Climatic Variation of the Arctic Front during the Warm Period and their Infl uence on the Northern Landscapes

Abstract

The duration of growing seasons and the reaction of the plant component of landscape depending on the average position of the Arctic Front (AF) in different climatic episodes according to observations in the sub-arctic (tundra and forest-tundra) and boreal (northern taiga and middle taiga) landscapes in European Russia and in Western Siberia, north of 60° N, is analyzed. The dynamics of climatic characteristics such as gradients of temperature and precipitation, sum of air temperatures above +10° C (sum of active temperatures), Satellite Climatic Extremes Index (SCEI), vegetation index gradients (NDVI AVHRR (1982–2000) and NDVI MODIS (2000–2012)) was used for the estimation. The regularities of the active temperatures sum increase and slight moisture variation were found. It was caused by the quasistationary and increasing intensity of frontal processes at the Arctic front in summer. All these reasons will cause the advance of the boreal forests to the north.