Tornado Alley (PROG)

[F6]

fuagf -- and here's the "it's from Greenland" part:

Global warming is now slowing down the circulation of the oceans — with potentially dire consequences

According to the National Climatic Data Center, the world just saw its warmest winter ever…except for in one spot in the north Atlantic ocean (the deepest blue color above), which set a record for cold. Which is not good.
March 23, 2015
http://www.washingtonpost.com/news/energy-environment/wp/2015/03/23/global-warming-is-now-slowing-down-the-circulation-of-the-oceans-with-potentially-dire-consequences/ [with embedded video, and comments]
study:
Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation
Published online 23 March 2015
Abstract
Possible changes in Atlantic meridional overturning circulation (AMOC) provide a key source of uncertainty regarding future climate change. Maps of temperature trends over the twentieth century show a conspicuous region of cooling in the northern Atlantic. Here we present multiple lines of evidence suggesting that this cooling may be due to a reduction in the AMOC over the twentieth century and particularly after 1970. Since 1990 the AMOC seems to have partly recovered. This time evolution is consistently suggested by an AMOC index based on sea surface temperatures, by the hemispheric temperature difference, by coral-based proxies and by oceanic measurements. We discuss a possible contribution of the melting of the Greenland Ice Sheet to the slowdown. Using a multi-proxy temperature reconstruction for the AMOC index suggests that the AMOC weakness after 1975 is an unprecedented event in the past millennium (p > 0.99). Further melting of Greenland in the coming decades could contribute to further weakening of the AMOC.
http://www.nature.com/nclimate/journal/v5/n5/full/nclimate2554.html
in full: http://www.nature.com/articles/nclimate2554.epdf?referrer_access_token=Ks8t6HLCUr1Mzk9kG7fyAtRgN0jAjWel9jnR3ZoTv0NAhBvJD3qQKAFJ5ZYnRB2DfVKqstvbeSrKxpKUhj2SxF7BcI_loegLGlYCV27ok_Njli4FpCNFd520NkNH-gNy_R7BHOTlk8WVlOM-EydqJ_fXB_3x-E3hIshOeW5WWHqcaPgYVH6Ha2paJACMrQS0vL1bzMOuRrJUW7F2fIb6zTOfarfleGahqDJs4nRADLaiLU5g6rQIKxir0Igbm9o6CWHumkVB6-NveR4QQcF04yFUDA2eESQkZFHTbg4BEjL4NRYUqzDNwfzQCuzM7uRDnkxbaRldhwlXMVqQLfw_qA%3D%3D&tracking_referrer=www.washingtonpost.com

The Arctic is ‘unraveling’ due to climate change, and the consequences will be global
April 16, 2015
http://www.washingtonpost.com/news/energy-environment/wp/2015/04/16/the-arctic-is-unraveling-due-to-global-warming-and-the-consequences-will-be-global/ [with comments]
citing:
Arctic Matters
THE GLOBAL CONNECTION TO CHANGES IN THE ARCTIC
http://dels.nas.edu/resources/static-assets/materials-based-on-reports/booklets/ArcticMatters.pdf

Why NASA’s so worried that Greenland’s melting could speed up
August 29, 2015
http://www.washingtonpost.com/news/energy-environment/wp/2015/08/28/why-nasas-so-worried-that-greenlands-melting-could-speed-up/ [with comments]

New studies deepen concerns about a climate-change ‘wild card’
September 7, 2015
http://www.washingtonpost.com/news/energy-environment/wp/2015/09/07/new-studies-deepen-concerns-about-a-climate-change-wild-card/ [with comments]
studies:
Response of Atlantic overturning to future warming in a coupled atmosphere-ocean-ice sheet model
First published: 28 August 2015
Abstract
Climate change can influence sea surface conditions and the melting rates of ice sheets; resulting in decreased deep water formation rates and ultimately affecting the strength of the Atlantic Meridional Overturning Circulation (AMOC). As such, a detailed study of the interactive role of dynamic ice sheets on the AMOC and therefore on global climate is required. We utilize a climate model in combination with a dynamic ice sheet model to investigate changes to the AMOC and North Atlantic climate in response to Intergovernmental Panel on Climate Change scenarios for RCP4.5 and RCP6. It is demonstrated that the inclusion of an ice sheet component results in a drastic freshening of the North Atlantic by up to 2 practical salinity units, enhancing high-latitude haloclines and weakening the AMOC by up to 2 sverdrup (106 m3/s). Incorporating a bidirectionally coupled dynamic ice sheet results in relatively reduced warming over Europe due to the associated decrease in heat transport.
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065276/full
Gradual onset and recovery of the Younger Dryas abrupt climate event in the tropics
Published 02 September 2015
Abstract
Proxy records of temperature from the Atlantic clearly show that the Younger Dryas was an abrupt climate change event during the last deglaciation, but records of hydroclimate are underutilized in defining the event. Here we combine a new hydroclimate record from Palawan, Philippines, in the tropical Pacific, with previously published records to highlight a difference between hydroclimate and temperature responses to the Younger Dryas. Although the onset and termination are synchronous across the records, tropical hydroclimate changes are more gradual (>100 years) than the abrupt (10–100 years) temperature changes in the northern Atlantic Ocean. The abrupt recovery of Greenland temperatures likely reflects changes in regional sea ice extent. Proxy data and transient climate model simulations support the hypothesis that freshwater forced a reduction in the Atlantic meridional overturning circulation, thereby causing the Younger Dryas. However, changes in ocean overturning may not produce the same effects globally as in Greenland.
http://www.nature.com/ncomms/2015/150902/ncomms9061/full/ncomms9061.html [and see DesertDrifter's reply to the post to which this is a reply at http://investorshub.advfn.com/boards/read_msg.aspx?message_id=117792784 ]

Why some scientists are worried about a surprisingly cold ‘blob’ in the North Atlantic Ocean

January–August 2015 Blended Land and Sea Surface Temperature Percentiles.
September 24, 2015
http://www.washingtonpost.com/news/energy-environment/wp/2015/09/24/why-some-scientists-are-worried-about-a-cold-blob-in-the-north-atlantic-ocean/ [with comments]

Everything you need to know about the surprisingly cold ‘blob’ in the North Atlantic ocean
September 30, 2015
https://www.washingtonpost.com/news/energy-environment/wp/2015/09/30/everything-you-need-to-know-about-the-cold-blob-in-the-north-atlantic-ocean/ [with embedded video, and comments]