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Post by numerouno on Aug 19, 2013 17:47:10 GMT
Magellan, thank you mate, insolation does work both ways, both increasing and decreasing the overall rate of ice loss compared to the average values.
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Post by magellan on Aug 19, 2013 17:53:38 GMT
Magellan, thank you mate, insolation does work both ways, both increasing and decreasing the overall rate of ice loss compared to the average values. What is the normal cloud cover level for the Arctic? Has the amount of solar short wave radiation reaching the earth's surface increased, decreased or remained constant over the past 30 years? Do you know? |
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Post by numerouno on Aug 19, 2013 18:40:24 GMT
"What is the normal cloud cover level for the Arctic?" This would depend on the location and the time of the year. High barometric pressures statistically equal more insolation. A value of 0.70 overall is given here: www.hindawi.com/journals/amet/2012/542093/ |
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Post by magellan on Aug 19, 2013 22:15:08 GMT
"What is the normal cloud cover level for the Arctic?" This would depend on the location and the time of the year. High barometric pressures statistically equal more insolation. A value of 0.70 overall is given here: www.hindawi.com/journals/amet/2012/542093/So clouds are the key role. |
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Post by icefisher on Aug 19, 2013 22:58:14 GMT
I have clicked through all those arctic temperature profiles at ocean.dmi.dk/arctic/meant80n.uk.phpI cannot find ANY year in which there is such an early drop in temperature as this year The arctic temperature has been below the daily mean for the whole of May, June, July and very likely August. Wow! Can anyone find another year like this in the records? Conditions this year in the Arctic are very unusual If it is anything to do with the sun it certainly will get very cold up there when the solar minimum sets in The arctic models that recreate the arctic conditions degrade rapidly back in time. But it is a reasonable bet that the last time these conditions existed was prior to satellites. How much prior is anybody's guess. |
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Post by sigurdur on Aug 19, 2013 23:46:47 GMT
“People seem to have this thought that all this storminess is unusual,” said Mark Serreze, an Arctic climatologist and center director at NSIDC. “Well it’s not. It simply isn’t. Summer is the time for cyclones.” Arctic summers are not calm. In fact, the months of August and September see a maximum amount of cyclonic activity. Not every summer is very stormy, but overall, the Arctic is the Arctic for a reason nsidc.org/icelights/2013/08/12/are-arctic-cyclones-chewing-up-sea-ice/ |
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Post by sigurdur on Aug 19, 2013 23:47:14 GMT
I don't know how to do the fancy thing so that only link shows and you click on that.
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Post by throttleup on Aug 20, 2013 0:33:49 GMT
Numo, are you saying that the warm air in the Arctic is what's causing the unusual cold spell? Insolation is a major factor in the Arctic summer, as the sun is up 24/7, and the area then gets the insolation of the tropics. If there is a prolonged overcast, as was the case over the past month(s) the temps will drop from from the average. The overcast, in turn, is caused by some major disturbances caused by the warm air pushing in from the south. There is no magic to this, or are you saying the mysterious cooling can set in within a month or so? I can understand that some people would love to see things that just aren't there.
Thanks for the response. No, I never thought there was any magic involved.
But I am a little slow.
If the Arctic is cold because of "prolonged overcast" which is caused by "warm air pushing in from the south" then... why doesn't the warm air from the south make the Arctic temperature go UP because it is, after all, "warm air?"
I never said anything about "mysterious cooling," however wherever I have lived I have noticed temperatures sometimes go up (or down) many tens of degrees in just one day. It's like... magic... |
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Post by numerouno on Aug 20, 2013 1:37:28 GMT
Numo,
Thanks for the response. No, I never thought there was any magic involved.
But I am a little slow.
If the Arctic is cold because of "prolonged overcast" which is caused by "warm air pushing in from the south" then... why doesn't the warm air from the south make the Arctic temperature go UP because it is, after all, "warm air?"Let me add the voice of an expert here: “The reason we have storms in the first place is that they do a job—transferring heat and momentum poleward,” Serreze said. In the Northern Hemisphere, winters are stormier because of the temperature gradient between the Arctic, which is dark and cold, and the equatorial regions, which are sunny and warm. “But embedded within that overall pattern, what happens on a regional basis can be quite different,” Serreze said. During an Arctic summer, temperature gradients develop between the Arctic Ocean and the snow-free land, forming the Arctic frontal zone, where the land heats up strongly in contrast to the ocean along the coast. Most cyclones generate along this frontal zone and then migrate into the central Arctic Ocean. From Neven's blog neven1.typepad.com/blog/2013/08/are-arctic-cyclones-chewing-up-sea-ice.html#more (my emph)
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Post by icefisher on Aug 20, 2013 2:01:05 GMT
Numo,
Thanks for the response. No, I never thought there was any magic involved.
But I am a little slow.
If the Arctic is cold because of "prolonged overcast" which is caused by "warm air pushing in from the south" then... why doesn't the warm air from the south make the Arctic temperature go UP because it is, after all, "warm air?"Let me add the voice of an expert here: “The reason we have storms in the first place is that they do a job—transferring heat and momentum poleward,” Serreze said. In the Northern Hemisphere, winters are stormier because of the temperature gradient between the Arctic, which is dark and cold, and the equatorial regions, which are sunny and warm. “But embedded within that overall pattern, what happens on a regional basis can be quite different,” Serreze said. During an Arctic summer, temperature gradients develop between the Arctic Ocean and the snow-free land, forming the Arctic frontal zone, where the land heats up strongly in contrast to the ocean along the coast. Most cyclones generate along this frontal zone and then migrate into the central Arctic Ocean. From Neven's blog neven1.typepad.com/blog/2013/08/are-arctic-cyclones-chewing-up-sea-ice.html#more (my emph) Numno did you not notice that Serreze is talking about 2012 and the question is about 2013? |
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Post by numerouno on Aug 20, 2013 9:22:16 GMT
Numno did you not notice that Serreze is talking about 2012 and the question is about 2013? The physics have not been changed from the last year. |
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Post by hrizzo on Aug 20, 2013 12:33:33 GMT
numerouno:
Old soviet joke:
"The future is settled, the past is not"
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Post by numerouno on Aug 20, 2013 12:40:47 GMT
numerouno:Old soviet joke: "The future is settled, the past is not" LOL indeed. |
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Post by magellan on Aug 20, 2013 13:11:55 GMT
Numno did you not notice that Serreze is talking about 2012 and the question is about 2013? The physics have not been changed from the last year. Are the physics well understood? If so, then it shouldn't have been a problem predicting 2013. From your source: www.hindawi.com/journals/amet/2012/542093/I wasn't aware that clouds were well understood. Apparently Mark Serreze has it all figured out, although he did say in 2010 the Bering Sea ice was a fluke and there was nothing to see. Every year since, the Bering Sea has been gaining ice. Maybe Serreze doesn't know as much as he or you think he does. |
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Post by magellan on Aug 20, 2013 13:40:09 GMT
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