RN WW2 Observations index
SLP Diagnostics for the new marine obs
I've compared the pressure observations from the new obs with ICSLP - a monthly marine pressure anomaly dataset made from the ICOADS 2 obs. ICSLP is not a product itself, but it is a component that is used in production of
HadSLP.
Coverage
The figure below shows the improvement in coverage given by the new obs. The plot is the extra fractional coverage provided by the new obs (fraction of months during 1938 and 1941-7 (i.e. 1938-47 with 1939 and 1940 removed), for each 5x5 degree square, where there are new obs but no ICOADS obs.) The results are almost the same as for SST.
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| Fractional improvement in coverage (1938 and 1941-7). |
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For more detail, see the
month-by month comparisons.
The next figure shows the global number of observations and total fractional coverage both before and after adding the new observations.
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| Coverage and number of observations with and without the new observations. |
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Differences between new obs and ICSLP
Difference fields between ICSLP and the new observations have been calculated for
each month. The figure below is the mean of the monthly differences over 1938 and 1941-7. No bias adjustments have been applied to either dataset.
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| Mean diffs: new-ICSLP (1938 and 1941-7). |
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The next figure is a time series comparing monthly global average SLP anomaly from ICSLP and the new data.
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| Global mean from ICSLP and the new observations. |
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Global average pressure is not a very useful diagnostic - but the figure does suggest that there are no systematic biases in the new data..