1. ATMOSPHERIC TEMPERATURE SOUNDING
If radiation is selected in a sounding channel for which
and we define a function K(z) =
When the primary absorber is a well mixed gas (e.g. oxygen or CO2) with known concentration it can be seen that the measured radiance is essentially a weighted average of the atmospheric temperature profile, or
The function K(z) that defines this vertical average is known as a
WEIGHTING FUNCTION

2. CO2slicing: weighting functions
MODIS CO2 band weighting functions
CO2slicing: weighting functions
Bands w/greater CO2 absorption
have weighting functions more
sensitive to high clouds
Example spectra (~ µm)
S. Platnick, ISSAOS ‘02

3. BT in and out of clouds for MODIS CO2 bands
S. Platnick, ISSAOS ‘02

5. CO2slicing: weighting functions
MODIS CO2 band weighting functions
CO2slicing: weighting functions
Bands w/greater CO2 absorption
have weighting functions more
sensitive to high clouds
Example spectra (~ µm)
S. Platnick, ISSAOS ‘02

6. > > > > Cross section [m2] ρ5,T5,P5 ρ4,T4,P4 ρ3,T3,P3

8. CO2slicing: weighting functions
MODIS CO2 band weighting functions
CO2slicing: weighting functions
Bands w/greater CO2 absorption
have weighting functions more
sensitive to high clouds
Example spectra (~ µm)
S. Platnick, ISSAOS ‘02

10. CO2slicing: weighting functions
MODIS CO2 band weighting functions
CO2slicing: weighting functions
Bands w/greater CO2 absorption
have weighting functions more
sensitive to high clouds
Example spectra (~ µm)
S. Platnick, ISSAOS ‘02

12. CO2slicing: weighting functions
MODIS CO2 band weighting functions
CO2slicing: weighting functions
Bands w/greater CO2 absorption
have weighting functions more
sensitive to high clouds
Example spectra (~ µm)
S. Platnick, ISSAOS ‘02

14. INSTABILITY INDICES

15. MSG Lifted Index