winter 2009/10 was the coldest since long. All over Northern Europe the
temperatures had been permanently below the freezing point since the
Climate Summit in Copenhagen from 07-18 December 2009. During a cold
winter the Baltic Sea reacts with a corresponding icing, but not this
winter. Even in February the sea ice was modest. Attention got the Baltic
Sea only few days ago, when new report
informed the world that about 50 vessels got stuck in ice between
Stockholm and Helsinki around the 4th of March 2010, while the Finnish Ice
Service informed of an sea ice increase on the 8th of March
(Fig. 4 & 5). Have this circumstances a reason that science in the 21st
Century should be able to explain? A comparison between this winter and
the first war winter 1939/40 would not be a harm.
Although a detailed analysis is pending, there is little doubt that winter had been the coldest for many decades, stretching from England, to Finland, and NE Russia. In the middle of this cold area the Baltic Sea from the Kattegat to the Bay of Bothnia. Permanent minus temperature and the forming of sea ice are closely connected. If this assumption is correct, than the extent of sea ice should have reached a level as at the end of the 1980s, when there had been a corresponding cold winter, and a high level of sea ice. From the caver than the current ice cover is far away. The last full cover occurred in the winters 1939/40, 1941/42 and 1946/47, and the second war winter 1940/41 a similar high coverage has a the highest sea ice level in the 1980s (see: Fig, 1).
The sea ice conditions in February &
March 2009 (Source. FMI)
Can the modest ice cover until mid February, and the late increase during the first days of March in any way be attributed to the extensive shipping activities in the Baltic Sea?
Some consideration on two ice
Fig.6 DJF-Temp, Stockholm
Fig. 7, Highest Sea Ice cover
To identify the reason one should not look for distant events or cycles (.e.g. El Nino , or NAO) but consider the role and impact huge naval armadas and activities have had on the heat content of the regional seas. Since the 1st of September they criss-crossed the waters, shelled, mined, and bombed the enemy. The heat stored during the summer is quickly released, with the presumably inevitable consequence that General Frost could take reign very early, long, and severe.
A corresponding mechanism could have influenced the sea ice conditions during the last winter. Of course the naval farce are not the issue nowadays, but shipping. About 2000 sizable ships a permanently navigating the Baltic Sea, which means that this armada may turn the entire sea surface level over a depth to 7-10 meters in about twice a months (Fig. 8), with the consequence that: