Atmospheric temperature | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. |
C2H2* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. C2H2 lines around 7.5 and 13.7 micrometers. |
C2H6* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. C2H6 lines around 3.3 and 12 micrometers. |
CFC-11* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. CFC-11 lines around 9.2 and 11.7 micrometers. |
CFC-12* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. CFC-12 lines around 8.8 and 10.8 micrometers. |
HCFC-22* | 2 - very high | Limited to high atmosphere. | TIR spectrometry. HCFC-22 lines around 7.6, 9.0 and 12.3 micrometers |
CH4 mole fraction* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. CH4 lines around 4.3 and 7.7 micrometers. |
ClONO2* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. ClONO2 lines around 5.7, 7.7 and 12.5 micrometers. |
CO* | 4 - fair | Limited to high atmosphere. | MWIR spectrometry. CO lines around 4.6 micrometers. |
CO2 mole fraction* | 2 - very high | Limited to high atmosphere. | MWIR and TIR spectrometry. CO2 lines around 4.3 and 15 micrometers. Limb sounding mechanical or electronical |
COS* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. COS lines around 4.8 and 11.6 micrometers. |
H2O* | 4 - fair | Limited to high atmosphere. | MWIR/TIR spectrometry in a range centred on 6.3 micrometers. |
HNO3* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. HNO3 lines around 5.9, 7.6 and 11.3 micrometers. |
N2O mole fraction* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. N2O lines around 4.5 and 7.7 micrometers. |
N2O5 | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. N2O5 lines around 5.8 and 8 micrometers. |
NO* | 4 - fair | Limited to high atmosphere. | MWIR spectrometry. NO lines around 5.3 micrometers. |
NO2* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. NO2 lines around 6.1 micrometers. |
O3* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. Ozone band around 9.7 micrometers. |
PAN* | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. PAN lines around 5.7, 8.6 and 12.5 micrometers. |
PSC occurrence | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry. Limb sounding mechanically or electronically |
SF6* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. SF6 lines around 10.5 micrometers. |
SO2* | 4 - fair | Limited to high atmosphere. | TIR spectrometry. SO2 lines around 7.3 and 8.6 micrometers. |
Specific humidity | 4 - fair | Limited to high atmosphere. | MWIR and TIR spectrometry in the water vapour band around 6.3 micrometers |