In the past, much of East Antarctica has been spared from rapid climate warming due in part to ozone depletion.
Now, scientists at the Australian Antarctic Program recorded a heatwave event at Casey research station in East Antarctica. They recorded the highest ever minimum and maximum temperatures at Casey between 23 and 26 January this year.
University of Wollongong biologist Dr. Sharon Robinson said, “In those three days in January, Casey experienced minimum temperatures above zero and maximum temperatures above 7.5°C, with its highest maximum temperature ever, 9.2°C on 24 January, followed by its highest minimum of 2.5°C the following morning.”
“In the 31-year record for Casey, this maximum is 6.9°C higher than the mean maximum temperature for the station, while the minimum is 0.2°C higher.”
Australian Antarctic Division applied Antarctic ecologist, Dr. Bergstrom, said the warm summer would most likely lead to long-term disruption to local populations, communities, and the broader ecosystem. This disruption could be both positive and negative.”
“Most life exists in small ice-free oases in Antarctica, and largely depends on melting snow and ice for their water supply.”
“Melt water flooding can provide additional water to these desert ecosystems, leading to increased growth and reproduction of mosses, lichens, microbes, and invertebrates.”
“However, excessive flooding can dislodge plants and alter the composition of communities of invertebrates and microbial mats.”
“If the ice melts completely, early in the season, then ecosystems will suffer drought for the rest of the season.”
“Higher temperatures could also cause heat stress in some organisms.”
Australian Antarctic Division atmospheric scientist, Dr. Andrew Klekociuk, said the warmer temperatures were linked to above-average temperatures across parts of Antarctica, and other meteorological patterns in the Southern Hemisphere that occurred during the spring and summer of 2019.”
“These patterns were influenced in part by the early breakup of the ozone hole in late 2019, due to rapid warming in the stratosphere – the atmospheric region above 12 km altitude.”
“The upper levels of the atmosphere at the edge of Antarctica were strongly disturbed in the spring of 2019, and effects of this likely further influenced the lower atmosphere over Antarctica during the summer.”
- The 2019/2020 summer of Antarctic heatwaves. DOI: 10.1111/gcb.15083