Table 2.

Adjusted Regression Statistics for Comparisons of Predicted Surface PM_2.5 Concentrations to Measured Surface PM_2.5 Concentrations by Day^a

Date	R 2	Slope	Slope Error	Constant (μg/m3)	Constant Error μg/m3)	Number of Surface Sites > 50 μg/m3	MOD04 R2
6/24/2008	0.527	0.32	0.07	61	9	24	0.335
6/25/2008	0.236	0.18	0.07	73	9	22	0.096
6/26/2008	0.133	0.21	0.10	74	15	22	0
6/27/2008	0.536	0.74	0.14	20	15	23	0.328
6/28/2008	0.022	0.17	0.14	30	7	3	0.001
6/29/2008	0.344	0.45	0.13	16	5	1	0.183
6/30/2008	0.072	−0.27	0.17	17	3	1	0
7/1/2008	0.226	0.61	0.22	6	8	3	0.275
7/2/2008	0.07	0.20	0.12	28	8	5	0.465
7/3/2008	0.009	−0.10	0.09	12	2	0	0.069
7/4/2008	0.165	0.21	0.10	7	1	0	0
7/5/2008	0.391	0.42	0.11	14	3	2	0.579
7/6/2008	0.26	0.43	0.14	20	7	8	0.396
7/7/2008	0.346	0.59	0.16	15	8	8	0.466
7/8/2008	0.048	−0.10	0.06	45	6	10	0.064
7/9/2008	0.772	0.65	0.08	30	7	12	0.271
7/10/2008	0.674	0.58	0.09	39	12	17	0.337
7/11/2008	0.018	0.04	0.04	25	7	4	0.083
7/12/2008	0.019	0.15	0.13	20	4	1	0
7/13/2008	0	0.12	0.13	20	3	1	0.406
7/14/2008	0	0.00	0.25	21	7	1	0.075
7/15/2008	0	−0.07	0.11	20	2	0	0.029
7/16/2008	0.013	0.13	0.11	17	3	0	0
7/17/2008	0.14	0.40	0.18	9	5	0	0.237
7/18/2008	0.135	0.23	0.11	19	4	2	0.191
7/19/2008	0.558	0.64	0.12	11	4	3	0.679
7/20/2008	0	0.10	0.22	13	5	0	0
7/21/2008	0	−0.09	0.11	11	2	0	0
7/22/2008	0	0.00	0.05	16	2	0	0
7/23/2008	0.74	0.86	0.11	1	7	3	0.623
7/24/2008	0.655	0.75	0.11	7	4	3	0.401
7/25/2008	0.76	0.71	0.08	16	6	6	0.477
7/26/2008	0.83	0.90	0.08	2	4	5	0.766
7/27/2008	0.068	0.21	0.12	7	3	1	0.185
7/28/2008	0	−0.08	0.17	12	2	1	0.005
7/29/2008	0.081	0.14	0.08	9	1	0	0.097
7/30/2008	0	0.29	0.32	10	5	1	0.401
7/31/2008	0.05	0.14	0.09	11	2	0	0

^aR² Values are also shown for the same regression statistics using the MOD04 collection 5 AOD product. Comparisons are between average midday AOD-predicted PM_2.5 concentrations and 10:00 A.M. to 2:00 P.M. LST average surface PM_2.5 concentrations.