И.И. Борзенкова, О.К. Борисова, Е.Л. Жильцова, Т.В. Сапелко (2017) Холодный эпизод около 8200 лет назад в Северной Европе: анализ эмпирических данных и возможных причин. Лёд и Снег, Т. 57 , № 1

Уже более 20 лет в Северной Европе известен холодный эпизод около 8200 лет назад. Похолодание продолжалось около 160 лет, температуры воздуха снижались на 1–2 °С, а в отдельных районах – более чем на 3 °С. Предполагается, что снижение температур воздуха было связано с поступлением больших объёмов пресной воды в Северную Атлантику в результате распада и таяния ледников. Подобный механизм имеет прямое отношение к оценкам будущего климата при развитии современного глобального потепления. Поскольку таяние горных ледников и морских льдов в Полярном бассейне способствует опреснению верхнего слоя океана, при развитии потепления в районах, непосредственно прилегающих к Северной Атлантике, можно ожидать некоторого снижения температуры воздуха в высоких широтах.

Summary

Cold episode in Northern Europe happened about 8200 years ago was known for a relatively long time, mainly due
to paleobotanical (palynological) data obtained from analysis of lake and peat sediments. Detailed analysis of ice
cores from the Greenland holes GRIP, GISP2, and NGRIP with a time resolution of about 10 years made possible
to refine the duration and characteristics of the time structure of this cold period. This cooling lasted for approximately
160 yr. Spore-pollen analysis of lake sediments in Northern Europe (Sweden, Finland, Denmark, Germany,
the North and North-West of Russia) and deep-sea cores of the North Atlantic showed that the mean annual air
temperature during the maximum stage of the cooling was reduced by 1–2 °C, and in some areas by more than 3 °C.
The cold spread from the coast of the North Atlantic into the European continent and manifested itself mostly in
Sweden, Finland, the Baltic States, and to a lesser extent in the North-West and West of the Russian Federation. In
the central Russia and North of 70°N the cooling was weak or absent. The question about a nature of this cold event
and other cold spells in Late Glaciation, known as the cold of the early, middle and late Dryas, is widely discussed in
the scientific literature. Most of scientists accept a hypothesis proposed more than 20 years ago, that the reduction
of air temperatures in regions immediately adjacent to the North Atlantic was caused by the large volume of melt
water discharged into the ocean as a result of disintegration and melting of ice-sheets. Climate models that take into
account these effects allow estimating a decrease in the air and sea surface temperature due to freshening (desalination)
of the upper ocean layer, and this confirms that the greatest decrease in temperature should be observed in
the regions directly adjacent to the ocean. The increase in global temperature over the last 30 years is estimated to
be 0.8 ± 0.2 °C, which is already reflected in a noticeable increase in precipitation in high latitudes. In addition, the
melting of mountain glaciers and sea ice in the Arctic basin promotes freshening of the upper ocean, and as a result
of these processes one can expect a certain decrease in the air temperature in the high latitudes if the present-day climate
warming will continue. On the basis of paleoclimatic data, it can be assumed that such a decrease in air temperature
can be relatively small and occur only in areas directly adjacent to the North Atlantic.

citation: 
И.И. Борзенкова, О.К. Борисова, Е.Л. Жильцова, Т.В. Сапелко (2017) Холодный эпизод около 8200 лет назад в Северной Европе: анализ эмпирических данных и возможных причин. Лёд и Снег, Т. 57 , № 1
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publication_date: 
января, 2017