Primary yields remain high & flat sea ice continues despite warmer temperatures – Watts Up With That?
Dr. Susan Crockford
NOAA every year Arctic Report Card The most is a brave effort to turn good and vague news into harbingers of catastrophic climate change. Primary productivity increased across most regions (Good news for wildlife) and although temperatures in the Arctic have been “twice as high” as in the rest of the world in recent years, summer sea ice ‘spiral of death’ did not materialize.
Oddly, there is no bad news about polar bears (most recent mention was in 2014). However, the media said that several hundred seabirds have died this year in the vast Bering/Chukchi Sea during the four months of summer 2022 is an omen. climate change disaster–although the authors of the NOAA report admit they have no convincing evidence to explain the phenomenon. However, here are some honest numbers pretty bright.
sea ice
The chart at the bottom of this graphicspreading out rather than aggregating to make changes appear more dramatic, making it easier to see a decreasing trend in sea ice extent since 2007 and winter (March) coverage almost unchanged.
arctic temperature
Compare the graph of Overall temperature of the Arctic in this composite chart with the sea ice chart above: note the lack of correspondence between mean temperature and sea ice extent since 2007.
Lost ice for many years
The essay by Meier et al also includes an interesting image, showing how the ice has changed over time over time since 1984. Note that multi-year ice is an inefficient habitat when marine life is conserved: annual ice The first (seasonally) on the continental shelf is the most productive and is therefore where the majority of polar bears, seals, fish, whales and seabirds are found. I don’t see much reason to mourn the decline of extremely thick multi-year ice (>4 years old, red line in graph below) as far as wildlife is concerned, especially because 2-3 year old ice cover can be used as shelter. The resting/predatory background for seals and polar bears in the summer hasn’t decreased since 2007.
sea surface temperature
a graph of sea surface temperature in August presented by the authors Timmermans and Lab shows how cold the weather has been over the past two years in the Chukchi Sea (where Pacific walruses vacation), reflecting the fact that the sea ice in the region has do not melt completely in summer.
primary productivity
Report of Frey et al this year updates those from several recent reports and confirms that primary productivity–meaning more food for seals, walruses and polar bears–remains high in summer due to less sea ice cover, especially in Barents Sea, Russian Arctic, Bering/Chukchi Sea. The authors conclude:
All regions continued to show positive trends in primary productivity over the period 2003-2022, with the strongest trends in the Eurasian Arctic and the Barents Sea.
Large areas have lower-than-average primary yields in 2022, particularly for the Beaufort Sea, East Siberian Sea, Greenland Sea and Baffin Bay (which is associated with above-average sea ice cover average in these areas)...
In the graph from the report below, note the slow overall increase in primary productivity in Hudson Bay and the Greenland Sea compared to other regions. The report specifically mentions “above average sea ice cover” as an explanation for the results in the Greenland Sea but not in Hudson Bay (not mentioned in the report). I wonder why? The Beaufort Sea (data not shown) is also clearly less productive than average due to high sea ice cover. These are the two most frequently mentioned areas as shown strong indication of the decline in health and survivability of polar bearsI due to lack of summer sea ice, but I’m sure it’s just a coincidence.
dead sea bird
A report of 450 species of seabirds that have died in the Bering Sea and southern Chukchi this year compared to previous years by Kaler et als is a bit of a head scratcher. They admit that they don’t really know why a large number of birds have died in recent years but often the end cause seems to be starvation. They suggest that this may be due to the decline in primary productivity caused by sea ice depletion, directly contradicting the report by Frey and colleagues a few pages earlier:
Seabirds are sentinels for the state of marine ecosystems, and these mass deaths have coincided with major ecological shifts due to the loss of range and duration of sea ice in the Bering and Chukchi Seas.…Although the specific cause of why seabirds die is still unknown, a reduction in the extent of sea ice and lipid-rich ice algae coupled with warmer ocean conditions may be related to.
A short report by the US Fish & Wildlife Service about 2016 phenomenon Note that seabirds can starve to death if they do not eat in four daysmaking them particularly vulnerable to any disruption in feeding, including storms.
The image below, provided in the NOAA essay, shows the high number of common homicides in 2015-2016 (event #7) overshadowing all recent events. Only about 450 birds died this year, a relatively small number compared to previous events.
Note that the common bird is probably the most common seabird in the area, and the population of Alaska alone is estimated. with 2.8 million birds in 230 colonies. It is therefore not surprising that many common murres die when conditions are tough, whenever that happens (e.g. detailed in the figure below for 1970).
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