Post on 11-Jul-2020
R = Difference IR12.0 - IR10.8G = Difference IR10.8 - IR3.9B = Channel IR10.8
Fog / Low Clouds RGB Product("Night Microphysical")
Applications:Applications: Cloud Analysis, Fog, ContrailsArea:Area: Full MSG Viewing AreaTime:Time: Night-Time
RangesRanges and and Enhancements:Enhancements:
Beam Channel Range Gamma
Red IR12.0 - IR10.8 -4 … +2 K 1.0Green IR10.8 - IR3.9 0 … +10 K 1.0Blue IR10.8 +243 … +293 K 1.0
Fog / Low Clouds RGB Product("Night Microphysical")
Red Cloud depth, approximated by BrightnessTemperature Difference between 12.0µmand 10.8 µm.
Green Cloud phase and droplet size, approximatedby Brightness Temperature Differencebetween 10.8µm and 3.9µm.
Blue Temperature of cloud tops and surface,provided by Brightness Temperature at10.8µm.
Physical Interpretation for Clouds
Interpretation of Coloursfor High-level Clouds
Cold, thick, high-level cloud Very cold (< -50°C), thick,high-level cloud
Thin Cirrus cloud
Ocean Land
Interpretation of Coloursfor Mid/Low-level Clouds
Thick, mid-level cloud Thin, mid-level cloud
Ocean Land
Low-level cloud(cold atmosphere, Europe)
Low-level cloud(warm atmosphere, Africa)
10 - 09
09 - 04
09
In RGB 10-09,09-04,09 images, night-time fogappears in light greenish colours !
The RGB values shown above (in the red box) correspond tothe location (shown by an arrow) on the next slide !
Example 1: Fog / Low stratus
Example 1: Fog / Low stratus
MSG-1, 14 March 2005, 00:00 UTC
Fog and/or low stratus over Kazakhstan
Example 2: Cb Clouds
10 - 09
09 - 04
09
In RGB 10-09,09-04,09 images, thick Cb clouds at night appearin yellow-red colour (noise in channel IR3.9)!
The RGB values shown above (in the red box) correspond tothe location (shown by an arrow) on the next slide !
MSG-1, 19 April 2005, 03:15 UTC
Example 2: Cb Clouds
Cb anvil over Sierra Leone and Liberia(speckles due to noise in IR3.9
channel at very cold temperatures)
Example 3: Cirrus Clouds
10 - 09
09 - 04
09
In RGB 10-09,09-04,09 images, thin Cirrus cloudsappear in dark bluish colours !
The RGB values shown above (in the red box) correspond tothe location (shown by an arrow) on the next slide !
MSG-1, 18 March 2005, 00:00 UTC
Example 3: Cirrus Clouds
Wide-spread thin cirrus clouds over the Atlantic
Global View
MSG-13 February 200403:00 UTC
Good depiction of cloudcover over full disc.
Note extended patches oflow stratus over theWestern Mediterranean.