Climatologists Have Found Out How Quickly The South Pole Is Warming
Over the past 25 years, average temperatures at the South pole have increased by 0.6 °C every decade. This phenomenon is associated with periodic climate fluctuations in the tropical Pacific ocean. Climatologists came to this conclusion after analyzing data from American polar stations. Their findings are available in the scientific journal Nature Climate Change.
"Our data shows that the temperature at the South pole is rising about three times faster than the global average. This is due to a strong cyclone anomaly in the Weddell Sea. It is associated with rising temperatures in the tropical Western Pacific ocean. This once again shows that climate processes in the tropics and Antarctica are strongly linked," the researchers write.
Almost all climatologists do not doubt that global warming exists and that it will radically change the face of the planet if the increase in temperatures can not be contained at the level of 1.5 °C. This is evidenced not only by hundreds of computer models of the planet's climate, but also by data from climate satellites, land weather stations, and ocean buoys.
Practice shows that the first and primary victims of global warming will be the earth's polar regions and mountain glaciers. The temperature on their territory is already several degrees higher than in previous centuries. As a result, their area may be significantly reduced, and large areas of the Alps, Antarctica, and the Arctic will be freed from the ice.
A group of climatologists led by Professor James Renwick of Queen Victoria University (New Zealand) studied how the temperature changed at the South pole – the coldest and most inaccessible corner of Antarctica. In the past, as shown by measurements from aircraft, the temperature in its vicinity constantly fell due to the formation of the ozone hole, but over the past few decades, the situation may have changed.
To find out if it has changed, Renwick and his colleagues analyzed observations collected over half a century at the Amundsen-Scott polar station and other Antarctic bases. These data represent not only temperature fluctuations, but also how the pattern of their movement in the center of Antarctica has changed over the past forty years.
Natural warming of the Antarctic
It turned out that until the mid-1990s, the temperature at the South pole and in other regions of Antarctica did fall. However, in the next three decades, it began to grow sharply. In this respect, the South pole was different from other parts of Antarctica, where temperatures have been gradually increasing for more than 40 years.
After analyzing other climate factors unrelated to the formation and disappearance of the ozone hole, Renwick and his colleagues concluded that this warming was not due to human influence. Its cause, scientists believe, could be a sharp change in the nature of wind movement over the Whedell sea and tropical regions of the Pacific ocean.
These shifts, in turn, are associated with periodic climate fluctuations in the Western Pacific, the so-called Interdecadal Pacific oscillation (IPO, Interdecadal Pacific Oscillation). This phenomenon "switches" between the two modes every 15-30 years. Until the mid-1990s, IPO was in a "positive" phase, characterized by relatively high water temperatures in the tropics and low temperatures in Antarctica.
Then the oscillation went into a "negative" phase, which is accompanied by cooling in the tropics and the emergence of special atmospheric waves, thanks to which cyclones form in the Weddell Sea, and a large amount of heat is transferred to the vicinity of the South pole.
Because of this, the South pole took away the title of the fastest warming region of the planet from the Antarctic Peninsula, where temperatures in the past grew at almost the same rate. Now its warming has slowed significantly or even gone in the opposite direction, which, as researchers suggest, is also associated with the IPO.
The discovery of this phenomenon, according to Renwick and his colleagues, is important, because now it will be quite difficult for scientists to understand how much warming of the Antarctic is caused by anthropogenic CO2 emissions and how much of it is due to such natural factors. Subsequent observations, scientists hope, will provide an answer to this question.