0 0 OZONE
1 1 WATER VAPOUR
2 2 METHANE
3 3 CARBON DIOXIDE
4 4 CARBON MONOXIDE
5 5 NITROGEN DIOXIDE
6 6 NITROUS OXIDE
7 7 FORMALDEHYDE
8 8 SULPHUR DIOXIDE
9 9 VOLCANIC SULPHUR DIOXIDE
25 25 PARTICULATE MATTER < 1.0 MICRONS
26 26 PARTICULATE MATTER < 2.5 MICRONS
27 27 PARTICULATE MATTER < 10 MICRONS
28 28 AEROSOLS (GENERIC)
29 29 SMOKE (GENERIC)
30 30 CRUSTAL MATERIAL (GENERIC DUST)
31 31 VOLCANIC ASH
32 32 CLOUD
33 33 CLOUD AND AEROSOLS
255 255 MISSING VALUE
