Maniplulated Climate Data?, page-23

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    so here is what the daily caller et al have got wrong, and why

    the paper the daily caller article discusses is available in full here
    http://www.sciencemag.org/content/early/2015/06/05/science.aaa5632.full

    the paper refers to a second paper that describes the approach used to adjust the ship based sea surface temps relative to the buoy temperatures; that second paper is available in full here
    http://onlinelibrary.wiley.com/doi/10.1029/2010JD015220/full

    and in the second paper refers to an earlier paper that described the problem and why it needed to be addressed
    http://journals.ametsoc.org/doi/full/10.1175/2007JCLI2100.1

    here is what that last paper says
    "The most important additional data bias may be the ship–buoy bias (Kent and Taylor 2006; Rayner et al. 2006). This relative bias is important because of the growing number of buoy SSTs since the mid-1980s (e.g., Reynolds et al. 2002). Before 1985 most in situ SSTs are ship measurements. Where both ship and buoy observations are available, the ships are typically about 0.1°C warmer. However, the bias is not constant in either space or time where both data types are available. In addition, before the mid-1980s there are few buoy observations so directly analyzing the bias from data over the full reconstruction period is not possible.
    Because ships tend to be biased warm relative to buoys and because of the increase in the number of buoys and the decrease in the number of ships, the merged in situ data without bias adjustment can have a cool bias relative to data with no ship–buoy bias. As buoys become more important to the in situ record, that bias can increase. Since the 1980s the SST in most areas has been warming. The increasing negative bias due to the increase in buoys tends to reduce this recent warming. This change in observations makes the in situ temperatures up to about 0.1°C cooler than they would be without bias. At present, methods for removing the ship–buoy bias are being developed and tested."

    So the adjustment and need for it is simple and yet totally misunderstood/misrepresented by the daily caller, Lindzen, the Cato Institute et al

    if you have ship based measurements that are consistently biased (which the papers discuss has been shown to be the case), it does not matter; a long series of ship measurements will still show the correct warming trend.  It will just be that the readings will be consistently biased low relative to satellite or buoy readings.

    Similarly if you have a long series of buoy readings, you would see a consistent trend from them

    The problem arises because we have a mix of both, and because we have increasingly more buoy readings, relative to ship readings, with more and more buoys being put in place.  As the ratio of buoy to ship readings changes, and because your overall record is a combination of both, the trend is distorted by the changing ratio of ship to buoy measurements.  You therefore need to adjust for that.  The daily caller, Lindzen and the Cato institute have totally misunderstood this.

    Yet again, an apparently interesting denial argument, but shown to be totally wrong.
    Last edited by mjp2: 06/06/15
 
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