Global Energy and Water Exchanges
GEWEX Organization, Science Questions & Imperatives
Version: 2.0.0 (November 22, 2013)

PETER J. VAN OEVELENAND SAM BENEDICT1Outline‣ Introduction‣ WCRP and GEWEX, history and overview‣ GEWEX Science
WCRP Grand Challenges
GEWEX Science Questions
GEWEX Organization
GEWEX Regional Activity Relevant to African Water Cycle
Symposium‣ Conclusion2

World Climate Research ProgrammeSponsored by the World Meteorological Organization, theInternational Council for Science and the Intergovernmental
Oceanographic Commission of UNESCO.

‣ The WCRP Mission: to facilitate analysis andprediction of Earth system variability and change foruse in an increasing range of practical applications of
direct relevance, benefit and value to society.

3World Climate Research ProgrammeSponsored by the World Meteorological Organization, the International Council for Science and the Intergovernmental
Oceanographic Commission of UNESCO.

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4GEWEX

A brief history‣ Born out of the realization that the Earth observational
systems at that time (the early 1980’s) needed to be improvedon if more progress was to be made on the meteorology andglobal climate research.
‣ Two feasibility workshops were held in 1987 and 1988 and in
the first part of 1990 a science plan was finalized‣ In December of 1990 the Global Energy and Water cycle
Experiment (GEWEX) was approved by WMO and ICSU as acore project of the World Climate Research Programme(WCRP)

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Phase III: 2013 ~ 2022
Science Objectives & Imperatives‣ Building upon the results and experience from Phase I and II
the GEWEX community for Phase III has developed through anopen and interactive process:•A new Name, Vision and Mission Statement•Driven now by the WCRP Grand Challenges and the development of•The GEWEX Science Questions that map into the Grand Challenges andwhich will be addressed in the next 5 to 10 years partly facilitatedthrough the GEWEX Imperatives.

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GEWEX Mission
To measure and predict global and regional energy andwater variations, trends, and extremes (such as heatwaves, floods and droughts), through improved
observations and modeling of land, atmosphere andtheir interactions; thereby providing the scientificunderpinnings of climate services.

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Grand Challenges

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Four GEWEX Science Questions
For the next 5 to 10 years

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Observations and Predictions ofPrecipitation

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Global Water Resource Systems3Changes in Extremes

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Water and Energy Cycles and Processes91. Observations and Predictions of Precipitation
How can we better understand and predict precipitation variability and changes?

‣ How well can precipitation be described by various observing
systems and what basic measurement deficiencies and model
assumptions determine the uncertainty estimates at various space
and time scales‣ How do changes in climate affect the characteristics (e.g.,distribution, amount, intensity, frequency, duration, type) ofprecipitation, with particular emphasis on extremes of droughts andfloods?
‣ How much confidence do we have in global and regional climate
predictions of precipitation?

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2. Global Water Resource Systems
How do changes in land surface and hydrology influence past and future changes in water
availability and security?

‣ How do changes in land surface and hydrology influence past andfuture changes in water availability and security‣ How do changes in climate affect terrestrial ecosystems,
hydrological processes, water resources and water quality,
especially water temperature?
‣ How can new observations lead to improvements in water
management?

11GEWEX Organization
Scientific Steering GroupInternational GEWEX Project Office

GEWEX Data andAssessments PanelGEWEXHydroclimatology
Panel

Global Atmospheric
System Studies

Global Land–Atmosphere
System Studies

Assessments

Regional Hydroclimate
Projects

Parameterization
Evaluation

Benchmarking

Model Diagnosis

Model Data Fusion

Radiation CodeComparison

Land-Atmosphere
Coupling

Global Data Products

Cross-Cuts

In Situ Observations
Global Data Centers
Radiation CodeComparison

12GHPGEWEX Hydroclimatology Panel

Regional Hydroclimate
Projects

Cross-Cuts

Global Data Centers

BALTEX

Extremes

GRDC

HYMEX

High Elevations

GPCC

MAHASRI

Regional Seasonal Forecasting

Hydrolare

NEESPIHEPEX

SaskRB

13Completed
LBA LPBMDB AMMA

ActiveBALTEX, HYMEXMAHASRI NEESPI
SaskRB

Proposed
HYVIC, BALTIC-EARTH
NAWP, OzEWEX

1516	  (Customized	  from	  GFCS)	  17	  Hydroclimate Project for Lake Victoria Basin (HYVIC)
Fredrick Semazzi – HyVic International Planning Committee (Chair)
Rosalind Cornforth, University of Reading, Helen Houghton-Carr, CEH/NERC, Caroline Bain,UKMO, Ricard Anyah, U. of Connecticut, Rita Roberts, NCAR/UCAR, Lian Xie, North Carolina
State University, Laban Ogallo, Climate Prediction and Applications Centre (ICPAC), Pascal
Waniha, Tanzania Meteorology Agency (TMA)Andrew Githeko, Kenya Medical ResearchInstitute, Felix Mutua (Jomo Kenyatta University of Agriculture and Technology) – HyVicInternational Planning Committee (Members)
18	  Conclusion

The successful implementation of the WCRP Grand Challenges andassociated science questions described here depend significantly upon
the GEWEX Imperatives: observations and data sets, their analyses,
process studies, model development and exploitation, applications,technology transfer to operational results, and research capacity
development and training of the next generation of scientists.
They involve all of the GEWEX Panels and will benefit greatly fromstrong interactions with other WCRP projects such as CLIVAR, SPARC,and CliC and other sister global environmental change researchprograms.

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Contact Us
Peter van Oevelen
Director International GEWEX Project Office
gewex@gewex.org+1 (240) 485-1855

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