The Parameters Estimation for a PM_2.5 Transport Model with the Adjoint Method

Table 2

Error statistics of twin experiments before and after assimilation.

Experiment		(µg/m^3)		(µg/m^3)		(µg/m^3)		(10^−6 µg/m^3/s)
		Before	After	Before	After	Before	After	Before	After
TE1	0.00042	31.79	0.60	25.87	0.54	6.33	1.20	—	—
TE2	0.00931	7.80	0.82	5.60	0.73	—	—	3.16	1.04
TE3	0.00043	38.45	0.74	30.46	0.68	6.33	1.26	3.16	0.81
TE4	0.00357	31.79	1.44	25.87	1.66	6.33	2.80	—	—
TE5	0.00968	7.80	0.83	7.80	0.77	—	—	3.16	1.28
TE6	0.00316	38.45	1.79	30.46	2.23	6.33	3.19	3.16	3.47

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. and are the MAEs between prescribed and inverted IC and SS, respectively.