Heat in Canada as a benefit for Greenland’s ice sheet | Polarjournal
From Kangerlussuaq, tourists can also reach the Greenland Ice Sheet relatively easily. Normally in July and August the streams and lakes at the edge of the ice are full to the brim with meltwater. This year everything is different, mainly thanks to the heat over Canada. Picture: Michael Wenger

The heat wave in the US and Canada has been beating record after record for weeks. According to meteorologists, the culprit is an unusually strong bulge in the jet stream that traps heat over the North American continent. But what is a hot catastrophe for the Canadians means a win a little further east, at least for the Greenland ice sheet.

According to experts from Danish research institutions in the Arctic, the Greenland ice sheet has recorded unusually high mass increases this July. Especially the northwest of the island, in the area of Davis Street, recorded increases of up to 30 millimetres on July 2. According to “Polar Portal”, the association of various Danish research institutes for the Arctic, this means a net mass increase of several gigatons per day compared to the 30-year average.

The two daily maps of “Polar Portal” show the mass gain (blue) and mass loss (red) of the Greenland ice sheet. This shows a large loss at the edges of the ice sheet and at the same time large increases on the west coast, a consequence of the heat over Canada. Graphic: Polar Portal, DMI, DTU, GEUS

Also the European satellite program “Copernicus”, which undertakes earth observations with several Sentinel satellites, reported on July 9 instead of melting processes the increase of the glaciers in Greenland with a picture of the Kangerlussuaqfjord. There, floods of meltwater should normally flow off the edges of the ice sheet and pour into the fjord. But the picture only shows the usual lakes and very dry riverbeds. Melt ponds and streams are also hardly visible on the ice surface.

The Sentinel-2 satellite’s image of the Kangerlussuaqfjord shows hardly any meltwater in the rivers and on the ice sheet surface. This indicates only low melting activity, unusual for the time of year. Image: European Union, Copernicus Sentinel-2 imagery

Experts say the reason for the unusual condition in the middle of the melt season is due to the heat wave that has had Canada in its grip for weeks. This has its origin in a very strong and unusual northward bulge of the jet stream. But this simultaneously traps cold air over northwest Greenland, leading to lower temperatures and more snow accumulation over the glaciers, the ESA agency writes. The Danish research institutes, to which the Danish Meteorological Institute belongs, also explain this phenomenon with the heat wave. On meteo maps, the cold air over the northwest of Greenland is clearly visible, extending to the northeast. On the other hand, Iceland and parts of Scandinavia are once again crossed by warm air zones. Below that, cold air over the North Atlantic again. This whole constellation has also led to the heavy rainfall and flood disasters in Europe.

The weather map shows the warm air (red) and cold air masses over the respective regions. Due to the weakly meandering jet stream and blockages, the air masses cannot circulate and remain over the corresponding regions to a greater or lesser extent, sometimes for weeks already. Map: Tropicaltidbits.com via Twitter

Does this mean that Greenland’s long-known, much-discussed, and much-doubted by skeptic sites overall warming is slowing down? Probably not, because although the temperatures are colder than normal, the same is not true for the ground temperatures. These are between 3° and 9°C, depending on soil depth, higher than the long-term average. This will cause Greenland’s permafrost soils to thaw even faster, releasing more methane andCO2 on the one hand, while on the other hand heat will remain stored in the wet soil and the permafrost soils will freeze less or not at all in winter. This means a huge problem for animals, plants and infrastructure. Another problem of the situation is the bush fires in Canada, where tens of thousands of square kilometres are in flames. The resulting smoke drifts with the winds from west to east and has now reached Norway and other European countries. This further reduces air quality in places affected by summer heat. So what is supposedly good news from Greenland might not be seen that way in other regions.

Dr Michael Wenger, PolarJournal

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