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

Figure 4

Temperature standard deviation field at 500 hPa (a) at 1200 UTC, (b) at 2400 UTC, and (c) and (d) as the former but at 1000 hPa.

(a)

(b)

(c)

(d)