Here is ASL Environmental Sciences newsletter 2012 ASL Environmental Sciences provide scientific consulting services for Ice and Oceanographic Studies.
Thursday, July 12, 2012
ASL Environmental Sciences newsletter 2012
Here is ASL Environmental Sciences newsletter 2012 ASL Environmental Sciences provide scientific consulting services for Ice and Oceanographic Studies.
Southern Ocean Observing System Update
1st Issue of "SOOS Update":
SOOS is now producing a quarterly newsletter called SOOS Update, which will provide all Stakeholders, sponsors, endorsers and the SOOS community with regular updates on SOOS activities. Subscribe to the SOOS members database to receive these newsletters directly, or click here to download the first issue.
Geoscientists discover trigger for past rapid sea level rise
The process, named 'saddle-collapse', was found to be the cause of two rapid sea level rise events: the Meltwater pulse 1a (MWP1a) around 14,600 years ago and the '8,200 year' event. The research is published today in Nature.
Using a climate model, Dr Lauren Gregoire of Bristol's School of Geographical Sciences and colleagues unearthed the series of events that led to saddle-collapse in which domes of ice over North America became separated, leading to rapid melting and the opening of an ice free corridor. Evidence of these events has been recorded in ocean cores and fossil coral reefs; however, to date the reason behind the events was unclear and widely debated.
Ice domes up to 3 km thick (three times the height of Snowdon), formed in regions of high snowfall and higher topography, such as the Rocky Mountains. Together with the saddles – lower valleys of ice between the domes – these made up the ice sheet.
Towards the end of the last ice age, at the time of mammoths and primitive humans, the climate naturally warmed. This started to melt ice at increasingly high elevations, eventually reaching and melting the saddle area between the ice domes. This triggered a vicious circle in which the melting saddle would lower, reach warmer altitudes and melt even more rapidly until the saddle had completely melted. In just 500 years, the saddles disappeared and only the ice domes remained.
The melted ice flowed into the oceans leading to rapid sea level rises of 9 m in 500 years during the Meltwater pulse 1a event 14,600 years ago and 2.5 m in the second event, 8,200 years ago.
Dr Gregoire, lead author of the study, said: "We didn't expect our model to produce such a rapid sea level rise. We got really excited when we realised that the events we simulated corresponded to real events!"
In the model, Dr Gregoire found that saddle-collapse could explain a significant amount of the sea level rise observed: "The meltwater pulse produced by the saddle-collapse can explain more than half of the sea level jump observed around 14,600 years ago. The rest probably came from the progressive melting of ice sheets in Europe and Antarctica."
This research not only identifies the process which caused the melting of the North American ice sheet and the trigger for rapid sea level rises in the past, but also increases our understanding of the nature of ice sheets and climate change, allowing further questions to be posed and, with more research, answered.
Research like this allows climate and ice sheet models to be tested against evidence from the real world. If climate models are able to reflect patterns observed in natural records our confidence in them increases. This is particularly relevant where the models are also used to investigate the effect of climate change on ice sheets in the future.
More information: Paper: 'Deglacial rapid sea level rises caused by ice sheet saddle collapses' by Lauren Gregoire, Antony Payne and Paul Valdes in Nature
Journal reference: Nature
July Sea Ice Outlook reports are now available
The July SEARCH Sea Ice Outlook reports are now available! The Pan-Arctic Summary, Full Pan-Arctic Outlook, and Regional Outlook are available at:
http://www.arcus.org/search/seaiceoutlook/2012/july
With 21 responses for the Pan-Arctic Outlook, the July Sea Ice Outlook projects a September 2012 arctic sea extent median value of 4.6 million square kilometers. The consensus is for continued low values of September sea ice extent. It is important to note for context that the estimates are well below the 19792007 September mean of 6.7 million square kilometers. The quartiles for July are 4.2 and 4.7 million square kilometers, a rather narrow range given that the uncertainty of individual estimates are on the order of 0.5 million square kilometers. This is also a narrower range than last year, which was 4.0 to 5.5. The July Outlook is generally similar to the June Outlook; the July median is higher by 0.2 million square kilometers than the June estimate, but the quartiles are similar.
Just after the June Outlook was completed (based on May data), arctic sea ice extent briefly set record daily rates of loss. In June we saw the second-most cumulative loss in the satellite record since 1979, behind the record minimum extent for June in 2010. We also saw cases of early melt in some regions. The culprit for the rapid sea ice loss in early June was again the presence of the Arctic Dipole (AD) pressure pattern, but the pattern shifted towards the end of the month and ice loss slowed.
In addition to the Pan-Arctic Outlooks, there were five contributions to the July Regional Outlook report. The regional outlooks shed light on the uncertainties
associated with the estimates in the Pan-Arctic Outlook by providing more detail at the regional scale, including the Northwest Passage and Hudson
Bay/Hudson Strait shipping routes, Beaufort/Chukchi Seas, the Canadian Archipelago/Nares Strait, and Barents/Greenland Seas.
The SEARCH Sea Ice Outlook produces monthly reports throughout the summer that synthesize projections of the expected sea ice minimum, at both pan-arctic
and regional scales. For background on the Sea Ice Outlook, see the main Outlook website at:
http://www.arcus.org/search/seaiceoutlook/index.php.
http://www.arcus.org/search/seaiceoutlook/2012/july
With 21 responses for the Pan-Arctic Outlook, the July Sea Ice Outlook projects a September 2012 arctic sea extent median value of 4.6 million square kilometers. The consensus is for continued low values of September sea ice extent. It is important to note for context that the estimates are well below the 19792007 September mean of 6.7 million square kilometers. The quartiles for July are 4.2 and 4.7 million square kilometers, a rather narrow range given that the uncertainty of individual estimates are on the order of 0.5 million square kilometers. This is also a narrower range than last year, which was 4.0 to 5.5. The July Outlook is generally similar to the June Outlook; the July median is higher by 0.2 million square kilometers than the June estimate, but the quartiles are similar.
Just after the June Outlook was completed (based on May data), arctic sea ice extent briefly set record daily rates of loss. In June we saw the second-most cumulative loss in the satellite record since 1979, behind the record minimum extent for June in 2010. We also saw cases of early melt in some regions. The culprit for the rapid sea ice loss in early June was again the presence of the Arctic Dipole (AD) pressure pattern, but the pattern shifted towards the end of the month and ice loss slowed.
In addition to the Pan-Arctic Outlooks, there were five contributions to the July Regional Outlook report. The regional outlooks shed light on the uncertainties
associated with the estimates in the Pan-Arctic Outlook by providing more detail at the regional scale, including the Northwest Passage and Hudson
Bay/Hudson Strait shipping routes, Beaufort/Chukchi Seas, the Canadian Archipelago/Nares Strait, and Barents/Greenland Seas.
The SEARCH Sea Ice Outlook produces monthly reports throughout the summer that synthesize projections of the expected sea ice minimum, at both pan-arctic
and regional scales. For background on the Sea Ice Outlook, see the main Outlook website at:
http://www.arcus.org/search/seaiceoutlook/index.php.
2.8 Million Years of Arctic Climate Change from Lake El’gygytgyn, NE Russia
Fairbanks, Alaska, July 10, 2012— "To this point no one has much of any terrestrial record anywhere in the Arctic older than 125,000 years ago" said Julie Brigham-Grette, University of Massachusetts Amherst as she describes findings from the Lake El'gygytgyn (or Lake E) project to Office of Polar Programs Board Meeting at the National Science Foundation.
Brigham-Grette along with Martin Melles, University of Cologne Germany and Pavel Minyuk, North-East Interdisciplinary Scientific Research Institute in Magadan, Russia, undertook the core drilling of Lake E, a lake that sits today inside a basin formed by a meteorite that struck the earth 3.6 million years ago. From their findings so far Brigham-Grette confidently said, "This is not a back water lake in the middle of nowhere—it's actually a lake that is recording a global signal."
Science magazine published 2.8 Million Years of Arctic Climate Change from Lake El'gygytgyn, NE Russia (Science online 21 June 2012, in print July 13) describing some of the team's findings. But watch the video JBG Describes Research at Lake E to see and hear the enthusiasm and details as Brigham-Grette describes the findings of this remarkable discovery.
Unique glacier research facility in Yukon hit by federal cuts
Added by NEWS WIRE on July 11, 2012.
One of Canada's oldest and most celebrated scientific research stations is racing against the clock to avoid having to close its doors.
The Kluane Lake Research Station, located in the Yukon adjacent to the largest non-polar icefield in the world, is one of a handful of scientific outposts to have its funding cut by the federal budget.
The Kluane Lake facility, which celebrated its 50th anniversary last year amid a $2-million renovation, was told in the spring that federal funding for its operations would be immediately discontinued.
CBC News has learned that its scientists unleashed a flurry of phone calls and letters that resulted in a moratorium on the decision and an extension of money to the cash-strapped station, administered by the University of Calgary's Arctic Institute of North America, that will keep it alive for several more months.
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