CM-SAF TOA radiation status report

1
CM-SAF TOA radiation status report

• D. Caprion
• Royal Meteorological Institute of Belgium

2
Overview

• Main problems since lastest meeting
• Changes to operational chains
• Status input products GERB
• Status input products CERES

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Main problems

• Hardware problems beginning of September
• Unfortunately check our backup system
• Not so bad, not so good so need of improvements
  !
• Consequences delays to deliver products
• High resolution OK now
• TOA fluxes July and August coming soon...
• Definition of the grid
• What kind of grid shall we have to use ?

4
Grid ?

• What do we want ?
• Equal-area grid with a resolution of
• either (15 km)² or (45 km)²
• Answer
• Sinusoidal grid with 2N x N pixels
• Tuning of N to get the resolution
• But does it fully answer the requirements ?

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Grid ?

• Yes And no ? Why?
• The Earth is an ellipsoid
• What
  do we need fixed pixel
  location or fixed pixel size ?
  

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Grid ?

• In other words
• What kind of implementation ?

DWD
RMIB
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Grid ?

• Consequences
• DWD
• Exact Equal-area grid but non-linear dependence
  of the latitude with the pixel index !
• RMIB
• Linear dependence of the latitude with pixel
  index but nearly Equal-area grid !
• Open questions ?

8
Grid ?

• Try and be a user
• 1. Do I really need an exact Equal-area grid in
  which geolocation is not trivial ?
• 2. Do I need an easy geolocation even if I lost
  the exact Equal-area property of my grid ?
• 3. How do I manage to pass from the low
  resolution to the high resolution grid ? If not
  implemented in the same way !

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Grid ?

• From RMIB point of view
• No definitive answer, except
• It is always easier to use
• lat 90-180y/N
• lon(x-N)180/(Ncos(lat))
• Than implement an elliptic integral needed to
  compute the fixed size of the pixels.
• The user should easily go from one grid to the
  other one !!

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Changes to operational chain

• Implementation of three parallel chains
• 1 mixed (GERB/GERB-like) chain current one
• 1 pure GERB
• 1 pure GERB-like
• test on data from May 2005 to now

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Changes to operational chain
GERB-like
GERB-like
GERB
GERB
Regridding
Regridding
Regridding

Averaging
Averaging
Averaging
Merge with CERES
Final products in HDF files
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GERB status

• Instrument currently in safe mode
• Till mid-October (eclipse seasons)
• Planned release beginning 2006
• GIST meeting end of December 2005 to give
  official approval
• Planned reprocessing as soon as possible
• Preliminary tests on June and July 2004 seems to
  be positive.

13
CERES status

• Currently used ES9, Terra, FM1, Edition 1
• Available up to August 2005
• More advanced SRBAVG
• Better angular models, better spatial resolution
• Still waiting for !
• Decision beginning of November ?

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Conclusions

• Continue to check operational chains.
• Should we change the grid ?!?
• GERB data release planned for...
• Beginning 2006
• So reprocessing.....