The High Order Conservative Method for the Parameters Estimation in a PM_2.5 Transport Adjoint Model

Table 2

The MAEs statistics before and after assimilation, with 55 observation points.

Experiment	J300/	(μg/m^3)		(μg/m^3)		(10^−6 μg/m^3/s)
		Before	After	Before	After	Before	After
Cressman		30.49	0.79	6.33	1.58	3.16	1.07
PPM		30.49	0.43	6.33	1.42	3.16	1.01
PPM		30.49	0.35	6.33	1.19	3.16	0.87

is the final value of cost function and is the initial value of cost function. and are the MAEs between simulated values and observations in “assimilated cities” and “checked cities,” respectively. is the MAEs between the observations and simulated results in all the cities at the initial time.