Blocking Anticyclone in the Atlantic Sector of the Arctic as an Example of an Individual Atmospheric Vortex

Abstract

The task of vortex boundaries setting is one of the most complexes in examination of factors influencing on the vortex (circulation system) development and destruction. In this study a new approach of vortex analysis as a whole system is proposed. It is based on vorticity equation where vorticity (left part of the equation) is defined as time coefficients of EOF-decomposition, which is integrated indexes characterizing individual vortex dynamics. Right part of the vorticity equation depicts internal and external factors influencing on the vortex. It's approbation is done on the example of an arctic-subarctic circulation system including blocking anticyclone in winter 2012 which persisted for a long time over the Atlantic sector of the Arctic and led to the formation of the largest positive air temperature anomalies and the minimum ice cover area in the Barents and Kara seas in the entire history of regular observations. It is shown that the main factor in long-term maintenance of the blocking anticyclone over the Arctic was vorticity advection, which was stabilized by horizontal heat advection.

Occasional Floods On The Rivers Of Russian Plain In The 20^Th –21^St Centuries

“…This leads to multiple increases in temperature in the winter, its transition through zero and changes in the phase of precipitation from solid to liquid. In addition, according to recent studies (Kislov et al 2017), anomalous amounts of precipitation play a significant role in blocking anticyclones. The Euro-Atlantic sector fully covers the ETR and experienced an increase in the frequency of blocking in the northern hemisphere during the 20 th -early 21 st centuries.…”

“…As the main method for processing the initial data, we used GrWat automated hydrograph partition algorithm (Kireeva et al 2019). Partly this algorithm based on the same principals, described in several research papers (Nathan and McMahon 1990;Eckhardt 2005;Shevnina 2013). As a result of this partition, four genetic components of the runoff were obtained for each day of the water year: base flow, thawed snow (main flood wave), thawed snow (thawing peaks during the winter) and rain.…”

Precipitation Extremes and Their Synoptic Models in the Northwest European Sector of the Arctic during the Cold Season

“…Intensive cyclones penetrate the Arctic more often during climate warming. In winter, this happens due to the modification of the regional circulation, the increase in meridional processes during blocking [28], and due to the increase in the open water zone (due to the reduction in the area of sea ice), in which it is easier for cyclones to move. Cyclones work as a positive feedback factor.…”