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1.4 Terrestrial observations 
Depending on the terrestrial variable different government and research institutions at the 
Federal and Laender level are responsible. Observation of some terrestrial variables is im 
possible within Germany. Thus observing sites for such variables are also funded in foreign 
countries. 
1.4.1 The Global Runoff Data Centre (GRDC) 
The Global Runoff Data Centre (GRDC) was established in 1988 at the Federal Institute of 
Flydrology (BfG) under the auspices of the WMO. It is a contribution of Germany to the World 
Climate Programme Water (WCP-Water) of the WMO. WMO mandates and directly supports 
GRDC through its Resolution 21 (Cg XII, 1995: Request to the member states to provide 
GRDC with river discharge data) and Resolution 25 (Cg XIII, 1999: Free and unrestricted 
exchange of hydrological data). The main objective of the GRDC is the world-wide acquisi 
tion, storage and dissemination of historical and near real-time river discharge data in sup 
port of the predominantly water and climate related programmes and projects of the United 
Nations (UN), their specialised agencies and the scientific research community. 
The provision of hydrological data by National Hydrological Services to the GRDC is for the 
majority of the countries only happening sporadically, despite WMO resolutions. The GRDC 
is seeking to improve and operationalise the provision of data for the benefit of the research 
community. 
1.5 Space-based observations 
For the identification and assessment of changes in the climate system, satellites 
offer unique advantages: they provide continuous, seamless and timely data for regions 
where there are no or only sparse other observation data available; the data relating to vari 
ous regions come from one and the same observing system; some information, such as the 
radiation budget at the top of the atmosphere, can only be determined by means of a satellite 
system. 
1.5.1 Participation to relevant European Satellite Programmes 
Germany is the largest contributor to all European satellite programmes of ESA, EUMETSAT 
and the EU relevant for climate monitoring. 
Of particular relevance for the investigation of the processes within the climate system are 
the experimental (the Earth Explorers) and pre-operational (such as ENVISAT with its multi 
tude of land, atmosphere and ocean sensors) ESA Earth observation programmes. 
Notably in 2009 three relevant Earth Explorer Missions are scheduled to be launched. The 
Gravimetry Mission GOCE was launched in March 2009 and is expected to provide decisive 
measurement of the geoid. Combined with altimetry observations this will significantly help to 
constrain ocean surface currents. In November and December, SMOS and CryoSat-2, are 
planned to be launched. With observations of soil moisture, ocean salinity (SMOS) and ice 
dynamics in Polar Regions (CryoSat-2), these missions will provide important information on 
the climate system. 
ESA has also launched a major new programme dedicated explicitly to the generation of a 
number of Thematic Climate Records of ECVs, according to the GCOS IP. Germany is con