Hot in the Arctic
The recent Kaufman etal reconstruction of Arctic temperatures for the past 2,000 years has inevitably attracted a fair bit of controversy, not least because of it's distinctly 'hockey-stick' like appearance - caused by a sudden rapid warming trend over the past 100 years. The reconstruction itself used data up to 2,000 so any recent trends are not included, but it's interesting, in light of claims that such recent warming has not been as extreme as the reconstruction suggests, to look at a few recent reports and news stories (as much for ease of future reference as anything - no specific point is being made here!)
2005
Greenland witnesses record winter high temperature
2007
Record 22c temperatures in Arctic heatwave
Iqaluit sweats in record heatwave
2005
Greenland witnesses record winter high temperature
2007
Record 22c temperatures in Arctic heatwave
Parts of the Arctic have experienced an unprecedented heatwave this summer, with one research station in the Canadian High Arctic recording temperatures above 20C, about 15C higher than the long-term average ...... Scientists from Queen's University in Ontario watched with amazement as their thermometers touched 22C during their July field expedition at the High Arctic camp on Melville Island, usually one of the coldest places in North America.Arctic sets records on all fronts
2008Scientists have detailed what was an extraordinary melting season in the Arctic during the summer of 2007.
The record withdrawal of sea ice has been well documented, but the region also hit a number of other firsts.
Some ocean temperature measurements were unprecedented, and 2007 also set a new record for melting snow over the Greenland ice sheet.
Iqaluit sweats in record heatwave
On Monday, the mercury went up to a sizzling 26.8 C, which is the warmest reading on record for the city, Environment Canada said. It broke the previous record for July 21 by about 4 C.~ ~ ~The previous heat record was set on July 29, 2003, when the temperature went up to 26.1 C.
Melting ice threatens Arctic park
'Balmy' Eureka broke heat record in July
Conclusion: the last few years have been pretty warm in a number of parts of the Arctic, particularly the Baffin Island area. But we cannot deduce any conclusion with regards climate trends from this - though it is perhaps suggestive of anthropogenic warming excerbating any natural warming due to a combination of solar and oceanic forcing. The long term temperature trend for the Arctic is downwards, as would be expected under current orbital parameters which bring the Arctic furthest from the sun during it's summer and closest in the winter (alone this will not instigate a new glacial since the other Milankovoitch Cycles are not disposed towards full northern glaciation, but it should mean a cooling of the current extended interglacial, with a general advance in ice cover in the N Hemisphere - as indeed we saw during the Little Ice Age).
The climate record clearly shows previous warmer spells within the general downward temperature trend so in itself the current warm period is not exception - however the increase in temperature does appear to have been more rapid and has, for example, caused greater ice loss already in places like Baffin than occurred during the much longer Medieval Warm Period. Unfortunately it will be a few lifetimes before we know if the general cooling trend resumes or, as many suggest, human activity has brought the Neoglacial to a premature end.
It should be noted that there have been few reports of record winter cold in the Arctic in recent years, but lower latitudes have experienced some rather chilly winters of late. And most of these reported warm spells can be put down to synoptics - though one might argue that AGW has resulted in recorded temps being a little higher than might otherwise have occurred (others might argue that the synoptics themselves were different due to complex changes in the atmosphere caused by human activity. Or indeed, complex changes in the atmosphere caused by solar activity). As I said, no point is being made here. But it is clear that, regardless of paleoclimate reconstructions, there has been some warm weather in the Arctic in recent years with temperatures in places exceeding anything previously recorded. Coupled with increased ice melt (for whatever reason). One may draw whatever conclusion one wishes.
A national park in Canada's Arctic has been partly closed after record high temperatures caused flash flooding.Arctic air temperature at record high due to sea ice loss
Less summer ice - which deflects solar radiation - has resulted in a rise in both the ocean and atmospheric temperature.Baffin Island glaciers shrink by 50%
The US National Oceanic and Atmospheric Administration (NOAA) says autumn air temperatures in the region are at a record 5ºC (9ºF) above average.
Radiocarbon dating of dead plant material emerging from beneath the receding ice margins show the Baffin Island ice caps are now smaller in area than at any time in at least the last 1,600 years, said geological sciences Professor Gifford Miller of CU-Boulder's Institute of Arctic and Alpine Research. "Even with no additional warming, our study indicates these ice caps will be gone in 50 years or less," he said.2009
The study also showed two distinct bursts of Baffin Island ice-cap growth commencing about 1280 A.D. and 1450 A.D., each coinciding with ice-core records of increases in stratospheric aerosols tied to major tropical volcanic eruptions, Miller said. The unexpected findings "provide tantalizing evidence that the eruptions were the trigger for the Little Ice Age,"
'Balmy' Eureka broke heat record in July
Phillips said Eureka went up to 20.9 C on July 14, breaking the record of 20.7 C from July 23, 2007. Environment Canada started recording weather at the Eureka weather station in 1947.Eastern Nunavat's relentless warmth raises erosions concerns
This summer has been the warmest on record in the Baffin Island region, with temperatures several degrees warmer than normal in June, July and August, said David Phillips, senior climatologist with Environment Canada.Shrinking Bylot Glaciers
.....it became very evident that the glaciers on Bylot Island were, for the most part, retreating, shrinking, melting faster than ice could be produced,” he said. “For whatever reason, the summer melting was exceeding the winter snowfall.”
Conclusion: the last few years have been pretty warm in a number of parts of the Arctic, particularly the Baffin Island area. But we cannot deduce any conclusion with regards climate trends from this - though it is perhaps suggestive of anthropogenic warming excerbating any natural warming due to a combination of solar and oceanic forcing. The long term temperature trend for the Arctic is downwards, as would be expected under current orbital parameters which bring the Arctic furthest from the sun during it's summer and closest in the winter (alone this will not instigate a new glacial since the other Milankovoitch Cycles are not disposed towards full northern glaciation, but it should mean a cooling of the current extended interglacial, with a general advance in ice cover in the N Hemisphere - as indeed we saw during the Little Ice Age).
The climate record clearly shows previous warmer spells within the general downward temperature trend so in itself the current warm period is not exception - however the increase in temperature does appear to have been more rapid and has, for example, caused greater ice loss already in places like Baffin than occurred during the much longer Medieval Warm Period. Unfortunately it will be a few lifetimes before we know if the general cooling trend resumes or, as many suggest, human activity has brought the Neoglacial to a premature end.
It should be noted that there have been few reports of record winter cold in the Arctic in recent years, but lower latitudes have experienced some rather chilly winters of late. And most of these reported warm spells can be put down to synoptics - though one might argue that AGW has resulted in recorded temps being a little higher than might otherwise have occurred (others might argue that the synoptics themselves were different due to complex changes in the atmosphere caused by human activity. Or indeed, complex changes in the atmosphere caused by solar activity). As I said, no point is being made here. But it is clear that, regardless of paleoclimate reconstructions, there has been some warm weather in the Arctic in recent years with temperatures in places exceeding anything previously recorded. Coupled with increased ice melt (for whatever reason). One may draw whatever conclusion one wishes.
Comments
Post a Comment