At the beginning of July JAXA/ViSHOP Arctic sea ice extent is still “lowest for the date” in their record going back to 1979:
The PIOMAS sea ice thickness map for June 30th reveals that the previously thick ice in the Chukchi Sea has been noticeably thinning:
The associated volume graph shows that the 2025 curve has entered the pack of other recent years. and is now 4th lowest for the date:
Continue reading Facts About the Arctic in July 2025The New Year began with JAXA/ViSHOP extent lowest for the date in the satellite era, just below 2018 . Since then extent has reduced, and there is now a large gap:
The primary reason for this is the remaining open water in Hudson Bay:
In previous years Hudson Bay has been covered by sea ice by this time of year, but in 2025 a large area remains unfrozen in early January!
Due to the way PIOMAS handles the leap years the last gridded thickness data of 2024 is dated December 30th:
By December 30th Arctic sea ice volume had increased to 13.61 thousand km³, 2nd lowest for the date in the PIOMAS record:
The JAXA extent graph is currently not updating, so let’s begin this month with the latest AMSR2 sea ice concentration map from the Alfred Wegener Institute. Click the image to see a ~10 Mb animation of the last four weeks:
Note in particular the restart of export into the East Greenland Sea via the Fram Strait:
and the movement of ice within the Canadian Arctic Archipelago:
The PIOMAS gridded thickness data for September 2024 has been released:
Some “pleasure craft” are currently heading up the west coast of Greenland en route to the Bering Strait via Lancaster Sound and one of the assorted routes through the Canadian Arctic Archipelago. For those of you unfamiliar with the geography of the Northwest Passage, here are couple of hopefully helpful maps:
Whilst there is still ice blocking the route across Baffin Bay from Greenland, the Canadian Ice Service has already started daily coverage of the heart of the southern route through the Northwest Passage. There’s plenty of open water in Lancaster Sound and low concentration sea ice in Prince Regent Inlet:
Further south there is also open water in the Coronation Gulf, but the fast ice between Peel Sound and King William Island has not yet started breaking up:
This slightly cloudy satellite image of the Canadian Arctic Archipelago also shows that the exit of the northern route via McClure Strait into the Beaufort Sea is already navigable:
Continue reading The Northwest Passage in 2024The JAXA/ViSHOP web site is currently down, so here is the current OSI SAF extent graph for the end of May:
2012’s “June cliff” is almost upon us, and if 2024’s current trajectory continues extent will cross above 2012 for the first time since February in a week or so.
Here’s the GFS model’s current map of snow depth:
Melt ponds are now visible on the ice in the Laptev Sea:
Continue reading Facts About the Arctic in June 2024A change is perhaps even better than a rest? Let’s start February with a reminder that following close behind another recent Arctic cyclone, Storm Ingunn caused red weather warnings for high winds and avalanches in Norway two days ago:
By yesterday evening another long period, storm driven swell was arriving at the sea ice edge in the Fram Strait, and to a lesser extent in the Barents Sea:
By this morning Ingunn had merged with the remnants of the prior cyclone, as revealed in Climate Reanalyzer’s visualisation of the latest GFS model run::
Continue reading Facts About the Arctic in February 2024The 2023 Arctic Report Card has been published by the US National Oceanic and Atmospheric Administration (NOAA). All sorts of things are discussed in the report, but sticking to Snow White’s speciality of sea ice here’s an extract:
This satellite record tracks long-term trends, variability, and seasonal changes from the annual extent maximum in late February or March and the annual extent minimum in September. Extents in recent years are ~50% lower than values in the 1980s. In 2023, March and September extents were lower than other recent years, and though not a new record low, they continue the long-term downward trends:
March 2023 was marked by low sea ice extent around most of the perimeter of the sea ice edge, with the exception of the East Greenland Sea where extent was near normal. At the beginning of the melt season, ice retreat was initially fairly slow through April. In May and June, retreat increased to a near-average rate, and then accelerated further through July and August. By mid-July, the ice had retreated from much of the Alaskan and eastern Siberian coast and Hudson Bay had nearly melted out completely. In August, sea ice retreat was particularly pronounced on the Pacific side, opening up vast areas of the Beaufort, Chukchi, and East Siberian Seas. Summer extent remained closer to average on the Atlantic side, in the Laptev, Kara, and Barents Seas
The Northern Sea Route, along the northern Russian coast, was relatively slow to open as sea ice extended to the coast in the eastern Kara Sea and the East Siberian Sea, but by late August, open water was found along the coast through the entire route. The Northwest Passage through the Canadian Archipelago became relatively clear of ice, though ice continued to largely block the western end of the northern route through M’Clure Strait through the melt season. Nonetheless, summer 2023 extent in the Passage was among the lowest observed in the satellite record, based on Canadian Ice Service ice charts.
Tracking the motion of ice in passive microwave imagery using feature tracking algorithms can be used to infer sea ice age. Age is a proxy for ice thickness because multiyear ice generally grows thicker through successive winter periods. Multiyear ice extent has shown interannual oscillations but no clear trend since 2007, reflecting variability in the summer sea ice melt and export out of the Arctic. After a year when substantial multiyear ice is lost, a much larger area of first-year ice generally takes its place. Some of this first-year ice can persist through the following summer, contributing to the replenishment of the multiyear ice extent:
However, old ice (here defined as >4 years old) has remained consistently low since 2012. Thus, unlike in earlier decades, multiyear ice does not remain in the Arctic for many years. At the end of the summer 2023 melt season, multiyear ice extent was similar to 2022 values, far below multiyear extents in the 1980s and 1990s:
Estimates of sea ice thickness from satellite altimetry can be used to more directly track this important metric of sea ice conditions, although the data record is shorter than for extent and ice age. Data from ICESat-2 and CryoSat-2/SMOS satellite products tracking the seasonal October to April winter ice growth over the past four years (when all missions have been in operation) show a mean thickness generally thinner than the 2021/22 winter but with seasonal growth typical of recent winters:
April 2023 thickness from CryoSat-2/SMOS relative to the 2011-22 April mean shows that the eastern Beaufort Sea and the East Siberian Sea had relatively thinner sea ice than the 2011-22 mean, particularly near the Canadian Archipelago. Thickness was higher than average in much of the Laptev and Kara Seas and along the west and northwest coast of Alaska, extending northward toward the pole. The East Greenland Sea had a mixture of thicker and thinner than average ice:
An excellent analysis (IMHO!), but I do have one quibble. I was following events in the Northwest Passage very closely last summer, and according to the Canadian Ice Service on September 1st:
Prompted by a comment by Tom in the June open thread, the time has evidently come to open the 2023 Northwest Passage passage thread. First of all let’s get our bearings with the help of this map of the area:
and another map detailing the routes through Canadian Arctic Archipelago that have previously been successfully traversed:
As our starter for ten for 2023, there is already plenty of open water in the Amundsen Gulf, together with plenty of melt ponding on the remaining fast ice in Franklin and Darnley Bays:
By way of a change, which is allegedly as good as a rest, let’s start the new month with a very pretty and almost cloud free “pseudo-colour” image of the Lena Delta and adjacent areas of the Laptev Sea:
Laptev sea ice area decline has been in high gear recently:
At the beginning of May AWI’s high resolution AMSR2 extent metric is at the top of the historical range:
After a period of melt in the East Greenland Sea, export of sea ice from the Central Arctic via the Fram Strait has increased recently:
Sea ice area in the Barents Sea peaked in the first week of April and has declined steadily since then:
SMOS data is flowing again, and the gaps have been filled. Here’s the final pre melt ponding map of the spring:
It reveals large areas of thin ice that have recently developed in the Kara Sea. Here’s a pseudo colour glimpse of the region through the clouds:
Continue reading Facts About the Arctic in May 2023