Table 1. Summary of Upper Tropospheric FTO3 Measurements Above North America During Summer 2006 and Summer 2004a

Site (With Abbreviation)	Dates in 2006	Number of Profiles in 2006	2006 10-11 km Median FTO3 (Standard Deviation)	2006 > 6 km Median FTO3 (Standard Deviation)	2004 10-11 km FTO3 (Standard Deviation)	2004 > 6 km FTO3 (Standard Deviation)
Barbados (BAR)	26 Jul to 30 Aug	25	50 (12)	58 (17)	NA	NA
Boulder (BOU)	26 Jul to 31 Aug	32	53 (20)	54 (18)	NA	NA
Bratt's Lake (BRA)	1-30 Aug	29	36 (33)	52 (25)	NA	NA
Huntsville (HUN)	29 Jul to 29 Aug	30	87 (17)	78 (22)	66 (24)	61 (30)
Kelowna (KEL)	2-30 Aug	27	48 (27)	50 (22)	NA	NA
Mexico City (MEX)	22 Aug to 15 Sep	21	58 (11)	57 (15)	NA	NA
Mid-Atlantic (MDA)	1-30 Aug	23	74 (17)	69 (20)	64 (31)	64 (30)
Ontario (ONT)	1-30 Aug	35	52 (24)	56 (22)	58 (24)	59 (20)
Narragansett (NAR)	27 Jul to 30 Aug	29	53 (28)	54 (23)	68 (23)	63 (25)
Sable Island (SAB)	1-31 Aug	28	71 (20)	65 (21)	56 (23)	58 (19)
Socorro (SOC)	1-25 Aug	25	63 (21)	63 (19)	NA	NA
Table Mtn (TAB)	1-31 Aug	31	35 (22)	40 (24)	48 (23)	45 (26)
Texas coast (TXC)	1-31 Aug	44	75 (20)	76 (21)	73 (12)	70 (18)
Trinidad Head (TRI)	27 Jul to 30 Aug	31	43 (23)	42 (20)	39 (23)	45 (24)

aSummer 2004 data from Cooper et al. [2006].