Introduction into the Absorption Channels

1
Introduction into the Absorption Channels

• Description of characteristics and content of the
  CO2 channelCh11 13.4 ?

Contact person Veronika Zwatz-Meise zwatz-meise_at_z
amg.ac.at Version 1.0. 13 July 2004
2
All MSG channels

• Channel 01 VIS 0.6 ?
• Channel 02 VIS 0.8 ?
• Channel 03 NIR 1.6 ?
• Channel 04 MIR 3.9 ?
• Channel 05 WV 6.2 ?
• Channel 06 WV 7.3 ?
• Channel 07 IR 8.7 ?
• Channel 08 IR 9.7 ? (Ozon)
• Channel 09 IR 10.8 ?
• Channel 10 IR 12.0 ?
• Channel 11 IR 13.4 ? (CO2)
• Chanell 12 HRV (High Resolution Visible)

3
CO2 channelCh11 13.4 ?m
4
Ch11 13.4 ?
Sun radiation Earth radiation
Watt/ m2 and micron
Ozone
Carbon dioxid
Water vapour
Wavelength (micron)
5
Comparison of radiation sources sun - earth

• For wave length lt 5 ?m solar radiation is
  dominant
• For wave length gt 5 ?m radiation of earth is
  dominant

• Ch01, 02, 03, 12 only sun radiation
  
• Ch04 both radiation from sun and earth
• Ch 05, 06, 07, 08, 09, 10, 11 only thermal
  earth radiation

Sun radiation Earth radiation
Watt/ m2 and micron
only VIS
VIS IR
only IR
6
Energy spectrum SourceEUMETSAT
Ch11

• Ch11 is in the wing of the CO2 absorption band
  around 15 ?m

7
Maximal signal from around 870 hPa
Weighting functions SourceEUMETSAT
8
Maximal signal from around 820 hPa
Weighting functions SourceEUMETSAT
Figure 3d
9
Application areas for the CO2 channel

• Qualitative application of images
• No additional features compared to the IR window
  channels
• No special application for qualitative image
  interpretation (at the time being)
• Quantitative applications
• temperature profiles
• instability
• winds

10
Ch1113.4
11
Ch0910.8
12
Ch1012.0