GCOS GOOS WCRP/OOPC IX/3
Recommendations to meet the operational requirements for satellite measurements
3 altimeters beyond 2007. A multi satellite system for continuous high resolution altimetry is likely to
involve a constellation of satellites and / or include the use of swath altimetry techniques and must
urgently include a high inclination altimeter mission (post ENVISAT) after 2007. This mesoscale
altimeter mission is needed to complement Jason 2 (planned launch in 2008) and to constrain in a
satisfactory way the open ocean currents and their mesoscale variability. In addition, an independent
mapping of the high resolution geoid form an essential component of long term altimetry strategy. The
planned launch of the GOCE mission in 2006 secures this.
At least 3 infrared radiometers beyond 2007. A long term commitment, beyond 2007, is needed to
provide high quality high resolution SST measurements from combined use of passive microwave and
infrared radiometers, following the multi sensor strategy proposed for the GHRSST PP and
complemented by the view of the Eumetsat Satellite Application Facilities. Regarding GHRSST PP
this implies the need to maintain at least one sensor in orbit having measurement stability and accuracy
equivalent to that of the ATSR/AATSR series of sensors.
3 ocean colour spectrometers beyond 2007. There is an increasing demand for high resolution
measurements of chlorophyll derived from ocean colour data, based on at least 2 3 different concurrent
missions in order to minimise the limiting effects of cloud cover effects, and served in near real time for
validation of or assimilation into marine biogeochemical models. In case 2 waters it is also important to
derive reliable observations of suspended matter from satellite colour data.
2 3 SARs to about 2007. Spaceborne SAR data is a highly needed source of information for detection
of oil spills both from illicit vessel discharges and major accidents (e.g. Prestige case). The continuous
use of multiple platforms and wide swath sensors (minimum of 2 3) is necessary to maintain sufficient
temporal and spatial coverage.
At least 2 scatterometers to beyond 2010. Measurement of wind vectors over the sea with 25 km
resolution and global daily coverage must be made available in support of operational basin scale ocean
forecasting models. Passive radiometry and scatterometry can also be combined.
Recommendations to meet the operational requirements for In Situ Measurements
Argo, VOS and Ferry boxes: The deployment of Argo profiling floats should be sustained, while the
use of VOS and Ferry Boxes through European coastal and shelf seas should be significantly increased.
Rapid data transmission: New integrated data network systems must be established for rapid
transmission of very high rates of raw data to processing centres and derived products to operational
users locally as well as regionally. There are both technical and policy obstacles to be tackled.
Sea Level: A network of coastal and buoy stations measuring sea level must be maintained throughout
European waters and the adjacent ocean.
Observatories: The development and operation of integrated observatories at selected tie points
(minimum 10 sites) along the European coastal and regional seas, such as the one operating in the Irish
Sea, is the only way towards routine and sustained in situ monitoring for environment (physical,
biogeochemical) and security (oil spills, red tides, toxic algal blooms).
HF radars: The number of operating short and long range HF radar systems should increase to at least
10 (today 3 systems are operating) and be implemented at selected observatories.
Biogeochemical sensor development: There is a developing need to be able to measure pigments,
nutrients, dissolved gases and other biogeochemical properties in the sea at fine spatial and temporal
resolution. This requires new chemical sensors to be developed that permit high frequency and semi
autonomous sampling from buoys as well as from VOS and ferry boxes.
River discharges: There is an urgent requirement for a routine monitoring system of river discharges
(volume and nutrients) into coastal seas. The present lack of near real time dissemination of data on
river discharges is a major limitation for coastal environmental monitoring.
Requirements for improving the modelling capability
Skill Assessment: There is a need for systematic examinations of the performances of forecasting
models which quantify their dependence on the availability, timeliness and quality of measured ocean
data from satellites and in situ systems.
Downscaling: The regional high resolution forecasting systems improves with systematic and reliable
information on the open boundaries from global and basin scale systems.