We have grandchildren visiting this week, so it seems prudent to get the new open thread started a day early, and before they wake up!
The ARCUS Sea Ice Prediction Network July report has recently been published. Here’s the graphic overview of the 30 predictions for September sea ice monthly average extent:
The July median forecasted value for pan-Arctic September sea-ice extent is 4.66 million square kilometers with interquartile values of 4.51 and 4.87 million square kilometers, while individual forecasts range from 3.12 and 5.30 million square kilometers. We note the lowest forecast is an outlier, and the only forecast that predicts a new record September sea-ice extent value (current record is September 2012, with a sea-ice extent of 3.57 million square kilometers).
[Edit – August 1st]
Compared to the June SIO forecasts, the July median forecast is slightly higher (4.66 million square kilometers vs 4.54 million square kilometers), and the interquartile range is narrower (0.36 million square kilometers compared to 0.56 million square kilometers ), illustrating a lower inter-model uncertainty in the forecasts.
Extent is 13th lowest in the entire 44 year satellite record.[Edit – August 2nd]
The beginnings of this years “Laptev Bite” are now hazily visible from space:[Edit – August 5th]
The PIOMAS gridded thickness data hasn’t been released yet, but the main PIOMAS web page now has July’s graphs proudly on display:
[Edit – August 6th]
Average Arctic sea ice volume in July 2023 was 10,800 km3. This value is the 12th lowest on record for June, about 1900 km3 above the low record set in 2019. Monthly ice volume was 62% below the maximum in 1979 and 45% below the mean value for 1979-2022. Average July 2023 ice volume was 1.5 standard deviations above the 1979-2022 trend line. Ice growth (loss) for July 2023 was fairly normal for the recent decade, giving a mean ice thickness (above 15 cm thickness) in the middle of recent values. The ice thickness anomaly map for July 2023 relative to 2011-2022 shows more positive anomalies than negative ones.
CryoSat-2 has gone into its summer hiatus, though recent work (Landy et al. 2023) shows promised for summer retrievals. We’ll look at those at a later time.
Here’s a rare glimpse through the clouds of the fractured state of the sea ice around the North Pole:[Edit – August 9th]
The PIOMAS gridded thickness data for July has been released, so here’s the latest modelled thickness map:
Here too is the latest AMSR2 concentration animation:
There is now enough open water within the Arctic basin to allow storms to generate waves of a significant size.[Edit – August 15th]
There is now a storm spinning over the East Siberian Sea. It is creating significant waves which are directed at the ice edge to the north. Here is the surf forecast for 15:00 UTC today:
Here is the view from on high this morning:
P.S. As Aqua covers more of the Earth’s surface as the day progresses, more of the wide band of fragmented sea ice north of 80 degrees has become visible:[Edit – August 18th]
The PIOMAS mid month gridded thickness data has been released. Arctic sea ice volume is now 10th lowest in the satellite era, at 6,181 km3:
Here’s the associated thickness map:
Since the storm in the vicinity is still going strong, I cannot help but wonder how much of the arm of sea ice extending into the East Siberian Sea will remain this time next month:
Possibly as a side effect of the storm, JAXA extent is now fallen to the 2010’s average:[Edit – August 24th]
There are some interesting developments in and around Greenland at the moment. Surface melt has kicked in again, rather late in the summer season:
In addition the ice is breaking up off North East Greenland, leaving plenty of open water behind in the process:[Edit – August 25th]
The tenacious Arctic cyclone of August 2023 (TAC23 for short?) certainly seems to have had an effect on the sea ice in its vicinity. According to AWI’s AMSR2 concentration data the remaining ice in the East Siberian Sea has almost completely melted away:[Edit – August 26th]
The tenacious Arctic cyclone has finally wandered off into the CAA, with high pressure arriving in its wake. However in its place a sub 990 hPa low has now appeared off northern Greenland:
The conversation continues over on the September open thread.