A New Variational Assimilation Method Based on Gradient Information from Satellite Data

Table 2

Schemes of numerical test.

Test grouping	Initial field	Whether to add AIRS data systematic bias (+1 K)	Whether it is based on the gradient information assimilation method
CTRL	NCEP	No	No
AIRS	NCEP + AIRS	No	No
AIRS_GRD	NCEP + AIRS	No	Yes
AIRS_SYB	NCEP + AIRS	Yes	No
AIRS_SYB_GRD	NCEP + AIRS	Yes	Yes