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

Table 1

The monthly mean RMSE for 500 hPa and 850 hPa geopotential heights.

Height (hPa)	Northern hemisphere		Southern hemisphere		Tropics
	CN	SP	CN	SP	CN	SP
500	57.0029	52.8616	124.1658	116.0676	46.0208	42.6178
850	49.2861	42.1323	131.9647	124.7308	37.4340	34.2293