Application of MM5-CAMx-PSAT Modeling Approach for Investigating Emission Source Contribution to Atmospheric SO_𝟐 Pollution in Tangshan, Northern China

Table 3

Wind speed and calm wind frequency in Tangshan in 2006.

Area	Month	Wind speed (m/s)	Calm frequency (%)
	January	1.49	5.71
	April	2.61	3.00
Zunhua	July	1.66	4.12
	October	1.43	11.07
	Annual	1.80	6.01
Tangshan urban	January	1.91	1.22
	April	2.63	0.43
	July	1.91	0.82
	October	1.77	7.79
	Annual	2.06	2.59
	January	2.09	3.67
	April	3.03	2.14
Leting	July	2.08	1.23
	October	1.86	4.51
	Annual	2.27	2.90