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[bluewave]

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[TerryM]

http://www.agu.org/p...1JC007102.shtml

Warm salty Atlantic Water is the main source water for the Arctic Ocean and thus plays an important role in the mass and heat budget of the Arctic. This study explores interannual to decadal variability of Atlantic Water properties in the Nordic Seas area where Atlantic Water enters the Arctic, based on a reexamination of the historical hydrographic record for the years 1950–2009, obtained by combining multiple data sets. The analysis shows a succession of four multiyear warm events where temperature anomalies at 100 m depth exceed 0.4°C, and three cold events. Three of the four warm events lasted 3–4 years, while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions. Three of the four warm events were accompanied by elevated salinities consistent with enhanced ocean transport into the Nordic Seas, with the exception of the event spanning July 1989–July 1993. Of the three cold events, two lasted for 4 years, while the third lasted for nearly 14 years. Two of the three cold events are associated with reduced salinities, but the cold event of the 1960s had elevated salinities. The relationship of these events to meteorological conditions is examined. The results show that local surface heat flux variations act in some cases to reinforce the anomalies, but are too weak to be the sole cause.

Full copy

http://ntrs.nasa.gov..._2011024624.pdf

Interesting - Could this be the positive natural variability so many have sought?

Any ideas on how rapidly this flows through the Arctic, and where penetration would be after 1, 2 or 3 years?

Another question arises - would mixing down to 500M disrupt this flow & if so what would the result be?

My knowledge of ocean currents would fit on a very small postcard.

Terry

[ORH_wxman]

Very interesting read. Thanks for posting. It almost sounds like shorter scale variability (of unpredictable length and onset) versus the longer term AMO cycle that was being discussed in the sea ice thread. Its a good demonstration of the uncertainty in the causes of some of these variable events.