Global Sea Ice Emissivity

Development Near real time product

The sea ice surface emissivity is representative for the near 50 GHz channels used for temperature sounding of the atmosphere using satellite radiometers such as SSMIS and AMSU. The model for computing the emissivities is described in the ATBD. It uses the brightness temperatures at 19v, 37v and 37h measured by the conically scanning SSMIS.

Acronym : GBL SIEM
Product navigator reference :


OSI SAF producer : Danish Meteorological Institute
Identifier : OSI-404-b
Acronym for EDC (APNM) : OSIEMGB
Citation : See at bottom
Processing level : L3
Satellite input : DMSP/SSMIS
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 (NetCDF3), EDC (NetCDF3), EUMETCast (NetCDF3)
Characteristics & methods : Sea ice emissivity at 50GHz, daily average.
Simulated with measured coefficients.
Including uncertainties.
Data Access

OSI SAF FTP server (last 31 days)

Directory: ice/emis/

OSI SAF FTP server (archive)

Directory: ice/emis/

EUMETSAT Multicast

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.
Expected date for operational/released :
Full series temporal coverage : 2018-onwards
Detailed history :
  • Version OSI-404 until 09/08/2018
  • Version OSI-404-a since 09/08/2018: improvement is the inclusion of uncertainties.
  • Version OSI-404-b to become operational in 2024: addition of horizontally polarized emissivity and fixing issues such as the missing effective temperature
Citation : OSI SAF Global Sea Ice Emissivity, OSI-404-b. EUMETSAT Ocean and Sea Ice Satellite Application Facility. Data extracted from [distributor/distribution mean]: ([extracted period],) ([extracted domains],) accessed [download date]

The content within square brackets "[…]" is to be replaced with whatever distributor, period, domain or download date is relevant to the data being used. The "extracted period" and "extracted domains" are only needed if a subset of the data is being used.
Suggestions for "distributor/distribution mean": OSI SAF FTP server/the EUMETSAT Data Centre/EUMETCast/name and URL of a redistributor...
  • Compared to the superseded version of the Global Sea-ice Emissivity (OSI-404-a) containing only vertically polarized emissivity at 50 GHz and non-valid values for the effective temperature, this updated products (OSI-404-b) includes the addition of horizontally polarized emissivity and fixing issues such as the missing effective temperature.

    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.

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