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

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24 hours

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Monthly Mean Diurnal Cycle Monthly Mean

Daily Meanx

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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