This is a full million square kilometers (386,000 square miles) below the previous record low in 2022 – more than the size of Egypt.
The maximum, which was reached on 10 September, t was about 1.75 million square kilometers (676,000 square miles) below the reference mean (1981 – 2010), according to NSIDC.
This absence of Antarctic sea ice is associated with unseasonably warm sea-surface temperature across the Southern Ocean as well as warmer atmospheric surface temperature over much of wider East Antarctica and associated adjustment of the large-scale atmospheric circulation over the Antarctic.
Scientists with WMO’s Global Cryosphere Watch and the wider research community are monitoring whether this is part of the normal variability around the windswept frozen continent or whether it is the start of a new, worrying state as a result of excess greenhouse gases in the atmosphere and ocean.
“The 2023 Antarctic sea-ice deficit has direct impacts on the climate- and ecosystems, both nearby as well as far field, including at lower latitudes, which are home to the majority of human population and their economic interests,” said Dr Petra Heil, an expert from the Australia Antarctic Division and part of WMO’s Global Cryosphere Watch.
Antarctica’s huge glacial ice expanse and the surrounding sea ice cover are critical to regulating the climate because it reflects the sun’s energy back to the atmosphere and space.
In contrast, the dark ocean surface absorbs most of the sun’s incoming energy. So, less sea ice contributes to increasing temperatures – thus accelerating a vicious cycle.
”There is growing concern about rapid changes in the cryosphere – melting sea ice, ice sheets and glaciers,” says Omar Baddour, chief of climate monitoring at WMO. “The drop in Antarctic sea ice this year has been really dramatic. What happens in Antarctica and the Arctic affects the entire globe,” he says.