximum Covariance Analysis (MCA) was the main technique used in this study. Among our results,\udwe highlight two areas of maximum co-variability SIC/SDL centered over the Barents Sea in winter and over\udthe Chukchi Sea in summer. In addition, some statistically significant correlations (at 95 %) between the spatial\udpatterns of co-variability and climate oscillation indices were assessed, e.g. with PDO and AMO in November–\udJanuary, with NAO and AMO in May–July, and with PNA in August–October.