There is a decrease in the rate of temperature increase in the Arctic. This was announced by Roshydromet in a review of hydrometeorological processes in the North Polar Region of the Earth for 2021. At the same time, the monitoring results confirm the general warming trend in high latitudes.
The positive anomaly of the average annual air temperature in the Arctic zone in 2021 remained and exceeded the limit by 2.9 °C.
In summer, there is a general decrease in the amount of ice in the Russian Arctic seas. However, difficult ice conditions can form in local areas and in some areas of the seas in the autumn-winter period.
The data analysis for a long period of regular observations suggests that the factors of warming in the Arctic latitudes, which sharply increased in the early 2000s, have been decelerating in recent years. Temperature increase, reduction of ice sheet and other factors of climate change tend to stabilize.
Temperature
In 2021, advection of warm air masses and positive average monthly air temperature anomalies prevailed in the polar region. Average annual temperature changes in the polar region were above the limit by 2.9°С, which was 1.1°С lower than in 2020.
Positive temperature anomalies were observed along the Northern Sea Route of the Arctic seas of Russia. The greatest changes were noted in the Laptev and Kara seas, and the least in the Chukchi and East Siberian seas. Compared to 2020, the average air temperature along the Northern Sea Route decreased by 2.9 °C - from 4.9 °C in 2020 to 2.0 °C in 2021.
Changes in the temperature of the Atlantic waters in the Arctic Ocean for the reporting period fully correspond to the values of the previous year, which indicates the absence of both positive and negative temperature trends. For the first time in the last 8 years, a decrease in the maximum temperature of Atlantic waters by 0.13 °C was found.
Ice sheet
The trend towards a significant reduction in the area of ice sheet in the Arctic Ocean continues. Over the past 50 years, the area of ice in winter has decreased by 700 thousand square km, and in the summer – by 2.7 million square km, which is larger than the size of the island of Greenland.
At the end of the winter increase the ice thickness in some areas of the coast, for example, in the southwestern part of the Kara Sea, the region of the New Siberian Islands and the coastal central part of the East Siberian Sea, approached the average annual values, growing to 150-200 cm. This is more than in previous years, which is related to a decrease in the overall air temperature in winter.
The area of ice according to calculations at the end of the period of growth (beginning of May) and the end of the period of destruction (beginning of October) is 13.5 and 5.1 million square km, respectively. The calculated volumes of ice in the Arctic Ocean for these dates amounted to 24.0 and 5.8 thousand cubic km. Thus, the decrease in ice area and ice volume during the summer season amounted to 8.4 million square km and 18.2 thousand cubic km, respectively.
The development of ice conditions in 2021 has maintained the trend observed in the last decade. After the anomalously light development of ice conditions in 2012, in all subsequent years, including 2021, the development of moderately low ice sheet (by 5–10% less than the long-term average values) was observed throughout the year, except for the summer period. In the summer period, there was a significant reduction in ice coverage and light ice conditions formed (the anomaly of ice coverage was 25–30% less than the long-term average values). However, in the autumn period (October-December) there is a very rapid increase in the area of ice and the sea is covered with new ice literally in 10-20 days.
The late onset of ice formation in the autumn period, but at the same time the high intensity of its development in November–December 2020, led to a rapid increase in the area of the ice sheet, but a slow increase in its thickness. The area of coast ice (fixed ice near the coasts of continents and islands) in all Russian Arctic seas was less than the long-term average values, except for fast ice in the western part of the East Siberian Sea. In mid-March, the total area of coast ice in the Russian Arctic seas amounted to 500 thousand square km at a rate of 586 thousand square km, which is 15% less than the average long-term values. At the same time, in the western part of the East Siberian Sea, coast ice was developed by 25% over the limit.
Source: IA "Komiinform"