Meteosat Indian Ocean Downward Longwave Irradiance

Demonstrational Near real time product

Estimation of the downward longwave irradiance reaching the Earth surface derived from SEVIRI data on board the geostationary satellite Meteosat. Algorithm is a bulk parametrization that uses NWP model outputs to calculate a clear sky Downward Longwave Irradiance (DLI), corrected according to satellite derived cloud information. The hourly product is interpolated at rounded UT hours, by a pixel dependant temporal interpolation between two consecutive satellite images. The value in the daily product is the integration of all the hourly values in the UT day. The product is remapped onto a 0.05° regular grid and expressed in W/m2.

Acronym : MET IO DLI
OSI SAF producer : Météo-France
Identifier : OSI-IO-DLI
Processing level : L3
Satellite input : Meteosat-8/SEVIRI
Other input : ECMWF outputs (temperature, humidity and aerosols profiles)
Frequency : 24 per day + 1 per day
Timeliness : 2 h
Spatial coverage : East Atlantic, West Indian: 60N-60S 18.5W-101.5E
Spatial sampling : 0.05° Lat-Lon
File Formats : LML FTP Server (NetCDF4)
Characteristics & methods : bulk parametrization
Data Access
Main Diffusion Means : LML FTP server (hosted by Ifremer) :
backup LML FTP server (last 7 days) :
Other means :


Accuracy Requirements
Target accuracy : monthly (TBC) relative absolute mean difference: 5%, monthly relative standard deviation :10%
Verification/validation method : routine comparison with pyrgeometer measurements
Applications and users
Usage : Ocean atmosphere studies.
Authorised to be operational / released :
On FTP server since :
First date :
  • From 19/01/2021, processed with a new chain, using cloud products from NWC SAF software v2018

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