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Post by neilhamp on May 25, 2012 7:28:13 GMT
Thermostat Thank you for your extensive analysis My own rather simplistic opinion is based upon the significantly higher level of arctic sea ice extent which occurred this winter. We can only wait to see what happens this summer If you are correct then a new record low will almost certainly be set because 2011 came very close to breaking the 2007 low point. The table below is taken from the NSIDC site nsidc.org/arcticseaicenews/2011/09/Previous minimum Arctic sea ice extents Year Minimum Ice Extent Date in millions of square kilometers 2007 4.17 September 16 2008 4.55 September 18 2009 5.10 September 12 2010 4.60 September 19 2011 4.33 September 9 I was hoping for an upsurge to 4.5-4.6
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Post by magellan on May 26, 2012 3:21:03 GMT
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Post by thermostat on May 27, 2012 1:41:40 GMT
Thermostat Thank you for your extensive analysis My own rather simplistic opinion is based upon the significantly higher level of arctic sea ice extent which occurred this winter. We can only wait to see what happens this summer If you are correct then a new record low will almost certainly be set because 2011 came very close to breaking the 2007 low point. The table below is taken from the NSIDC site nsidc.org/arcticseaicenews/2011/09/Previous minimum Arctic sea ice extents Year Minimum Ice Extent Date in millions of square kilometers 2007 4.17 September 16 2008 4.55 September 18 2009 5.10 September 12 2010 4.60 September 19 2011 4.33 September 9 I was hoping for an upsurge to 4.5-4.6 neilhamp, Late season increases in Arctic Sea Ice extent maximum have not been a particularly informative indicator of ultimate Arctic Sea Ice extent minimum in recent years. Late season expansion of ice extent results in relatively thin ice that has been observed to melt in the initial phases of the annual Arctic Sea ice cycle. Factors that have been found to be more important include (but are not limited to) persistent summer weather patterns in the Arctic basin. For example, the anamolous summer of 2007 was characterized by a persistent weather pattern called the 'dipole anomaly', with persistent high pressure on the North American side and persistent low pressure on the Siberian side of the arctic. This weather system promotes the movement of sea ice through the Beaufort Gyre and also drives the Trans Arctic Drift, leading to export of Arctic Sea Ice into the Greenland Sea. Thus, in the unusual extensive melt of 2007, a large volume of ice was essentially expelled from the Arctic Ocean into warmer, more southerly waters. The recent breakup of sea ice in the Beaufort Sea was associated with such a 'dipole anomaly' earlier this year, demonstrating the impact of such weather features on the present Arctic Sea ice; which has been reduced in thickness over the years and is now more susceptible to fragmentation and displacement.
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Post by sigurdur on May 27, 2012 3:55:05 GMT
As things stand presently, looks to me like the minimum ice extent will be lower than 2007. I think sub 4.0 will stand once the season is over.
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Post by thermostat on May 31, 2012 1:52:20 GMT
As things stand presently, looks to me like the minimum ice extent will be lower than 2007. I think sub 4.0 will stand once the season is over. As the melt proceeds, the weather will drive events. This German site has some usefull forecasts of weather that Arctic Sea Ice Junkies like to follow; www.wetterzentrale.de/topkarten/fsecmeur.html(click on N-Hem under ECMFW, and peruse in particular 850hPa-Temp.,SLP to see the Arctic weather forecast)
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Post by thermostat on May 31, 2012 2:50:14 GMT
Over on the Arctic Sea Ice Minimum thread I see a comment that I have not adequately considered the late season freeze in the Bering Sea. Thus, again, let me reiterate, "Late season increases in Arctic Sea Ice extent maximum have not been a particularly informative indicator of ultimate Arctic Sea Ice extent minimum in recent years. Late season expansion of ice extent results in relatively thin ice that has been observed to melt in the initial phases of the annual Arctic Sea ice cycle. " In particular, and more to the point in contention here, there is no scientific evidence that some unrecognized natural cycle is driving current climatic trends in the Arctic, as shown in this graph from the University of Illinois (see summer sea ice extent graph) arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2010.png. if this link does not work, see "Time series of annual and seasonal sea ice extent from 1901-2010." arctic.atmos.uiuc.edu/cryosphere/ then click on the graph under "older products"
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Post by woodstove on May 31, 2012 4:20:00 GMT
Over on the Arctic Sea Ice Minimum thread I see a comment that I have not adequately considered the late season freeze in the Bering Sea. Thus, again, let me reiterate, "Late season increases in Arctic Sea Ice extent maximum have not been a particularly informative indicator of ultimate Arctic Sea Ice extent minimum in recent years. Late season expansion of ice extent results in relatively thin ice that has been observed to melt in the initial phases of the annual Arctic Sea ice cycle. " In particular, and more to the point in contention here, there is no scientific evidence that some unrecognized natural cycle is driving current climatic trends in the Arctic, as shown in this graph from the University of Illinois (see summer sea ice extent graph) arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2010.png. if this link does not work, see "Time series of annual and seasonal sea ice extent from 1901-2010." arctic.atmos.uiuc.edu/cryosphere/ then click on the graph under "older products" OK, got it. upload.wikimedia.org/wikipedia/commons/b/b8/Vostok_Petit_data.svg
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Post by thermostat on May 31, 2012 4:56:02 GMT
Over on the Arctic Sea Ice Minimum thread I see a comment that I have not adequately considered the late season freeze in the Bering Sea. Thus, again, let me reiterate, "Late season increases in Arctic Sea Ice extent maximum have not been a particularly informative indicator of ultimate Arctic Sea Ice extent minimum in recent years. Late season expansion of ice extent results in relatively thin ice that has been observed to melt in the initial phases of the annual Arctic Sea ice cycle. " In particular, and more to the point in contention here, there is no scientific evidence that some unrecognized natural cycle is driving current climatic trends in the Arctic, as shown in this graph from the University of Illinois (see summer sea ice extent graph) arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2010.png. if this link does not work, see "Time series of annual and seasonal sea ice extent from 1901-2010." arctic.atmos.uiuc.edu/cryosphere/ then click on the graph under "older products" OK, got it. upload.wikimedia.org/wikipedia/commons/b/b8/Vostok_Petit_data.svgwoodstove, Nope, you did not get it. You need to go to the University of Illinois Cryosphere site arctic.atmos.uiuc.edu/cryosphere/and scroll down to find the 'older products' (I understand that this is difficult and challenging) the determined will find "Time series of annual and seasonal sea ice extent from 1901-2010" and the internet saavy will figure out how to view the actual data, good luck.
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Post by thermostat on Jun 2, 2012 2:14:29 GMT
Given the complexity of accessing the Cryosphere today historical summary of Arctic Sea Ice Extent over the past 110+ years, I still think it is worthwhile for interested forum participants to find the 'older products' section on Cryosphere Today, arctic.atmos.uiuc.edu/cryosphere/ and click on the graph showing "Timeseries of annual and seasonal sea ice extent from 1901-2010." This historical data provides a useful context for evaluating the present Arctic Sea Ice extent data in relation to the anecdotal accounts of historical reduced sea extent that are often introduced into this discussion. The Cryosphere Today historical Arctic Sea Ice extent graph also provides a useful context for analyzing various hypotheses regarding recurring natural cyles as drivers of current reductions in Arctic sea Ice extent.
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Post by throttleup on Jun 2, 2012 15:41:20 GMT
She's baaaaaack....Clinton In Arctic To See Impact of Climate Change US Secretary of State Hillary Clinton took a first hand look Saturday at the way a warming climate is changing the Arctic, opening a once frozen region to competition for vast oil reserves. Experts here estimate the value of the Arctic's untapped oil alone -- not including natural gas and minerals -- at $900 trillion, making it a huge prize for the five countries that surround the Arctic if they can reach it. And with climate warming opening up some 46,000 square kilometres (18,000 square miles) a year that had once been bound in ice, the region is expected to burst open, not just with oil exploration but with East-West trade along a more accessible northern route. Returning from a tour of the Arctic coastline aboard a Norwegian research trawler with scientists and government officials, Clinton told reporters that she learned "many of the predictions about warming in the Arctic are being surpassed by the actual data." "That was not necessarily surprising but sobering," she said. more at: news.yahoo.com/clinton-arctic-see-impact-climate-change-151737949.html;_ylt=Ah1WILdA1EQA9lVG6YKBdFGs0NUE;_ylu=X3oDMTNpdDFpYW5qBG1pdAMEcGtnA2I1OTE0YmI4LTU0YzAtM2ZkMC1iY2VlLWFkYzM3MDA5OWMxMgRwb3MDNwRzZWMDbG5fTGF0ZXN0TmV3c19nYWwEdmVyAzMxNWUyMGUwLWFjYz
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Post by thermostat on Jun 4, 2012 1:56:06 GMT
Looking at the weather, the US Navy maps showing Arctic Sea Ice Drift continue to show a pattern promoting export from the Arctic Sea into the Fram straight. www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticicespddrf.htmlOf course, a similar persistent pattern in 2007 resulted in the record low Arctic Sea Ice Extent that was observed that year. More recently this pattern has not occurred through the summer and in contrast weather systems that promoted the spread of summer ice occurred. Nevertheless, increased in situ ice melt in the Beaufort Sea and on the Siberian Sea side contributed to the final, relatively low sea ice extent observed. Looking at the present forecast, www.wetterzentrale.de/topkarten/fsecmeur.html especially the lower troposphere 850hPa-Temp. SLP (Sea Level Temp). The forecast is for a strong high pressure system to develop north of Alaska and persist. This system would further facilitate the ongoing movement of relatively thick multiyear ice into regions where is would be more susceptible to summer melting. If the present pattern that has been promoting the trans arctic drift continues, Arctic Sea Ice Extent is likely to be reduced.
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Post by thermostat on Jun 4, 2012 2:21:29 GMT
Looking at the past century and in particular the most recent half century regarding the Arctic Sea Ice, the pattern of Sea Ice loss is obvious (for example, see the Timeseries of annual and seasonal sea ice extent from 1901-2010, under 'older products' at Cryoshpere today.
Most interesting is the observed acceleration in Arctic Sea Ice loss apparent from the past decade. One explanation that has been offered is that the increased mobility of the ice has altered the dynamics of the summer melt season. The more general concept of 'Arctic Amplification' is also relevant, but is less defined. The notion that this is all somehow due to some unrecognized 'natural cyle', lacks credible scientific support.
What is most interesting here is understanding details of the mechanisms that are driving the Arctic Sea Ice melt. Since it takes heat to melt ice, the sources and movements of the heat are quite interesting.
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Post by thermostat on Jun 6, 2012 2:33:23 GMT
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Post by thermostat on Jun 7, 2012 16:46:25 GMT
NSIDC has now posted their Arctic Sea Ice update for June nsidc.org/arcticseaicenews/It contains useful information for those estimating the minimal sea ice extent for this year.
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Post by trbixler on Jun 9, 2012 13:14:21 GMT
"Arctic discovery: Massive algae bloom raises crucial questions" "NASA has revealed its discovery of a massive algae bloom under the slowly diminishing Arctic ice -- a finding that made scientists' eyes pop. But does this never-before-seen phenomenon change the fate of this microscopic algae? Not long ago, this crucial plant life -- which produces much of the world's oxygen -- was reported in a century-long tailspin." "The U.S. Coast Guard cutter Healy, carrying researchers for the Icescape expedition in summer 2011, had traveled "62 or 72 miles into the ice pack" before stumbling over this phenomenon, she noted. So, yes, the phytoplankton could have been growing for a long time, Bontempi said, which she finds "fascinating." "Things are happening on this planet that we never knew existed."" www.latimes.com/news/science/sciencenow/la-sci-sn-arctic-ice-phytoplankton-20120608,0,6013071.story
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