Licensed under CC BY 4.0 by EUMETSAT
Information
Description
Quicklook
Production status
Documentation
PUM
ATBD
SVR

Global Sea Ice Emissivity

Operational Near real time product

Gridded sea ice surface emissivity representative for the near 50 GHz channels. Two coefficients, Roughness and Scaling, are calculated from the brightness temperatures at 19v, 37v and 37h, measured by the conically scanning SSMIS, and are used to compute emissivity using an emissivity model with some typical satellite sensor configurations. The product is used for temperature sounding of the atmosphere using satellite radiometers such as SSMIS and AMSU. Users can also compute emissivity corresponding to their specific applications (e.g., polarization and incidence angle). Effective temperature, derived from AMSR2, is also provided.

Identification
Acronym : GBL SIEM
Product navigator reference :

EO:EUM:DAT:DMSP:SISE50

OSI SAF producer : Danish Meteorological Institute
Identifier : OSI-404-b
Acronym for EDC (APNM) : OSIEMGB
License/Attribution : See at bottom
Characteristics
Processing level : L3
Satellite input : DMSP/SSMIS, GCOM-W/AMSR2
Other input : None
Temporal sampling : 1 per day
Central time : 12:00
Timeliness : ? The timeliness is the time elapsing from the sensing time of the last contributing file to the product dissemination to users. It is similar to the latency. 5 h
Spatial coverage : Global
Spatial sampling : 10 km
File Formats : HL FTP Server (NetCDF4), EDC (NetCDF4), EUMETCast (NetCDF4)
Characteristics & methods : Sea ice emissivity at 50GHz, daily average.
Simulated with measured coefficients.
Including uncertainties.
Data Access

OSI SAF FTP server (last 31 days)

ftp://osisaf.met.no/prod/

Directory: ice/emis/

OSI SAF FTP server (archive)

ftp://osisaf.met.no/archive/

Directory: ice/emis/

OSI SAF Thredds

https://thredds.met.no/thredds/osisaf/osisaf.html

https://thredds.met.no/thredds/osisaf/osisaf_seaiceemis.html

EUMETSAT Multicast

EUMETCast

EUMETSAT Archive

EUMETSAT Data Centre

Direct link

Accuracy Requirements
Target accuracy : 5 %
Verification/validation method : Compare with RTM simulations using NWP
Applications and users
Usage : NWP and Ocean/Ice models, operational Met and Sea Ice services.
History
Authorised to be operational / released :
Declared operational / released since :
On EUMETCast since :
On EDC since :
On FTP server since :
First date :
Full series temporal coverage : 2018-onwards
Detailed history :
  • Version OSI-404 until 09/08/2018
  • Version OSI-404-a from 09/08/2018 to 04/03/2025: improvement is the inclusion of uncertainties.
  • Version OSI-404-b from 04/03/2025: addition of horizontally polarized emissivity and fixing issues such as the missing effective temperature
License/Attribution
License/Attribution : Licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0) by EUMETSAT.

Whether you’re displaying the product as-is or if you have used it as input data, please use one of the following attribution:

Figures (short): "EUMETSAT OSI SAF OSI-404-b"

Texts (long): “Data source: EUMETSAT OSI SAF, Global Sea Ice Emissivity (2025), OSI-404-b.”

Papers: “EUMETSAT Ocean and Sea Ice Satellite Application Facility, Global Sea Ice Emissivity (2025), OSI-404-b.”
Comments

  • The main updates for the emissivity product (compared to OSI-404-a) are :

    • a fix of the effective temperature variable (previously missing in the product),
    • inclusion of horizontally polarized emissivity (in addition to the vertically polarized emissivity),
    • separation of status flags for input and output (previously one flag),
    • all fill values are set to NaN,
    • change from NetCDF3 to NetCDF4 as output format,
    • changes in product global attributes.

    Furthermore, the product now offers users more flexibility by providing the coefficients and equations used for emissivity calculation so that they can calculate emissivity for arbitrary satellite zenith angles and polarization according to their needs.

    Please note also that OSI SAF products are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0) by EUMETSAT. See OSI SAF usage policy and acknowledgement
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