presentation of the monthly mean cm-saf products didier caprion rmib
TRANSCRIPT
Presentation of the monthly mean CM-SAF products
Didier Caprion
RMIB
Averages within the RMIB CM-SAF machine
Designed and built by: B Nicalu, N. Clerbaux, S. Dewitte and D. Caprion
Overview:
• What do we want ?
• What do we have ?
• Spatial integration of CERES and GERB data (« regridding »)
• Time integration of GERB data
• Building final averages of GERB data
• Merging of CERES and GERB data
• What’s left to do ?
What do we want ?
Monthly Mean, Daily Mean and Monthly Mean Diurnal Cycleof the TOA flux radiations for:
Incoming Solar Flux (TIS) Emitted Thermal Flux (TET) Reflected Solar Flux (TRS)
(images from http://www.dwd.de/en/FundE/Klima/KLIS/int/CM-SAF/products/index.htm)
What do we have ?
TIS: pre-existing Total Solar Irradiance measurements
TRS/TET: CERES (ES9 data):
Polar satellite – data already averaged
GERB:Geostationary over Europe + AfricaData every 15 minutes
… …
(10th March 2004 - TRS)
14:15 14:30 14:45
Monthly mean March 2004 (TRS)
Overview:
• What do we want ?
• What do we have ?
• Spatial integration of CERES and GERB data (« regridding »)
• Time integration of GERB data
• Building final averages of GERB data
• Merging of CERES and GERB data
• What’s left to do ?
Spatial integration of CERES and GERB
Size 445 x 890 pixels - resolution: 45.03 km
CERES GERB GERB-like
(if GERB data are missing)
Overview:
• What do we want ?
• What do we have ?
• Spatial integration of CERES and GERB data (« regridding »)
• Time integration of GERB data
• Building final averages of GERB data
• Merging of CERES and GERB data
• What’s left to do ?
Time integration of GERB dataTRS: 10th March 2004
13:45 14:00 14:3014:15 15:0014:45
offset: acquisition timedifferent for each line
Average through integration
measured
extrapolated
14:00
Time integration of GERB data what does it imply ?
Weighted average
Central points always contribute to ¼
Extreme points contribute according to offset (o) and interval time ()
e.g. when offset is equal to zero :First and last points contribute to 1/8, all others to 1/4
Time integration of GERB data case of missing data
No data within the interval
No data in output
Just one data within the interval
Final value is a copy of this unique data
More than one data within the interval
integration
Overview:
• What do we want ?
• What do we have ?
• Spatial integration of CERES and GERB data (« regridding »)
• Time integration of GERB data
• Building final averages of GERB data
• Merging of CERES and GERB data
• What’s left to do ?
Building final averages
x
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x x
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x x
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30/3
1 da
ys
24 hours
x x
x
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x x
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x x
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x
Monthly Mean Diurnal Cycle Monthly Mean
Daily Meanx
x
x
x
Overview:
• What do we want ?
• What do we have ?
• Spatial integration of CERES and GERB data (« regridding »)
• Time integration of GERB data
• Building final averages of GERB data
• Merging of CERES and GERB data
• What’s left to do ?
Merging of CERES and GERB data
+
=
CERES GERB
Applying mask
What’s left to do ?
Launch the CM-SAF machine (operational service)
Switch from CERES ES9 data to SRBAVG data(better resolution)
Quantify the errors due to the missing data strategy- substitution by the GERB-like data- (better GERB-like data ?)- integration scheme with few data