As the planet continues to grow hotter, scientists are keeping a very close eye on the polar regions, which threaten to release huge amounts of water and carbon as they warm and thaw. Among them is a group of Australian scientists stationed in the Antarctic, who have just reported the continent’s first-ever heatwave, which they expect to have significant impacts on the local ecosystem.
In early February, Antarctica reached a record temperature of 18.3 °C (65.5 °F), almost a full degree warmer than the previous record logged in 2015 of 17.5 °C (63.5 °F). The continent’s first heatwave was a separate event to this, but does further illustrate how the global warming trend is affecting the local climate and landscape.
Between January 23 and 26, scientists with the Australian Antarctic Program logged the first reported heatwave event at the Case research center in East Antarctica.
“Heatwaves are classified as three consecutive days with both extreme maximum and minimum temperatures,” says study author Dr Sharon Robinson. “In those three days in January, Casey experienced minimum temperatures above zero and maximum temperatures above 7.5 °C (45.5 °F) , with its highest maximum temperature ever, 9.2 °C (48.6 °F) on 24 January, followed by its highest minimum of 2.5 °C (36.5 °F) the following morning. In the 31-year record for Casey, this maximum is 6.9 °C (12.4 °F) higher than the mean maximum temperature for the station, while the minimum is 0.2 °C (0.36 °F) higher.”
The team expects that this exceptionally warm summer will have long-term consequences for Antarctica. The higher temperatures can cause heat stress on some of its organisms and, while the precise impacts won’t become entirely clear for years, the team already has some idea of what it means for the ecosystem.
“Most life exists in small ice-free oases in Antarctica, and largely depends on melting snow and ice for their water supply,” says Antarctic ecologist, Dr Dana Bergstrom. “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.”
The research was published in the journal Global Change Biology.
Source: Australian Antarctic Program
