First heatwave recorded in Antarctica

 

Antarctica has experienced its first heatwave with scientists expressing fears about the long-term damage to animals, plants and ecosystems.

Australian Antarctic Programme scientists recorded the first reported heatwave event at Casey research station in East Antarctica during the 2019-2020 southern hemisphere summer.

Record high temperatures were also reported on the Antarctic Peninsula.

Casey recorded its the highest-ever maximum and minimum temperatures from Jan. 23 to 26.

A heatwave is classified as three consecutive days in which extremely high maximum and minimum temperatures are recorded.

During the stretch the minimum temperatures were above zero degrees Celsius while maximums were above 7.5 degrees Celsius.

On Jan. 24, a temperature of 9.2 degrees Celsius was recorded at Casey, 6.9 degrees higher than the mean maximum for the station and the highest temperature ever recorded there.

The morning after, the highest minimum temperature was 2.5 degrees Celsius.

Temperature records were also broken at research bases on the Antarctic Peninsula in February, with the average daily temperatures for the month exceeding the long-term means by between 2 and 2.4 degrees Celsius.

The findings were published on Tuesday in the Global Change Biology journal, with contributors including scientists from the University of Wollongong, University of Tasmania and the government agency Australian Antarctic Division.

The researchers said that, based on previous experience of anomalous hot summers in Antarctica, “we can expect a multitude of biological impacts to be reported in coming years, illustrating how climate change is impacting even the most remote areas of the planet.”

In a joint article published on The Conversation website on Tuesday, the authors said that Antarctica was “not immune” to extreme events predicted to increase in frequency and severity due to climate change.

“While the world rightfully focuses on the COVID-19 pandemic, the planet is still warming,” they said.

“Antarctica may be isolated from the rest of the continents by the Southern Ocean, but has worldwide impacts.

“It drives the global ocean conveyor belt, a constant system of deep-ocean circulation which transfers oceanic heat around the planet, and its melting ice sheet adds to global sea level rise.”

Study co-author Dana Bergstrom said that the hot summer would most likely lead to long-term disruption, which could be both positive and negative to local populations, communities, and the ecosystem.

“Most life exists in small ice-free oases in Antarctica, and largely depends on melting snow and ice for their water supply,” said Bergstrom, who is a principal scientist at the Australian Antarctic Division.

The study said that while meltwater flooding can provide additional water to these desert ecosystems, leading to increased growth and reproduction of some organism such as mosses, microbes, and invertebrates, excessive flooding can dislodge plants and alter the composition of communities of invertebrates and microbial mats.

Bergstrom said that if the ice melts completely early on, then there will be drought for the rest of the season.

Also, higher temperatures could cause heat stress in some plants and animals that have adapted to cold Antarctic conditions, she said.

Last month, scientists recorded the hottest-ever day in Antarctica as a heatwave melts the continent’s ice caps and snowpacks.

The temperature at Argentinian research station Esperanza Base, in the north of Antarctica, was 18.3 degrees Celsius on February 6, U.S. space agency NASA said.

It said the temperatures matched those in the U.S. city of Los Angeles, which is known for its warm weather.