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    Re: The taxonomy of refraction
    From: Marcel Tschudin
    Date: 2011 Jan 9, 20:42 +0200

    John here some sources for previous meteorological data for your
    region (Chatham, MA):
    Station data (e.g. of airport):
    If you scroll down this page you may eventually find one which is even
    nearer to you. In order to find the values of a previous date scroll
    down this page and look on the left side for the title "Detailed
    History and Climate". Here you can enter the date of interest. This
    will show you all the measurements of that day made by the selected
    Atmospheric profile (sounding data):
    The soundings are made twice a day at 00Z and 12Z. Some stations do
    sometimes also two additional ones at 06Z and 18Z. The nearest one to
    you is again at Chatham. Select on the above Web-page the time period
    (date and soundings) and enter the station number 74494 or only its
    code "CHH". The measurements are then shown in a new Web-page. The
    lowest values give you some indication of the temperature gradient at
    the surface. The values for 16m corresponds to the station height.
    (Since in the lowest few tenths of meters above the surface the
    temperature profile is generally logarithmic, the estimated linear
    gradient is only a gross indication.)
    Sea Surface Temperature:
    The best I could find so far for your area is here
    http://www7320.nrlssc.navy.mil/global_nlom32/ Select here "Atlantic
    Ocean" and then "Gulf Stream Region". Open on this new page under "SST
    Nowcast" the "Snapshot archive" and select then your date. The figure
    shows your region. Since the values for the coastal areas are not
    shown, it can only give you a gross idea. There may eventually be
    better sources for SST data.
    Hopefully this helps you to find more information on the actual
    conditions of your inferior mirage photo.

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