September 7 2023: Over the past week, the sea ice had a decrease, since last week, by a lower rate of 3.88%, from the level on 08/31/2023 of 4.638 M km2 to 4.458 M km2 for this week. The sea ice extent is still above the all-time lowest levels set in some past seasons like 2018 and 2020 and about equal to what it was in 2018 at this time of the year. We are now getting near the point of turnaround from sea ice decrease to increase and so we’ll see how that goes over the next few weeks; things are slowing down a bit and so perhaps we are near that transition point.
The negative sea ice anomaly this week was lower than the anomaly of -1.033 M km2 on 08/31/2023 to a lesser negative anomaly of -1.010 M km2 on 09/07/2023, and so a bit less anomalously negative for this time of year.
In the waters around Antarctica, 2023 stands out as an extremely low sea ice year. The record began in 1979 and the sea ice extent this current austral winter season is outside of 6 standard deviations (SD) for the time series. Note that the grey shading in our Arctic sea ice plots (like the one above) is usually two standard deviations, whereas the below plot for Antarctic waters shows six SD. The current situation around Antarctica is a truly extreme deviation from what could be considered normal for the austral sea ice season.