For complementing its Central Facilities capability in Darmstadt and taking more
benefit from specialized expertise in Member States, EUMETSAT created
Satellite Application Facilities (SAFs), based on co-operation between several
institutes and hosted by a National Meteorological Service.
The Ocean and Sea Ice Satellite Application Facility (OSI SAF) is an answer
to the common requirements of meteorology and oceanography for a comprehensive
information on the ocean-atmosphere interface.
One of the objectives of the OSI SAF is to produce, control and distribute
operationally in near real-time OSI SAF products using available satellite
data with the necessary Users Support activities.
1 - IMPORTANT OCEANIC FEATURES AND REQUIREMENTS FOR SATELLITE DATA
The research in oceanography, the monitoring of climate and coastal environment, the operational marine meteorology,
the Navy operations and the off-shore activities have a common need to observe, describe, analyse and forecast the state of the oceans and its variations.
In this respect, the measurement of oceanic physical parameters (temperature, salinity and currents), as well as momentum, energy and fresh water exchanges
at the ocean/atmosphere interface which drive their evolution, is of extreme importance.
Because of its physical nature, the ocean is much more difficult to observe than the atmosphere :
most of the significant phenomena have a characteristic size which is one order of magnitude smaller than their equivalent in the atmosphere,
and most of the signals are weaker. Moreover, the environmental conditions at sea make the in-situ measurements more difficult and more expensive
than over land. As an example, the oceanic meso-scale eddies, which dominate the oceanic signal in most basins, have a typical size between 10 and 300 km,
while the atmospheric synoptic perturbations have a typical size of 1000 km. The temporal spectrum of significant oceanic signals is also very wide,
between a few hours (surface waves, internal waves, tides...) and a few months or years (eddies, equatorial waves, subtropical gyres and associated currents).
All these reasons make the earth observation satellites an unique opportunity to observe the oceans with the necessary coverage, sampling and availability
in operational conditions, which an in-situ measurement network would never fulfil alone. Nevertheless, the ocean is opaque for electromagnetic radiation,
which implies that only surface signals can be observed from space. As a consequence, the knowledge of the three-dimensional structure of the oceans requires
the combined use of satellite observations, in-situ observations and ocean numerical models through assimilation techniques.
Momentum exchange between the atmosphere and the ocean determines wave spectra, storm surges, ocean circulation.
The measurement of near-surface wind by scatterometer is of utmost importance.
In addition to the Sea Surface Temperature (SST), two important components of the heat budget at the ocean surface, which drives its evolution,
can be inferred from satellite visible and infrared radiometers : the radiative short wave (SSI) and long wave (DLI) fluxes. No direct routine measurements
of the radiative fluxes are available from ships or buoys, as the maintenance of pyranometers or pyrgeometers at sea is very difficult, and
requires in addition a frequent cleaning of the instruments. Moreover, the estimates of these fluxes, provided by the NWP outputs suffer
from a lot of systematic errors due to the weaknesses of models radiation and cloud parameterisations, to the lack of upper-air observations
over the oceans, and model spin-up problems.
Accurate information on sea ice is also crucial for a range of applications from operational NWP and numerical ocean models
to climate research. Combining data from different satellites and sensors in a multi-sensor approach ensures an optimal use of available real-time satellite data.
2 - PROJECT PHASES and CONSORTIUM
- 1997 - 2002 : Development phase
- July 2002 - February 2007 : Initial Operational Phase (IOP)
- March 2007 - February 2012 : Continuous Development and Operations Phase (CDOP)
- March 2012 - February 2017 : CDOP-2
The CDOP-2 consortium is constituted of Meteo-France, as host institute, and of the following co-operating institutes :
MET Norway (Norway),
DMI ( Denmark),
Ifremer ( France),
KNMI ( Netherlands).
3 - A CONTINUOUS ADAPTATION TO THE USERS REQUIREMENTS
Initially, i.e. for the development phase (1997-2002) the OSI SAF was conceived as an answer to implicit requirements
from the meteorological and oceanographic communities of EUMETSAT Member States and Co-operating States for a comprehensive
information derived from meteorological satellites at the ocean-atmosphere interface.
Since the start of the OSI SAF Initial Operational Phase, new requirements sources appeared, in particular in the context of :
- at International level : the Global Ocean Data Assimilation Experiment (GODAE), and its High Resolution Sea Surface Temperature Pilot Project (GHRSST-PP),
and the Global Climate Observing System (GCOS),
- at European level : the European Programme for the establishment of a European capacity for Earth Observation (Copernicus)
and its Marine Service provided on a pre-operational mode by MyOcean Follow-On consortium
The current phase of the EUMETSAT OSI SAF, the CDOP-2 (Continuous Development and Operations Phase number 2), covering the period from 2012 to 2017,
has taken into account new requirements expressed at international level in particular by WMO, GCOS, GHRSST, etc, and at European level by MyOcean (precursor of the Copernicus Marine Service),
with a strong need for increasing the temporal and geographical resolution of the products and for extending the coverage range from coastal to global.
CDOP-2 is also consolidating assets by enhancing the algorithms and products, by increasing the effort on reprocessing, by taking into account new satellites.
The OSI SAF is preparing its next phase, the CDOP-3, that will cover from 2017 to 2022. CDOP-3 will take into account new satellites (in particular MTG, GOES-S, EPS-SG).
Last update : October 2014