Arctic Update II

curryja

14 years ago

by Judith Curry

Here is a synopsis of some recent papers and other issues in the Arctic

For background, previous threads on the Arctic:

Permafrost thaw – just how scary is it?

Arctic permafrost, and the possibility of massive methane releases into the atmosphere, has been in the news this past week. The Washington Post has a good overview of the issue with all the relevant links, in this article entitled Permafrost thaw – just how scary is it? Some excerpts:

One of the least understood — and one of the more unnerving — facets of climate change is the question of what will happen as the Arctic region heats up and permafrost in places like Alaska and Siberia thaws out. It’s a potent feedback mechanism, and scientists still aren’t sure just how potent it might be.

Meanwhile, Gillis’s piece — and the Nature survey — largely dealt with carbon that’s frozen in the northern soils. There’s a separate, though related, issue of what happens with the methane locked in frozen hydrates that’s buried in ocean sediment. There are thousands of gigatons of methane beneath the seas, comparable to the amount of carbon contained in the Earth’s coal deposits. And, as the Arctic waters warm, some of this methane is likely to bubble up into the atmosphere. Another troubling feedback.

So how worried should we be? Over the weekend, Justin Gillis had a beautifully reportedpiece in The New York Times on the permafrost question that summed up what scientists do and don’t know: “In the minds of most experts, the chief worry is not that the carbon in the permafrost will break down quickly — typical estimates say that will take more than a century, perhaps several — but that once the decomposition starts, it will be impossible to stop.” There’s no looming apocalypse, but melting permafrost could make it much harder to avoid setting the planet down a path of irrevocable warming.

The problem is that scientists have had similar difficulties getting a handle on just how much methane actually is bubbling up, since the Arctic isn’t exactly an easy place to take measurements. It can also be unclear whether observed methane plumes are new developments related to current warming or long-standing natural trends. At the moment, despite some frightening headlines in the British press, there doesn’t seem to be a “methane time bomb” ready to go off. Read Andy Revkin or University of Chicago ocean chemistDavid Archer for more context here. There’s no need for lurid Hollywood disaster-movie scenarios. The reality of what’s actually transpiring is apocalyptic enough.

Drilling for oil in the Arctic

BOEM conditionally approves Shell Arctic drilling . Some excerpts:

The federal Bureau of Ocean Energy Management on Friday conditionally approved a plan by a subsidiary of Royal Dutch Shell to drill exploration wells in the Chukchi Sea off Alaska’s northwest coast.

One condition will be lopping 38 days off the drilling season to make sure the company has enough time to cope with a spill or a wellhead blowout before sea ice moves into the drilling area.

Canada National Energy Board keeps Arctic drilling provisions. Some excerpts:

Canada’s National Energy Board said on Thursday that any company that wants to drill for oil and gas in Arctic waters will need to demonstrate it has the capacity to sink a relief well in the same drilling season to cope with possible well blowouts.

In Russia, oil spills are ravaging habitats. Some excerpts:

On the bright yellow tundra outside this oil town near the Arctic Circle, a pitch-black pool of crude stretches toward the horizon. The source: a decommissioned well whose rusty screws ooze with oil.

Environmentalists estimate that at least 1 percent of Russia’s annual oil production, or 5 million tons, is spilled every year. That is equivalent to one Deepwater Horizon-scale leak about every two months. Crumbling infrastructure and a harsh climate combine to spell disaster in the world’s largest oil producer, responsible for 13 percent of global output.

Oil, stubbornly seeping through rusty pipelines and old wells, contaminates soil, kills all plants that grow on it and destroys habitats for mammals and birds. Half a million tons every year enter rivers that flow into the Arctic Ocean, the government says, upsetting the delicate environmental balance in those waters.

Interannual to decadal variability of Atlantic Water in the Nordic and adjacent seas

J.A. Carton, G.A. Chepurin, J. Reagan, S. Hakkinen

Abstract. 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.

Citation: JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 116, C11035, 13 PP., 2011 doi:10.1029/2011JC007102 (link to abstract and partial figs)

Key Points

Nordic Seas region is subject to strong decadal ocean variability
The ocean variability is mainly due to changes in the inflow of Atlantic Water
The most recent anomaly began in 1999, is massive, and continues

Arctic warming, increasing snow cover, and widespread boreal winter cooling

J.L. Cohen, J.C. Furtado, M. A. Barlow, V. A. Alexeev and J. E. Cherry

Abstract. The most up to date consensus from global climate models predicts warming in the Northern Hemisphere (NH) high- to mid-latitudes during boreal winter. However, recent trends in observed NH winter surface temperatures diverge from these projections. For the last two decades, large-scale cooling trends exist instead across large stretches of eastern North America and northern Eurasia. We argue that this unforeseen trend is likely not due to internal variability alone. Instead, evidence suggests that summer and autumn warming trends are concurrent with increases in high-latitude moisture and an increase in Eurasian snow cover, which dynamically induces large-scale wintertime cooling. Understanding this counterintuitive response to radiative warming of the climate system has the potential to improve climate predictions at seasonal and longer timescales.In press, Environmental Research Letters.

Link to full paper [here]. (h/t Alex Pope).

Arctic warming is not greenhouse warming

Arno Arrak

Abstract. After two thousand years of slow cooling Arctic, warming suddenly began more than a century ago. It has continued, with a break in the middle, until this day. The rapid start of this warming rules out the greenhouse effect as its cause. Apparently the time scale of the accumulation of CO2 in the air and the Arctic warming does not match. It is likely that the cause of this warming was a relatively sudden rearrangement of the North Atlantic current system at the turn of the century that directed warm currents into the Arctic Ocean. All observations of Arctic warming can be accounted for as consequences of these flows of warm water to the Arctic. This explains why all attempts to model Arctic warming have failed: models set up for greenhouse warming are the wrong models for non-greenhouse warming. It turns out that satellites which have been measuring global temperature for the last 31 years cannot see any sign of current warming that supposedly started in the late seventies. This absence of warming in the satellite record is in accord with the observations of Ferenc Miskolczi on IR absorption by the atmosphere. What warming satellites do see is only a short spurt that began with the super El Nino of 1998, raised global temperature by a third of a degree in four years, and then stopped. It was of oceanic origin.

Citation: Energy and Environment. vol 22, pp 1069-1083. Link to full paper [Arno Arrak]

JC comment. What is going on with the Arctic climate is not straightforward to understand. Recent attribution studies (see previous Climate Etc threads) have argued that the warming in recent decades, along with the sea ice decrease, is approximately half natural, half anthropogenic. The study by Carton et al. is a very nice analysis IMO, I wish such an analysis could be done for the entire basin and back to 1900. The challenge is to sort out the following:

Solar and volcanic impacts
Ocean heat transport
Arctic teleconnection regimes (e.g. AO)
Aerosol and GHG effects
Feedbacks initiated by all of the above

It seems that you need to go back at least to 1900 to sort this out in the Arctic. What is going on with sea ice does not follow in lock step what is going on with surface temperature.

Note: While I think the Cohen et al. and Arrak papers each raise interesting points, I do not agree with either paper in their entire attribution analysis.

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