This is a new sad record in Antarctica, the coldest continent on the planet. It is in fact in this region that we record the lowest temperatures in the worldwith -89.2°C recorded at Vostok on July 21, 1983, and up to -93.2°C estimated by a NASA satellite on August 10, 2010.
Located in the southern hemisphere, Antarctica is in the middle of summer, from October to February. And it is obviously at this time of year that the area experiences its highest temperatures of the year, with a maximum in January and February: -10 to -30°C on average. As in the Arctic, the ocean around Antarctica freezes in winter and melts in summer: the size of the pack ice therefore follows the evolution of these temperatures.
>> Read also: A strange natural heat source is accelerating the melting of the Greenland ice cap
Antarctica: an ice cap of less than 2 million square meters
At the beginning of the 2010s, the Antarctic sea ice had experienced a significant increase in its extension, and a record for maximum extension had even been established in September 2014, the end of the austral winter, when for the first time we exceeded the 20 million km mark2. But since that date, there has been a significant reduction in its surface area. Conversely, it reaches its annual minimum at the end of the austral summer, that is to say between the month of February and the month of March with an average of 2.80 million km² on the reference period 1980-2010.
Until now, the record for the smallest extension was held by the year 2017 with a minimum of 2.17 million km² measured on March 3 according to data from the National Snow and Ice Data Center (NSIDC). Most this record is now broken, with an extension that falls below 2 million km² for the first time. Indeed, since February 20, all values have been below this symbolic threshold. On the 25th, a new record was observed at 1.924 million km².
Is global warming to blame?
As the NSIDC reports in a recent articleit remains to be determined whether the abnormally low values observed in recent years herald a real downward trend or simply the result of natural climate variability, which is particularly marked in this region of the world.
>> Read also: It’s no longer snowing in the Arctic, it’s raining!
The influence of particular weather patterns is however likely, with warmer than normal seas, generating strong winds that could push the ice towards lower and warmer latitudes. Global warming could thus be responsible for this low extension of the sea ice, without this theory being a real certainty for the moment. At last, scientists also point the finger at the responsibility of tourists.
© Photo 4440, Shutterstock
–
Tourists viewing a glacier on Antarctica, Paradise Bay, Antarctica.
—
83 tonnes of snow melt for every tourist visiting Antarctica
The austral summer is also the period when tourists and scientists travel to this isolated continent. During the 2019-20 season, there were no less than 74,000, or 32% more than in 2018-2019, and about double compared to ten years ago. These journeys are not without impact on nature, as they leave a physical imprint with lasting consequences. The reason lies in the polluting compounds released by planes and boats for the transport of visitors, but also by the diesel engines supporting the few buildings present.
A recently published study in Nature Communications explains that scientists sampled snow at 28 sites in Antarctica and found that black carbon levels were up to four times higher than in other parts of the continent. Worrying fact: carbon black reduces the albedo of snow and ice! As a result, the researchers calculated that 83 tonnes of snow melt for every tourist visiting Antarctica. The researchers point out that there are more ecological alternatives to diesel engines, but that the main cause of the melting of the ice would remain the increase in temperatures due to climate change.
>> VIDEO: Climate change is accelerating one of the world’s strongest currents
–
