Table 1.

Abundances of gases in NPSV and SPSV at 1 mbar (ppbv) compared to the expected ratio from a photochemical model¹⁹ for the same season

Gas	NPSV	SPSV	Ratio (N/S)	Model ratio
Acetylene C2H2	225 ± 65	423 ± 132	0.53 ± 0.23	1.04
Ethane C2H6	8000 ± 1841	8214 ± 4585	0.97 ± 0.58	0.98
Methyl acetylene C3H4	2.0 ± 0.2	3.3 ± 0.5	0.62 ± 0.11	0.91
Propane C3H8	100 ± 16	147 ± 20	0.68 ± 0.14	0.96
Diacetylene C4H2	0.11 ± 0.03	0.53 ± 0.07	0.20 ± 0.06	1.10
Benzene C6H6	0.26 ± 0.10	0.33 ± 0.14	0.80 ± 0.45	0.95
Carbon dioxide CO2	0.2 ± 0.1	0.5 ± 0.2	0.37 ± 0.26	1.02

With the exception of ethane and acetylene, these values were derived by scaling the a priori profiles from Moses et al.¹⁹