Northern Europe's bulwark against Asian cold from 19-31. January 2013
Posted: 19. Jan.2013 (co-12-8)

Several regions of the northern hemisphere experienced already very cold periods this winter. Since the end of November 2012 temperatures have been -1.3 ° C below average in China , in the northeast of the country -3.7 ° C. So far it is the coldest winter in 28 years.

During a cold period in northern Europe in mid December 2012, significant sea ice appeared in the NE Baltic around 26/27 December (HERE), followed by moderate winter conditions for about three weeks. The sea ice diminished until 11^th January (Fig.1). Since then the trend reversed, and has now (19/Jan., Fig.2) almost reached the long-term average (Fig. 3). The status per 14^th Jan. is: HERE.

Is Northern Europe at risk to be rolled over from the still prevailing cold in Asia (Fig. 4)? In Stockholm , Tallinn and Vilnius temperatures were below -15° last night (Fig. 5). By the end of the month (31/01/13), the minimum T ° C (Fig. 6) is presumably still be low with sometimes 10 ° C below normal (Fig. 7). That Northern Europe during this cold phase is not turning out more severe can easily be extracted from the temperature graphs for the North- and Baltic Sea regions.

A significant heat is contributed from Baltic Sea , which continues (Fig. 7) until the end of January (Fig. 6). As mentioned above, the water temperature (SST) in the Baltic Sea is still in the normal range (Figure 2-3 and Figure 8-10). Further potential heat is present in the water column, as is indicated by the profile form three stations (Figure 11-14).

The conditions as per 19th January 2013 indicate clearly the enormous relevance of Baltic- and North Sea for the defense or mitigation of Siberian cold spells. Once the heat capacity of the regional seas is exhausted or low, such as in the three World War winters 1940, 1941 and 1942, HERE, then a cold air waves from the East penetrate much further westwards, with considerable lower temperatures toward the Atlantic coast.