Antarctic sea ice reaches a new record low.

The Antarctic continent is surrounded by less sea ice than at any time since satellite measurements began in the late 1970s.

This year is exceptional, according to the National Snow and Ice Data Center, because it is the southern hemisphere summer, when you would expect less sea ice.

On February 13, winds and warmer air and water reduced coverage to just 1.91 million square kilometers (737,000 square miles).

Furthermore, this summer’s melt still has a ways to go.

The previous record-breaking minimum of 1.92 million square kilometers (741,000 square miles) was not reached until February 25 of last year.

In the past seven years, three of the most recent record-breaking years for low sea ice have occurred: 2017, 2022, and now 2023.
On their circumnavigation of the continent, research vessels, cruise ships, and fishing vessels all report virtually ice-free conditions in the majority of regions.

Only the Weddell Sea is still dominated by floes of frozen water.

How extraordinary is this new record?
Scientists consider Antarctic sea ice behavior to be a complex phenomenon that cannot be easily attributed to climate change.

Using satellite data from the last forty years or so, the sea-ice extent exhibits significant variation. Only within the past few years is a downward trend toward dwindling summer ice amounts discernible.
It will soon begin growing again, and it is crucial that it does so… for a variety of reasons.

Freezing seawater at the ocean’s surface releases salt, causing the water below to become denser and sink.

This is a component of the engine that drives the great ocean conveyor – the mass movement of water that helps regulate climate system energy.

Additionally, sea ice is crucial to life at the poles.

In the Antarctic, the algae that adhere to the ice serve as a food source for the small crustaceans known as krill, which serve as an essential food source for whales, seals, penguins, and other birds.

The sea ice also serves as a platform for certain species to haul out and rest.

Warm air enhancing snowmelt
The unusually high air temperatures to the west and east of the Antarctic Peninsula likely contributed to this year’s record low sea ice extent.

These temperatures have been 1.5 degrees Celsius above the long-term average.
In addition, there is something known as the Southern Annular Mode (SAM) that plays a significant role in the region.

It describes variations in atmospheric pressure that influence Antarctica’s renowned westerly winds.

Currently, the mode is said to be in a highly positive phase.

This reinforces the prevalent westerlies and pulls them poleward.

Increased storminess helps to disperse floes, which are then pushed northward into warmer waters to melt.

The presence of an ozone hole over Antarctica and the increase of greenhouse gases in the atmosphere are likely responsible for the longer-term positive trends in the SAM, according to researchers.