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Arctic v Antarctic Temperatures

September 20, 2012
tags: ,

By Paul Homewood

 

Other commentators have pointed out recently that, while Arctic ice is at record low levels since 1979, Antarctic sea ice levels are at or close to record highs. I thought, therefore, that this might be a good time to look at satellite temperatures for the two poles.

UAH monitor temperatures from 60N to 85N in the Arctic, and 60S to 85S in the Antarctic. While not complete, these records, of course, go much closer to the poles, and in a much more comprehensive fashion, than surface temperatures do. Figure 1 shows the UAH data, which is the anomaly from the 1981-2010 baseline, as a 12 month running average. This helps to smooth out the monthly and seasonal fluctuations and make the trend much clearer to see.

 

 

image

Figure 1

 

Two things stand out:-

1) Arctic temperatures were actually in decline during the 1980’s, before falling further around 1993, presumably as a result of the Pinatubo eruption two years earlier.

2) Between 1980 and 2012, Arctic temperature anomalies have increased from –0.22C to 0.79C, an increase of 1.01C. During the same period, however, Antarctic anomalies have fallen by 0.87C.

 

 

Of course, 1980 might not be a representative place to start. What we really need to look at are the trends leading up to that year. So what do the GISS records tell us for the period leading up to 1980?

 

image

Figure 2

http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2012&month_last=8&sat=4&sst=1&type=trends&mean_gen=0112&year1=1938&year2=1980&base1=1951&base2=1980&radius=1200&pol=pol

 

Although the Antarctic has a lot of missing data for 1938, (hence the grey), the temperature changes in the Arctic are quite clear, with most of the region about a degree colder in 1980 compared to 1938. So let’s combine the two periods.

 

Degree Centigrade North Pole South Pole
Temperature Change 1938-1980 -0.75 +2.19
Temperature Change 1980-2012 +1.01 -0.87
     
Temperature Change 1938-2012 +0.26 +1.32
     

http://data.giss.nasa.gov/gistemp/tabledata_v3/ZonAnn.Ts+dSST.txt

http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt

 

Better still, we can look at the graph of GISS anomalies for the two poles between 1938 and 1980.

 

image

 

 

Conclusions?

1) Arctic temperatures are only slightly higher now than they were in the late 1930’s.

2) While temperatures have increased in the Arctic since 1980, there have been similar decreases in the Antarctic.

3) The biggest increases occurred in the Antarctic before 1980, although the amount of missing data there in the 1930’s and 1940’s must place a question mark over the accuracy of GISS data.

 

Of course, you won’t be told any of this by the BBC, Joe Romm or the rest of the Team.

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8 Comments leave one →
  1. Sparks permalink
    September 20, 2012 8:46 pm

    Reblogged this on Sparks ~Engineering and Science..

  2. Coldish permalink
    September 21, 2012 9:06 am

    Interesting work, Paul. Your results emphasise the regional character of decadal climate change. There’s also a hint of hemispheric oscillation.

  3. F. Guimaraes permalink
    September 21, 2012 5:07 pm

    Svensmark’s paper

    http://arxiv.org/abs/physics/0612145

    shows that in the last 6000 years the north and south poles have shown opposite and simultaneous trends of cooling and warming. He calls this phenomenon the “Antarctic climate anomaly” and points to exceptional albedo of Antarctic continent and absence of clouds in the region as the most plausible causes.

  4. F. Guimaraes permalink
    September 21, 2012 5:20 pm

    Another important point in this analysis (IMO) is to consider that since the 1930’s, basically from cycles C17 to C23, there was a series of very intense solar cycles, as we may have not have for many thousands of years, which is the ultimate cause for the observed warming up to the end of the last century (as your table shows from 1938 to 2012).
    If you do the analysis for the last few years you’ll probably find that both poles are cooling, specially after 2008.
    If this is correct, then if we expect from now on a long period of “normal” solar cycles, they’d bring important decrease of average temperatures not only at the poles, but everywhere.

    • September 21, 2012 5:30 pm

      Arctic temps seem to have peaked in early 2010, and have dropped by half a degree since.

      Antarctic ones also peaked around then.

  5. Doug Proctor permalink
    September 24, 2012 11:23 pm

    Eastman & Warren, Journal of Climate submission, May 2012: A 29-Year Survey of Cloud Changes from Land Stations Worldwide 1971-2009, fig. 6 pg 38, Fig 7 pg 40 and others.

    Messy, but looks like Arctic INCREASED cloud cover, while Antarctic DECREASED cloud cover. Changes are in middle clouds, mainly stratiform.

    Paper shows how simplistic it is to use one metric to describe changes that are very much regional; math gives you the overall trend, but the specifics tell you what is happening on a continental basis.

    A thought: cloud cover changes may be counter-intuitive depending on whether cooling or warming periods dominate the resultant temperature records. Both the Arctic and Antarctic have long periods of darkness in which NO solar insolation reaches the surface. Less clouds during the winter in the Antarctic promote MORE cooling, while more clouds during the winter in the Arctic cause LESS cooling. The result is that Antarctic winters are colder now while the Arctic winters are warmer.

    It has been noted by Watts et al that the US contiguous land records show that daily average temperatures have risen primarily as a result of warmer NIGHT temperatures, not day temperatures. Is that how it is at the poles?

    As the summer albedo due to snow and ice is higher than the Arctic albedo due to snow, ice and rock/vegetation, one would need to calculate the effect of a 15% +/- change in cloud cover changes as suggested in the 2012 E &W paper together with the enhanced and reduced thermal loss due to the same clouds during the winter. in order to figure out the net result.

    Bet it will be what we have seen.

    • September 25, 2012 9:39 am

      Makes sense. The effect of the sun at high latitudes is relatively small ,so consequently cloudless days will not have the warming effect they do elsewhere.

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