Linkage of Spring Vegetation Dipole Pattern in Mid‐High Latitude Asia to Preceding Autumn Sea Ice Over the Barents‐Laptev Seas

Abstract

AbstractBased on the normalized difference vegetation index (NDVI) and empirical orthogonal function analysis, a “northeast‐southwest” dipole pattern of spring vegetation in mid‐high latitude Asia was detected. This pattern was revealed to be associated with the autumn sea ice concentration (SIC) anomalies in the Barents‐Laptev Seas on the interannual variability. Increased autumn SIC over the Barents‐Laptev Seas tends to increase spring NDVI over the west of Lake Baikal and decrease spring NDVI in the Russian Far East. Further analyses indicated that the sea surface temperature (SST) anomalies persisting from winter to spring over the Northeast Atlantic and the Northwest Pacific play an important role in such a relationship. Increased autumn SIC over the Barents‐Laptev Seas is associated with a teleconnection pattern over the mid‐high latitudes in the following winter, accompanied by anomalous anticyclonic circulations over the Northeast Atlantic and the Northwest Pacific. Such changes in the large‐scale circulations induce downward net heat flux anomalies over the Northeast Atlantic and the Northwest Pacific, thereby contributing to the warming of SST which may persist to spring and in turn influence the atmospheric circulations. The Northeast Atlantic SST warming in spring may evoke a downstream wave train and cause positive geopotential height anomalies over the west of Lake Baikal, which increases local temperature and hence the vegetation. The Northwest Pacific SST warming in spring may lead to negative geopotential height anomalies over the Russian Far East through a meridional wave train, consequently resulting in a decrease in local temperature and hence vegetation.