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Weather - not climate - extremes

  1. Dec 10, 2009 #1
    It looks like Yellowstone WY beat the all time low record of 1998 for 10 December (-22 C) with a remarkable big margin: -31C. The page updates all the time so I include a screenshot.


    But of course, when it's hot then it's global warming and when it's cold then it's natural variability
  2. jcsd
  3. Dec 10, 2009 #2


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    Actually, it might be from global warming (climate change).

    Extreme weather is one of the hallmarks of global warming which is why it's often referred to as cliamte change; storms are getting bigger and that includes winter storms.

    There was an exceptionally large storm storm over North America during this time that was pulling a lot of cold air down from the Arctic.
  4. Dec 10, 2009 #3


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    Also interesting... the previously record low was in 1998 which was one of the hottest years ever on record. (1998, 2003 and 2005 are all exceptionally close to each other, and may rank differently with different global anomaly estimates.)

    Just to underline the obvious; ALL records whether high OR low are cases where you have natural variability giving a boost to the numbers. Global trends, such as the strong global warming that has been measured over recent decades, are not identified by looking at extremes, but at the trend over all values -- high, low, and in between. The trend means you will keep getting new record highs regularly, but every new record is still a case where natural variability lifts temperatures above the main trend.

    By the way; it seems that the natural variations (globally) are on the way up again, and so given the strong warming trend, we can expect a new record hottest year pretty soon. 2010 is a distinct possibility; any one of the next three years being a new all time record for the global anomaly is a good bet. And of course, there will still be local regional cold extremes, somewhere around the planet.

    Cheers -- sylas
    Last edited: Dec 10, 2009
  5. Dec 10, 2009 #4
    Do you think that there'd be any error in your estimate of the mean global surface temperature with a non-random sample of one point?

    Because November was the hottest November yet on the UAH dataset.
  6. Dec 10, 2009 #5
    Is there also an increasing trend in short term temperature fluctuations averaged over the whole Earth, like there is for the average temperature?
  7. Dec 10, 2009 #6


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    I'm not quite sure what you are asking here. I believe that in most areas winter temperatures are increasing a bit more than summer temperatures.

    Cheers -- sylas
  8. Dec 11, 2009 #7
    Suppose you take the data from all the weather stations and for each station compute the fluctuation <T^2>- <T>^2 over, say, one month and then average this over all the stations of the World. Then this is a measure of the amplitude of short term local fluctuations, but it is averaged over the World. So, you would expect that this quantity, while it gives some information about local weather, is still determined by the climate. A good enough climate model should be able to allow one to extract this quantity.
  9. Dec 11, 2009 #8
    I'm feeling short here.

    What does the notation <> mean?
  10. Dec 11, 2009 #9


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    <X> is a notation for a mean. <X^2> - <X>^2 is variance; the mean of the square minus the square of the mean.

    I believe there is some research looking at trends in temperature variance, both for models and for historical records, but it's not something I've looked at myself much. It would be easy enough to try something like this yourself, using readily available daily data from weather stations around the world.

    Cheers -- sylas
  11. Dec 17, 2009 #10
    1998 was also an El Nino year. What I have noticed is that during El Nino events, North America gets more extreme weather, especially during the winter as the jet stream tends to dip further south bringing Arctic air down over North American continent.
  12. Jan 3, 2010 #11
    Here are a few more weather data (not climate) about the year 2009

    http://www.canadaeast.com/front/article/529471 [Broken]
    http://www2.newsadvance.com/lna/news/local/article/lynchburg_breaks_84-year_cold_record/14003/ [Broken]
    http://www.omaha.com/section/news01 [Broken]
    http://network.nationalpost.com/np/blogs/posted/archive/2009/06/07/let-the-global-warming-jokes-begin-alberta-saskatchewan-get-snow-in-june.aspx [Broken]
    http://www.todaystmj4.com/news/local/49608727.html [Broken]
    http://www.ifallsdailyjournal.com/news/weather/record-setting-cold-weekend-109 [Broken]
    http://china.globaltimes.cn/society/2009-11/484504.html [Broken]
    http://www.azstarnet.com/allheadlines/317522 [Broken]

    But as noted already, El nino was there too/, also: this

    How many heat wave events were there last year?
    Last edited by a moderator: May 4, 2017
  13. Jan 3, 2010 #12

    I could do more... but I fail to see the point.

    From your editorial comments, you seem to be suggesting that record warm and record cold are interpreted differently somehow. I have seen no evidence of scientists dismissing localized cooling as cyclical and localized warming as part of a greater trend. In fact to a climate scientist, local weather is nothing more than one of ten's of thousands of data points.

    If you are suggesting otherwise, please provide some real evidence of such a bias in the scientific community. If you are suggesting that it is the media that is misrepresenting these data points, then please ask to have the thread moved to P&WA
  14. Jan 3, 2010 #13


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    I would be interested in seeing any results on this. It seems like a good way to quantify the claim on increased variability.
  15. Jan 5, 2010 #14

    Ivan Seeking

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    And that point has probably been made here [in this forum] hundreds of times. Apparently one can take on the mainstream of science while not being capable of understanding that simple point. I'm sure this is taught in the first year of college, if not in high school.
  16. Jan 5, 2010 #15
    Why all the strawmen? This is not a climate thread, look at the title. It's about weather extremes. Like these of today:

    http://www.straitstimes.com/BreakingNews/Asia/Story/STIStory_473736.html [Broken]

    The underlying objective is maybe to discuss the possible causes of there extremities. Late Marcel Leroux did extensive research into the phenomonon Mobile Polar Highs especially in relation to paleo climate. See for instance

    Leroux, M. (1993). The Mobile Polar High: a new concept explaining present mechanisms of meridional air-mass and energy exchanges and global propagation of paleoclimatic changes. Global and Planetary Change 7, 69–93.

    See also:

    http://www.pages.unibe.ch/products/specialissues/QSR2000/markgraf.pdf [Broken]

    recent research about the phenomenon in the southern hemisphere: southern hemisphere
    Last edited by a moderator: May 4, 2017
  17. Jan 5, 2010 #16
    locked pending moderation
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