High Latitude Sea and Ice Surface Temperature

Northern High Latitude L3 Sea and Sea Ice Surface Temperature

Operational Near real time product

NRT 12 hourly aggregated SST and IST product for northern high latitudes (Poleward of 50N). It is based on AVHRR data.

Acronym : NHL L3 SST/IST
Product navigator reference :


OSI SAF producer : Norwegian Meteorological Institute
Identifier : OSI-203-a
Acronym for EDC (APNM) : OSSTIST3A
Processing level : L3
Satellite input : Metop-B/AVHRR
Other input : ECMWF outputs
Frequency : 2 per day
Central time : 00:00, 12:00
Timeliness : 3h30
Spatial coverage : Poleward of 50N
Spatial sampling : 5 km
Projection : polar stereographic
File Formats : HL FTP Server (NetCDF4), EDC (NetCDF4), EUMETCast (NetCDF4)
Characteristics & methods : SST : subskin temperature. Multispectral algorithms
IST : skin temperature. Multispectral algorithms.
Probabilities of open water and sea ice. Single sensor analysis.
Data Access
Main Diffusion Means : HL FTP server, last 31 days (hosted by MET Norway) : ftp://osisaf.met.no/prod/sst/l3c/
Archive HL FTP server : ftp://osisaf.met.no/archive/sst/l3c/
Other means :


Accuracy Requirements
Target accuracy : SST bias: 0.7 K SST std: 1.0 K; IST bias: 1.5 / 3.5 K IST std: 2.0 / 3.0 K; PoD: 0.80 FAR: 0.20
Verification/validation method : SST : comparison with buoy measurements; IST: Comparison with buoy measurements on the ice, and IR radiometer when available; Comparison with high resolution manual ice charts
Applications and users
Usage : * Operational Met Services
* Operational analyses and ocean models
* Research or Environmental monitoring.
Authorised to be operational / released :
Declared operational / released since :
On EUMETCast since :
On EDC since :
On FTP server since :
First date :
  • Monthly accuracies.
    Include sea ice surface temperature and Sea Ice Probabilities.
    The IST accuracy requirements are split in two: the first is for validation against in situ IR radiometers, the second for in situ buoy data. The reason for this is discussed in the ATBD for OSI-205.

    Superseds OSI-203 from 03/04/2019, together with OSI-203-a.

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