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Daniel Bailey

You should email him & set that youngster straight. :)

While a nice & informative post (the best part was the visuals used), not up to the standards established by you, Patrick.

The Yooper

Mark Kosir

Awww... Poor Jeff Masters. I read his blog regularly. In his defense, he's more into weather, and not so much into climate. LOL

Steve Bloom

Has this recent paper (public copy) been discussed here? From the conclusions:

Instrumental air and AW temperatures in the Arctic during the 20th century and beyond display quasi-synchronous multidecadal oscillations that make isolation of the industrial warming trend difficult (3, 21). Basinwide observations since the 1980s detected multiyear events of AW spreading in the Arctic Ocean that featured both a strong warming and an increased inflow to the Arctic (7, 27, 28). Although we cannot quantify from our data the variability of previous AW inflow to the Arctic by volume, our temperature data series and the above observational link suggest that the modern warm AW inflow (averaged over two to three decades) is anomalous and unique in the past 2000 years and not just the latest in a series of natural multidecadal oscillations. Both effects—a temperature rise as well as a volume transport increase—introduce a larger heat input into the Arctic Ocean. Although there is no direct contact of the AAWL with the ocean surface in the Arctic, such an increased heat input has far-reaching consequences. The strong AW warming event in the Arctic Ocean in the 1990s caused a shoaling of the AW core and an enhanced heat flux to the surface (29), concurrent with decreasing sea ice (4). Recent oceanographic data from the Laptev Sea continental margin indicate the impact of warm AW-related water masses on the shallow (<50 m) shelf (30), a feature not observed before in a >80-year time series. The data also provide evidence for a significant heat flux to the overlying shelf waters (30). Even without any modification of the vertical heat transfer processes, the enhanced temperature contrast between the AW and the surface sea water freezing point (increased from ~5 to 7 K as identified here) leads to an increase in the vertical heat flux of ~40%. Any positive feedback mechanism will magnify the effect of this flux increase on the ice cover. Complementing the strong feedback between ice and atmospheric temperatures (1), warming of the AW layer, unprecedented in the past 2000 years, is most likely another key element in the transition toward a future ice-free Arctic Ocean. (emphasis added)

There are some interesting references I hadn't seen before. And oh yes, it's yet another goddamned hockey stick.

michael sweet

Earlier on this blog some posters suggested that if enough energy was lost this winter through the thin ice that there might be less energy to melt the ice in summer. The paper Steve links suggests that in addition to providing heat all winter to keep the ice from freezing as thick, the water is warmer to melt ice in summer. As more heat comes in through the Fram strait it must go somewhere. Hopefully the heat shoaling onto the Laptev Sea margin will not begin to melt the gas clathrates there.

Anu

@Steve Bloom
Thanks for the link. I've read it quickly, and added the paper to a growing list of papers I hope to re-read closely as the summer melt season progresses. I believe that the warming global oceans are the key influence on the imminent ice free Arctic summers. The oceans are warming pretty much monotonically and the Arctic sea ice volume is decreasing likewise - I don't see how nonmonotonic atmospheric patterns like the AO are supposed to explain these decade long ice volume decreases...

http://www.arsc.edu/challenges/pdf/annual_2008.pdf
Ebb and Flow
Maslowski’s approach differs from many of his
contemporaries. The details tell the story. While many
climate models, such as those used recently by the
International Panel on Climate Change (IPCC), set
their focus globally, Maslowski spotlights the Arctic
Ocean. Even supercomputers can handle only so much
information when taking on the sort of complex, high
resolution imagery and data some modelers use. Like
the difference between a group photo and a close-up,
the close-up provides finer detail. Maslowski’s model is
a close-up of the Arctic—and that detail, the detail only
possible with powerful parallel supercomputers, is the
“quantitative understanding” of the Arctic Ocean and its
effect on sea ice that Maslowski believes many people
underestimate.

Yes, that warm Atlantic Water (AW) beneath the halocline layer that you mention is very important, and is causing basal melt under the entire Central Arctic Basin, and it's only going to get worse. This vertical heat flux is much affected by the shallow Sea basins, such as the Laptev Sea, and by the wind/waves along the Marginal Ice Zones exposed as the sea ice melts away northwards.

http://findarticles.com/p/articles/mi_7619/is_201001/ai_n52370622/?tag=content;col1
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below
Journal of Physical Oceanography, Jan 2010 by Turner, J S
This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the halocline over the past few decades.
A simple calculation shows that there is enough heat in the intruding Atlantic water to melt all the ice in the Arctic in a few years if all the heat could be brought to the surface in this time.

... the required measurements and understanding of processes, including
1) interannual quantification of the oceanic heat fluxes into the Arctic from the Pacific and the Atlantic, and

2) quantification of the processes by which this heat may influence the sea ice (e.g., by upward heat flux either by diffusive or eddy processes, or by mechanical, topography-related processes).

Maslowski does high resolution modelling of these eddy processes along the Arctic Ocean shelves that the low resolution GCM's (that predict Arctic ice free summers by 2050) can't see.

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