Atmospheric temperature* | 2 - very high | Cloud sensitive.. Inaccurate in low troposphere.. Along-track only. | TIR spectrometry in the 15 micrometer band |
Cloud cover | 5 - marginal | Discontinuous coverage.. Along-track only. | TIR channel(s) |
Cloud top height | 2 - very high | Discontinuous coverage.. Along-track only. | MWIR and TIR spectrometry in window and water vapour band (for emissivity) to estimate cloud top height from its temperature |
Cloud top temperature | 1 - primary | Discontinuous coverage.. Along-track only. | TIR spectrometry in window and water vapour band (for emissivity) |
Downward long-wave irradiance at Earth surface | 2 - very high | Cloud sensitive.. Highly indirect.. Along-track only. | MWIR and TIR spectrometry including water vapour and CO2 bands |
Land surface temperature | 4 - fair | Cloud sensitive.. Coarse spatial resolution.. Along-track only. | TIR spectrometry (inclusive of several narrow-bandwidth windows and absorption bands for atmospheric corrections) |
Long-wave Earth surface emissivity | 2 - very high | Cloud sensitive.. Long time series needed.. Along-track only. | MWIR and TIR spectrometry measuring land temperature in many windows. Emissivity inferred by statistical analysis |
Sea surface temperature* | 3 - high | Cloud sensitive.. Along-track only. | TIR spectrometry (inclusive of several narrow-bandwidth windows and absorption bands for atmospheric corrections) |
Specific humidity* | 2 - very high | Cloud sensitive.. Along-track only. | TIR and FIR spectrometry in bands around 6.3 and 18 micrometers |
Integrated Water Vapour (IWV)* | 1 - primary | Cloud sensitive.. Along-track only. | TIR and FIR spectrometry in bands around 6.3 and 18 micrometers |
Upward long-wave irradiance at TOA* | 3 - high | Spectral interpolation needed.. Along-track only. | TIR and FIR spectrometry in the 11 micrometers window region, and in water vapour and CO2 bands around 6.3, 15 and 18 micrometers |
Upward long-wave irradiance at Earth surface | 2 - very high | Cloud sensitive.. Highly indirect.. Along-track only. | TIR spectrometry covering the 11 micrometers window region and the water vapour and CO2 bands around 6.3 and 15 micrometers |