Happy P-day to you also.
Greenland's increase was seen beginning with 2018 impact to shore bird nesting.
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Nathan Senner, an ornithologist at University of Montana–Missoula not affiliated with Reneerkens’s research, agrees this summer’s reproductive crash in Greenland is exceptional: “A nonbreeding year is pretty extreme.” Senner says the case is reminiscent of 1992, when shorebirds suffered poor reproductive success after Mount Pinatubo in the Philippines erupted the prior year. The tropical volcano belched atmosphere-cooling particles over the planet—including the far north, causing cold summer temperatures in the Arctic. Nevertheless, a study of the eruption showed some birds did successfully reproduce that year.
Researchers elsewhere in the Arctic are also reporting unusually late snowmelt this year, with repercussions for shorebirds. Richard Lanctot, a researcher for the U.S. Fish and Wildlife Service, believes record late snowmelt inhibited nesting near Utqiavik (formerly Barrow) on the northern coast of Alaska. His group’s nest count this summer so far is among the lowest since they began monitoring in 2003. Shiloh Schulte, an avian ecologist who works in northeastern Alaska for the conservation nonprofit Manomet, says snowmelt was more than two weeks later than normal in his region. He noticed flocks of long-billed dowitchers and American golden plovers gathering to migrate south without breeding. “Everything needs to be timed perfectly for these birds to be successful,” Schulte says of the short Arctic summer. On Southampton Island in the Canadian Arctic Archipelago, shorebirds nested at less than half their typical densities due the late snowmelt, according to research scientist Paul Smith of Environment and Climate Change Canada. Even with similar trends throughout the North American Arctic, nowhere has been hit harder than eastern Greenland.
scientificamerican.com
Then in 2019, reversal of shrinking (growth, thickening. slowed flow) at the Jakobshavn Glacier was seen for the 3rd consecutive year.
Major Greenland Glacier Is Growing
Jakobshavn has spent decades in retreat—that is, until scientists observed an unexpected advance between 2016 and 2017. In addition to growing toward the ocean, the glacier was found to be slowing and thickening. New data collected in March 2019 confirm that the glacier has grown for the third year in a row, and scientists attribute the change to cool ocean waters.
earthobservatory.nasa.gov
The 2019 melt season showed signs that the more meridional jet stream last year placed Greenland in a high pressure/low cloud cover regime (a drought) and melting was aided by fewer than normal cloudy days on top of a low accumulation season earlier due to the "drought":
The key factors for surface mass loss and melting for Greenland in 2019 included: 1) exceptional persistence of anticyclonic conditions (high pressure) during the 2019 summer, promoting dry and sunny weather that enhanced the surface melt thanks to the melt-albedo feedback, and 2) low snowfall in the preceding fall-winter-spring, particularly in the high-melt areas of western Greenland.
High pressure was dominant along the northwestern side of Greenland and Baffin Bay for the core of the melt season in June, July, and August this year, driving warmer air toward the northern region of the ice sheet and leading to clear sky conditions that promoted solar-driven surface melting (Figure 4). As the thin winter snow cover melted away early in the summer, darker older ice was exposed. Clear sunny weather led to a very high run-off rate, resulting in large mass losses. Persistent high pressure over Baffin Bay drove some downsloping wind events along the southwestern coasts. Melting along the northern coast as simulated by MAR was the highest recorded since 1978.
The summer months were only moderately warmer than average relative to 1981 to 2010, roughly 1 to 2 degrees Celsius (2 to 4 degrees Fahrenheit) higher along the western coast. This confirms that the main driver of surface melt in 2019 was above average cloud-free days, not warm air temperatures as in the 2012 summer melt. This also explains the exceptional dry and sunny conditions at the south.
nsidc.org
The predominant pressure centered over North America was low pressure much of last year.
That was the yin to Greeland's high pressure yang. All the snow that might have fallen on Greenland ended up in The Palmer Index over here, putting the Mississippi Basin at great risk of flooding again.
I do not recall the NASA reference you mention. Over the next couple months we'll see how much this year's data rhymes with the newly trending indications seen so far. (after deciphering all the tortured explanations that somehow, global warming is causing whatever happens...no matter what it is.) |
