The Impact of Length-Scale Variation When Diagnosing the Standard Deviations of Background Error in a 4D-Var System and Filtering Method Investigation

Figure 1

The vorticity standard deviation field at 1000 hPa estimated from (a) 10 samples, (b) 50 samples, (c) 100 samples, (d) 200 samples, (e) 1000 samples, and (f) 10000 samples.

(a)

(b)

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(e)

(f)