A year ago, the winter temperatures in the Barents Sea were already about 1 °C higher than normal. Through spring and summer the deviation from the mean temperature was reduced (0.5 °C), but towards the end of the year, the deviation increased rapidly. In January, the temperature of the Atlantic water entering the Barents Sea was almost 1.5 °C higher than usual. These high temperatures still prevail in March, and also reach further east.
Warmer Norwegian waters
Warm winters have been the trend in the Barents Sea for almost ten years, as high air temperatures during autumn and early winter have prevented the sea water from cooling down as much as usual. Moreover, mild winters and high water temperatures have reduced the amount of ice in the Barents Sea during winter.
Water along the Norwegian coast has also been warm the last two years, close to the warmest recorded. In the North Sea, the temperature at the beginning of the year was about 2 °C higher than average, and the Norwegian Sea is also warmer than usual. This indicates that the temperature of the Atlantic water coming in from the south is high as well.
Sea temperatures vary a great deal. Russian observations going as far back as 1900 show that after a cold start to the 20th century, the temperatures stated to rise around 1920, peaked towards the end of the 30s and reached a low point in the late 60s. Since then, temperatures have increased steadily, and since 1990 only three years, from 1995 to 1997, have had temperatures below the long-term mean.
These observations show that the rise in temperatures in the past 30 years has been part of a natural process, and that we may expect temperatures to drop again, according to natural variations. However, climate changes induced by human activity are likely to change these processes and are probably the reason behind the new heat record in the Barents Sea.
Nevertheless, the natural variations will most likely cause temperatures to drop in the next ten years and thus reduce the effects of these climate changes.
An ICES working group will meet in Ireland shortly after Easter to study the climatic conditions of the North Atlantic and identify the reasons for the increasing temperatures in recent years.