Arctic temperature anomaly uncertainties

Dr. Roger Pielke Sr. writes of a new paper which suggest that Arctic temperaturehas even greater uncertainty problems.

He writes (excerpts)

New Paper “A Multi-Data Set Comparison Of The Vertical Structure Of Temperature Variability And Change Over The Arctic During The Past 100 Years” By Brönnimann, et al 2012

DMI Arctic temperature anomaly from WUWT Sea Ice page – click

I was alerted to a new paper on Arctic climate (h/t Erik). The paper is

Brönnimann, et al 2012 : A multi-data set comparison of the vertical structure of temperature variability and change over the Arctic during the past 100 years . Climate Dynamics (in press)

The abstract reads [highlight added]

We compare the daily, interannual, and decadal variability and trends in the thermal structure of the Arctic troposphere using eight observation-based, vertically resolved data sets, four of which have data prior to 1948. Comparisons on the daily scale between historical reanalysis data and historical upper-air observations were performed for Svalbard for the cold winters 1911/1912 and 1988/89, the warm winters 1944/1945 and 2005/2006, and the International Geophysical Year 1957/58. Excellent agreement is found at mid-tropospheric levels. Near the ground and at the tropopause level, however, systematic differences are identified.

On the interannual time scale, the correlations between all data sets are high, but there are systematic biases in terms of absolute values as well as discrepancies in the magnitude of the variability. The causes of these differences are discussed. While none of the data sets individually may be suitable for trend analysis, consistent features can be identified from analyzing all data sets together. To illustrate this, we examine trends and 20-yr averages for those regions and seasons that exhibit large sea-ice changes and have enough data for comparison. In the summertime Pacific Arctic and the autumn eastern Canadian Arctic, the lower tropospheric temperature anomalies for the recent two decades are higher than in any previous 20-yr period. In contrast, mid-tropospheric temperatures of the European Arctic in the wintertime of the 1920s and 1930s may have reached values as high as those of the late 20th and early 21st centuries.

From the paper:

These large discrepancies among the data sets underscore the large uncertainties involved with estimates of the trend.

Read the rest of Dr. Pielke’s comments here

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16 thoughts on “Arctic temperature anomaly uncertainties

  1. The New York Times headlines have 128 years of looming polar doom as seen below from their newspaper:

    1881: “This past Winter, both inside and outside the Arctic circle, appears to have been unusually mild. The ice is very light and rapidly melting …”

    1932: “NEXT GREAT DELUGE FORECAST BY SCIENCE; Melting Polar Ice Caps to Raise the Level of Seas and Flood the Continents”

    1934: “New Evidence Supports Geology’s View That the Arctic Is Growing Warmer”

    1937: “Continued warm weather at the Pole, melting snow and ice.”

    1954: “The particular point of inquiry concerns whether the ice is melting at such a rate as to imperil low-lying coastal areas through raising the level of the sea in the near future.”

    1957: “U.S. Arctic Station Melting”

    1958: “At present, the Arctic ice pack is melting away fast. Some estimates say that it is 40 per cent thinner and 12 per cent smaller than it was fifteen years [ago].”

    1959: “Will the Arctic Ocean soon be free of ice?”

    1971: “STUDY SAYS MAN ALTERS CLIMATE; U.N. Report Links Melting of Polar Ice to His Activities”

    1979: “A puzzling haze over the Arctic ice packs has been identified as a byproduct of air pollution, a finding that may support predictions of a disastrous melting of the earth’s ice caps.”

    1982: “Because of global heating attributed to an increase in atmospheric carbon dioxide from fuel burning, about 20,000 cubic miles of polar ice has melted in the past 40 years, apparently contributing to a rise in sea levels …”

    1999: “Evidence continues to accumulate that the frozen world of the Arctic and sub-Arctic is thawing.”

    2000: “The North Pole is melting. The thick ice that has for ages covered the Arctic Ocean at the pole has turned to water, recent visitors there reported yesterday.”

    2002: “The melting of Greenland glaciers and Arctic Ocean sea ice this past summer reached levels not seen in decades, scientists reported today.”

    2004: “There is an awful lot of Arctic and glacial ice melting.”

    2005: “Another melancholy gathering of climate scientists presented evidence this month that the Antarctic ice shelf is melting – a prospect difficult to imagine a decade ago.”

  2. This will be a most interesting paper to go over carefully. It would appear that the thinness of the data sets combined with a less then complete understanding of interactions and atmospheric processes in the Arctic are showing a complex, low frequency, fluctuation. If that can be extrapolated to something like a predictive model remains to be seen.

  3. That paper is informative and will take a long time for me (and I suspect most readers) to absorb.

  4. Considering what has been done in the name of ‘science’ over the past 30 years, it would be appropriate to reconsider all scientific claims as to the validity of any findings. That would include any claimed hazards regarding mercury, DDT, freon, and many other issues that have effected public policy. And yes, that would also include the use of recreational drugs.

    We, the public, have been misled in too many ways and reviews of the past ‘science’ need to be taken. A case in point would clearly be the CAGW issue.

  5. Basically, what the study is doing is looking at several different reanalysis (one apparently pure observational for the upper air) data sets to examine long term surface and atmospheric temperature trends. Apparently they all disagree on important features and all have problems. But it doesn’t sound like any of them are reliable enough to allow us to accurately gauge the size of recent climate trends in the Arctic atmosphere…assuming they are all equally valid and that it’s not the case that one of them is better than all the others, that is. Nevertheless they do provide an interesting opportunity to test climate model output. With regret, however, I predict this, if done, will lead the conclusion that whichever dataset disagrees the least with the models is the most “correct” one. Work will then be done to “correct” the others to agree with which ever dataset that is, which will itself probably be “corrected” to agree better with the models.

    This isn’t a conspiracy theory, it’s the entire history of climate science(tm)’s approach to atmospheric temperature data.

  6. Concerning the vertical structure, almost all recent warming trends (1978-1997 and 1988-2007),with the most notable exception of the summer trend in the Pacific Arctic, are stronger near the ground than at 700 hPa.

    Increased solar insolation. The Pacific Arctic exception will be due to aerosols originating in China.

  7. In the DMI temperature anomaly graph (seems like an error-it is not an anomaly, but rather the actual temp in K) I see a feature I have noted before.

    We have the green line-climate average, and the red actual temps for this year. [as I interpret the graph]
    Why are the actual temps at the right of the graph (noisy red line) for the early part of the year mostly (by eye ball) about 6 degrees warmer than the climate record (30 years of data averaged?).

    Warming?

  8. Steven Kopits says:
    June 6, 2012 at 12:22 pm

    Albertalad comment should be elevated to post.
    _________________________
    I will Second that request.
    It would make a great double sided T-shirt too.

  9. Jay says: “Why are the actual temps at the right of the graph (noisy red line) for the early part of the year mostly (by eye ball) about 6 degrees warmer than the climate record (30 years of data averaged?).”

    Lindzen has mentioned before in several talks this feature where the winter daily temperatures are highly variable. I wouldn’t put too much stock into a single year’s early winter being persistently above average. Apparently those spikes are related to cyclones of mid-latitude origin that penetrate the Arctic circle.

    (a note: some of you in the Southern Hemisphere may be used to the term “cyclone” referring specifically to Tropical Cyclones (here in the US ours are called Hurricanes or Tropical Storms if they aren’t strong enough, in much of Asia they call theirs Typhoons. In this case “midlatitude cyclone” refers to a low pressure storm system, which is not Tropical in nature.)

    Anyway, you’ll notice that the summer temperatures vary much less. It is the summer temperatures which depend pretty much exclusively on the local radiation balance.

  10. BTW, if you use the NCEP/NCAR reanalysis two meter dailies for the same region as the DMI record (DMI is mostly ERA-40 until recently, IIRC, so comparable) the trend in annual summer maxima is negligible (about .02 Kelvin per decade) since 1948. By contrast the winter minima temperatures trend a whole Kelvin per decade. The annual mean is a little less than half a Kelvin linear trend per decade. In other words, according to the reanalysis data, the highest temperatures in the Arctic are basically static, the warming is concentrated in the winter, when temperatures are well below freezing and will continue to be for some time.

  11. Plugs and fudges that exploit data inadequacy and uncertainty are the meat and drink of (C)AGW theory.

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