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NEWS NEWS Vol. 16, No. 1 February 2006 Global Energy and Water Cycle Experiment World Climate Research Programme (A Programme of WMO, ICSU and IOC) Newsletter Contents Commentary: GEWEX, AMMA, and Capacity 2 Building in Africa GEWEX Welcomes New SSG Members and 3 Chinese GEWEX Coordinator Recent News of Relevance to GEWEX 3 Highlights from the 18th Meeting of the 4 GEWEX Scientific Steering Group AMMA and Its First International Conference 5 Address the West African Monsoon African Contribution to AMMA 6 New GLASS Chair/AMS Awards/Tyler Prize 7 Impacts of and Adaptation to Changes in 8 the West African Monsoon European Contribution to AMMA 9 AMMA Land-Surface Modelling and 10 Intercomparison Projects US Contributions to the 2006 AMMA 11 Field Campaign TIGER Initiative 13 Global Surface Albedo Derived from 15 Geostationary Satellites GEWEX Relevant Publications of Interest 16 Workshop/Meeting Summaries: GLASS/GABLS Workshop on Local 17 Land-Atmosphere Coupling 3rd Session of the WGDMA 18 GEWEX/WCRP Meetings Calendar 19 AMMA WEST AFRICAN MONSOON STUDIES ARE ADDRESSING WATER CYCLE ISSUES African Monsoon Multidisciplinary Analysis (AMMA) obser- vations are based on nested networks from the regional scale (above) to the meso and watershed scales (e.g., right, inten- sively instrumented catchment). See articles on pages 5–11. Land-Surface Modelling and Intercomparison Studies (Page 10) Impact Studies (Page 8) African Contribution (Page 6) European Contribution (Page 9) US Contribution (Page 11) MERIS mosaic of Africa (courtesy of European Space Agency)

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Page 1: AMMA WEST AFRICAN MONSOON STUDIES ARE ADDRESSING … · AMMA WEST AFRICAN MONSOON STUDIES ARE ADDRESSING WATER CYCLE ISSUES African Monsoon Multidisciplinary Analysis (AMMA) obser-vations

NEWS NEWSVol. 16, No. 1 February 2006Global Energy and Water Cycle Experiment

World Climate Research Programme(A Programme of WMO, ICSU and IOC)

Newsletter ContentsCommentary: GEWEX, AMMA, and Capacity 2

Building in Africa

GEWEX Welcomes New SSG Members and 3Chinese GEWEX Coordinator

Recent News of Relevance to GEWEX 3

Highlights from the 18th Meeting of the 4GEWEX Scientific Steering Group

AMMA and Its First International Conference 5Address the West African Monsoon

African Contribution to AMMA 6

New GLASS Chair/AMS Awards/Tyler Prize 7Impacts of and Adaptation to Changes in 8

the West African Monsoon

European Contribution to AMMA 9AMMA Land-Surface Modelling and 10

Intercomparison ProjectsUS Contributions to the 2006 AMMA 11

Field CampaignTIGER Initiative 13Global Surface Albedo Derived from 15

Geostationary SatellitesGEWEX Relevant Publications of Interest 16Workshop/Meeting Summaries:

– GLASS/GABLS Workshop on Local 17 Land-Atmosphere Coupling

– 3rd Session of the WGDMA 18

GEWEX/WCRP Meetings Calendar 19

AMMA WEST AFRICAN MONSOON STUDIES ARE ADDRESSINGWATER CYCLE ISSUES

African Monsoon Multidisciplinary Analysis (AMMA) obser-vations are based on nested networks from the regional scale(above) to the meso and watershed scales (e.g., right, inten-sively instrumented catchment). See articles on pages 5–11.

Land-Surface Modellingand

Intercomparison Studies(Page 10)

Impact Studies(Page 8)African Contribution

(Page 6)

European Contribution (Page 9)

US Contribution (Page 11)

MERIS mosaic of Africa(courtesy of European

Space Agency)

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February 20062

COMMENTARY

GEWEX, AMMA AND CAPACITYBUILDING IN AFRICA

Richard Lawford, DirectorInternational GEWEX Project Office

This Newsletter issue deals with Africa andhighlights the African Monsoon MultidisciplinaryAnalysis (AMMA) Project that has recently beenlaunched by African, European and American sci-entists. Not only does AMMA address critical scienceissues but it will also help in developing the exper-tise and infrastructure that is needed to build Africa’sprediction capabilities and environmental develop-ment. These capabilities are needed on an urgentbasis because the West African Monsoon has amajor impact on the lives, health and prosperity ofmillions of people living in west and central Africa.As a project, AMMA not only bridges continentsin terms of the scientists involved, but also theinterests of GEWEX and the Climate Variabilityand Predictability (CLIVAR) Project, as well asother global environmental projects.

Sanitation and access to clean water are issuesfor many African countries. As desertification spreadsand droughts become more variable, more coun-tries, particularly in North Central Africa, willexperience conditions of severe water stress. Somecountries are using groundwater as an interim so-lution but this resource can only be “mined”(extracted at rates greater than it is being replen-ished by precipitation) for so long before it becomesdepleted.

AMMA presents an unusually broad range ofinterdisciplinary research activities and promises tomarshal both new scientific findings and many ofthe data sets needed to address water issues inWest Africa. AMMA has plans to bring togetherin situ and satellite observations, assimilation andmodelling capabilities, and application studies toprovide African nations with the knowledge and thetools that they need to address water problemsmore effectively.

US prediction services can derive major ben-efits from AMMA research in West Africa becausethis area and the nearby ocean serve as a spawningground for many of the hurricanes that affect thesouthern United States. This is a rich area forcollaborative research with THe Observing SystemResearch and Predictability Experiment (THORPEX).

Some countries in Africa have experienced dif-ficulty in developing their natural resources because

they lack the roads and infrastructure and also donot have the educational programs in place toprovide adequate training in selected disciplines.The lack of expertise and infrastructure makes en-vironmental monitoring very difficult and expensive.The African Development Bank and other organiza-tions are addressing the lack of roads andinfrastructure and also the issues related to educa-tion and training. AMMA supports these broaderdevelopment goals by building the levels of exper-tise in Africa in meteorology, hydrology andinterdisciplinary studies.

Some African countries have developed inde-pendent meteorological and hydrological services.In other cases, nations draw on centralized ser-vices by participating in organizations such as theAfrican Centre of Meteorological Application forDevelopment (ACMAD). The potential for the de-velopment of targeted applications by involvingthese organizations in climate research projects andactivities is very large. Opportunities also existwithin programs with which GEWEX is affiliated.For example, the Group on Earth Observations(GEO) work plan, which is supported by GEWEX,calls for a capacity building workshop to be heldin Africa. The European Space Agency and UnitedNations Educational Scientific and Cultural Organi-zation (UNESCO) have launched a developmentprogram, the Terrestrial Initiative in Global Envi-ronment Research (TIGER), where data fromEuropean and Canadian satellites are being used toimprove the management of regional and local waterresources in Africa. GEWEX plans to contribute tothese efforts and looks forward to advancing ourunderstanding of how environmental conditions onthis continent affect the global climate system andin turn how changes and variability in Africa'sclimate affect the vulnerability of societies andeconomies in this large continent.

As part of their outreach activities, GEWEXand AMMA plan to contribute to capacity building.In this context, capacity building is seen as aprocess for enhancing the ability of regional, na-tional and local stakeholders to evaluate and addresscrucial questions related to the use of environmen-tal information for better decisions related to theimplementation of the best options for resourcedevelopment and management. Over the next fewyears AMMA and GEWEX have the unique oppor-tunity to join forces with GEO, the IntegratedGlobal Observing Strategy–Partners Integrated GlobalWater Cycle Observations Theme and TIGER todevelop a coordinated approach for capacity build-ing in many West African countries.

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3February 2006

RECENT NEWS OF RELEVANCETO GEWEX

GEO MEETING RESULTS INMODIFICATIONS TO THE2006 GEOSS WORK PLAN

On 13–14 December 2005, the Group on EarthObservations (GEO) met in Geneva to discuss progressin developing the 2006 Work Plan and other centralGEO documents. Based on this meeting, the GEOmembers were asked to identify leaders for individualtasks and country representatives were asked to iden-tify areas in which they would like to make contributions.The GEO Users Interface Committee met the follow-ing day and endorsed a number of Community ofPractice proposals including those for water and healthand coastal zones.

FALL AGU SESSIONS DEALWITH GEWEX ISSUES

Several sessions held at the Fall American Geo-physical Union (AGU) in December 2005 dealt withareas that GEWEX is currently developing. In par-ticular, IGPO co-sponsored a session on orographicprecipitation that reviewed the range of issues relatedto the climatological, meteorological, modelling andobservational challenges associated with the formationof precipitation in complex terrain.

MAHASRI AND ASIAN WATER CYCLEPLANNING MEETINGS HELD IN TOKYO

The University of Tokyo was the site of twomajor workshops in November 2005. The first work-shop brought together the international science communitythat is preparing the science and implementation planfor the Monsoon Asian Hydro-Atmospheric ScienceResearch and prediction Initiative (MAHASRI). Over50 people commented on MAHASRI plans and dis-cussed how to move forward with its implementation.The subsequent meeting dealt with the expansion ofinstrument networks across eastern Asia to benefitthe Coordinated Enhanced Observing Period (CEOP)and MAHASRI.

GEWEX WELCOMESNEW SSG MEMBERS

Jun Matsumoto

Associate Professor,Department of Earthand Planetary Sciences,University of Tokyo,Japan. E-mail: [email protected]

Areas of Interest: Monsoon climatology, cli-matic impacts on ecosystems and agriculture.

Rucong Yu

Deputy Administrator,China MeteorologicalAdministration; Professor,Institute of AtmosphericPhysics, Chinese Academyof Sciences, P.R. China.E-mail: [email protected]

Areas of Interest: Numerical modelling inatmospheric and oceanic sciences, and climate andweather dynamics.

CHINESEGEWEX COORDINATOR

GEWEX welcomesYuping Yan as the Chi-nese GEWEX Coordinator.Dr. Yan will work on thedevelopment and coordi-nation of GEWEX activitieswithin China. Her activi-ties will be evenly dividedbetween GEWEX and theNational Climate Center ofthe China MeteorologicalAdministration.

Dr. Yan received her Ph.D. in atmospheric phys-ics in 1999 and during the period of 2001–03 wasa Post Doc Fellow at the Climate Change Instituteand School of Marine Science at the University ofMaine. Her research interests are climate impactassessment and numerical simulation on interactionbetween land surface/ocean and atmosphere.

GOES REPOSITIONING TO IMPROVESOUTH AMERICAN COVERAGE

NOAA has agreed to move the GeostationaryOperational Environmental Satellite (GOES-10) fromits current position above the equator to a new loca-tion that will greatly improve coverage of the WesternHemisphere, especially South America. This move isplanned for October 2006, pending the successfullaunch of GOES-N and the continued operation ofGOES-12.

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February 20064

HIGHLIGHTS FROM THE18TH MEETING OF THE

GEWEX SCIENTIFIC STEERING GROUPDawn Erlich

International GEWEX Project Office

The GEWEX SSG-18 meeting was held in Dakar,Senegal, 9–13 January 2006. The meeting was hostedby the Université Cheikh Anta Diop with exemplarysupport from Dr. Amadou Gaye and his colleaguesfrom the Ecole Supérieure Polytechnique. The meet-ing was opened by the Directeur de la MétéorologieNationale du Sénégal and the President de l’Assembléede l’Université Cheik Anta Diop.

A special session was held on hydroclimatologyresearch in Africa and on the African MonsoonMultidisciplinary Analysis (AMMA) Project. Dr.Daniel Rosenfeld from the Hebrew University ofJerusalem gave a scientific presentation on his re-cent research related to the thermodynamic responsesto precipitation changes induced by surface andaerosol impacts on cloud processes.

In addition to the annual review of GEWEXactivities, this SSG provided an opportunity to reviewlinkages with other WCRP projects, including: theClimate Variability and Predictability (CLIVAR) Project,the Climate and Cryosphere (CliC) Project, and theWorking Group on Numerical Experimentation (WGNE);as well as with other international communities includ-ing: the International Geosphere-Biosphere Project(IGBP)/international Land Ecosystem-Atmospheric Pro-cesses Study (iLEAPS); the Global Earth ObservationSystem of Systems (GEOSS); the Integrated GlobalObserving Strategy-Partnership (IGOS-P); THe Ob-serving System Research and Predictability Experiment(THORPEX); the Global Water System Project(GWSP); the UNESCO International HydrologicalProgramme and the Water And Development Infor-mation for Arid Lands–A Global Network (G-WADI);

and the Hydrology and Water Resources (HWR)Programme of the World Meteorological Organization.

Some of the SSG meeting highlights include:• Two special journal issues are planned with

results from the 5th International ScientificConference on the Global Energy and WaterCycle and the Coordinated Enhanced Ob-serving Period (CEOP). A special issue onthe GEWEX Atmospheric Boundary LayerStudy benchmark case will appear in the Feb-ruary 2006 issue of the Journal of BoundaryLayer Meteorology.

• The GEWEX Asian Monsoon Experiment endedin March 2005. A science plan for a pro-posed follow-on project called the MonsoonAsian Hydro-Atmospheric Science Researchand prediction Initiative (MAHASRI) was pre-sented and received approval in principal,subject to approval by the GEWEX Hydrom-eteorology Panel (GHP) at its next meeting.

• A draft version of the CEOP Phase II Imple-mentation Plan was presented and receivedpreliminary approval. CEOP Phase II will havetwo stages that run from 1 January to 31December 2010. The diurnal cycle was adoptedas one of the scientific themes.

• A GEWEX Radiation Panel led LandFluxactivity is being developed to derive land-surface fluxes from satellite data. Whencombined with SeaFlux products, these fluxescould be used to address the entire globalwater and energy budget.

• The GEWEX European Coordinator has pre-pared a Category-1 proposal for the EuropeanSpace Agency to release data for CEOP.

• The role of the Water Resources Applica-tion Project has beenredefined as the Hy-drologic ApplicationsProject (HAP). Ex-amples of initiativeswith promising links toHAP include the Hy-drological EnsemblePrediction Experiment,the Project forUngauged Basins, andTHORPEX.

Participants at the 18th Meeting of the GEWEX Scientific Steering Group.

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5February 2006

AMMA AND ITS FIRST INTERNATIONALCONFERENCE ADDRESS THE

WEST AFRICAN MONSOON

Jean-Luc Redelsperger1, Chris Thorncroft2,Arona Diedhiou3, Thierry Lebel3,

Douglas Parker4, and Jan Polcher5

1CNRM/GAME CNRS and Météo-France,2SUNY at Albany, US, 3LTHE/IRD, Niger,

4University of Leeds, UK, 5LMD/CNRS, France

The West African monsoon (WAM) is a coupledland-ocean-atmosphere system characterized by sum-mer rainfall over the continent and winter drought.Over the land the effects of the monsoon are mostevident over an area stretching eastward from a linebetween Cameroon in the south and Niger in thenorth to the west coast of Africa. The annual cycleof rainfall in the West African region is characterizedby a poleward migration of peak rainfall up to Augustfollowed by a more rapid retreat. It also includes anapparent “jump” in the location of peak rainfall at theend of June from the coastal region around 5oN toabout 10oN. The precipitation is provided by the ubiq-uitous mesoscale convective systems and synopticAfrican easterly waves. Ultimately the nature of thesurface conditions over the land (e.g., soil moisture,vegetation) and over the ocean (sea surface tempera-tures) determine the nature and variability of the WAMon interannual and longer timescales. In addition, theSahara, just north of the rainy zone, provides theWAM an abundant supply of dust which may interactwith and impact the intensity of the WAM.

Over the past 50 years the change in West Africafrom wet to much drier conditions is among thestrongest interdecadal signals of the past century.

This drying trend coupled with marked interannualvariations has had devastating environmental and socio-economic consequences.

Fundamental gaps in our observation, understand-ing, and modelling of this complex system havelimited our prediction skills. To bridge these gaps,the African Monsoon Multidisciplinary Analysis (AMMA)Project, has adopted a multidisciplinary approach,involving substantial international collaboration thatlinks observation, data analysis and modelling on awide range of space and time scales.

The processes that couple the land, ocean andatmosphere take place in association with multipleinteracting space and timescales. To address themultiple scales that characterize the WAM, AMMA isstructured around four interacting spatial timescales(see figure on page 20). AMMA is a multi-yearproject with three nested observation periods, LOP(2002–2010), EOP (2005–2007), and SOP (2006),which stand for the long-term, enhanced, and specialobserving periods, respectively.

The AMMA Project has three overarching aims:(1) improve our understanding of the WAM and itsinfluence on the physical, chemical and biologicalenvironment, regionally and globally; (2) provide theunderpinning science that relates variability of theWAM to issues of health, water resources, foodsecurity and demography for West African nationsand defining and implementing relevant monitoringand prediction strategies; and (3) ensure that themultidisciplinary research carried out in AMMA iseffectively integrated with prediction and decision-making activity.

Scientists from more than 30 countries, represent-ing more than 130 institutes are involved in AMMA.AMMA receives funding from the European Union,

Participants at the First International AMMA Conference.

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February 20066

AFRICAN CONTRIBUTION TO AMMA

Amadou Thierno Gaye1 andArona Diedhiou2

1Ecole Supérieure PolytechniqueUniversité Cheikh Anta Diop, Dakar, Senegal

2LTHE/IRD, Niger

The entire West African region, especially theSahel, has experienced one of the strongest interdecadalsignals in the world, passing from wet conditions inthe 1950s and 60s to much drier conditions in the1970s, 80s and 90s. This has impacted all compo-nents of the water cycle and raised important issuesrelated to sustainability, land degradation, and foodand water security in the region. The development ofstrategies to reduce the socio-economic impacts ofclimate variability in West Africa is a priority. Re-search from the African Monsoon MultidisciplinaryAnalysis (AMMA), an international project designedto improve our understanding of the West AfricanMonsoon (WAM) and its variability at different timeand spatial scales, will improve prediction of theWAM and its impacts.

The AMMA program provides a unique opportu-nity for the international scientific community tocontribute to the training and capacity building inAfrican countries, regarding geosciences and theirimpacts (e.g., meteorology, hydrology, atmosphericchemistry, oceanography, agronomy) before, duringand after the field program. AMMA will also raise thestandard of climate and environmental research inAfrican institutions supported by doctoral and masterprograms, summer schools and workshops. At thesame time, there are areas (e.g., forecasting, humandimensions) in which African institutions have anequal contribution to make in developing environmen-tal and climate science.

AMMA-Africa involves scientists from many Af-rican countries and disciplines, including the NationalMeteorology and Hydrology Services (NMHS), anduniversities and regional centers, such as the RegionalCenter on Agriculture, Hydrology and Meteorology(AGRHYMET) and the African Center for Meteorol-ogy Applied to Development (ACMAD). The AMMA-Africa Steering Committee includes representativesfrom 15 West African countries (Benin, Burkina Faso,Cameroon, Cabo Verde, Chad, Côte d’Ivoire, Gambia,Ghana, Guinea Bissau, Guinea Conakry, Mali, Niger,Nigeria, Senegal, Togo) and by an AMMA NationalCommittee composed of members of the NMHS.AMMA-Africa provides a framework for Africanscientists to: (1) develop and consolidate links be-tween research institutions and NMHS with the aim

France Action Programme Inter-organisme and theUnited Kingdom, as well as the United States andpan-African projects.

The GEWEX Scientific Steering Group approvedAMMA as a Continental-Scale Experiment (CSE) inFebruary 2005, thereby ensuring strong links betweenthe scientific advances in AMMA and other CSEs, aswell as interactions with coordinated internationalmodelling activities, such as the GEWEX GlobalLand-Atmosphere System Study (GEWEX News,August 2004, February 2005). AMMA also has stronglinks to international projects, such as the ClimateVariability and Predictability (CLIVAR) Project, theInternational Geosphere-Biosphere Programme Inter-national Global Atmospheric Chemistry Project andinternational Land Ecosystem-Atmospheric ProcessesStudy, and the Global Climate Observing System andGlobal Ocean Observing System. In collaborationwith THe Observing System Research and Predict-ability Experiment (THORPEX), AMMA is addressinghigh impact weather prediction and predictability.

The First International AMMA Conferencewhich was held in Dakar, Senegal, 28 November–2December 2005, was very successful with 255 par-ticipants from 23 countries and more than 300 abstractssubmitted. The Conference brought together re-searchers from around the world working on theWAM and its impacts, to review ongoing researchactivities and to discuss future contributions anddirections within the AMMA research program. Italso provided the first real opportunity for establish-ing and coordinating collaborations at the internationallevel, and in particular with African scientists.

The Conference program included a mixture ofplenary sessions, poster sessions and parallel workingsessions. The plenary sessions included invited andcontributed oral presentations. The working sessionswere designed to provide an opportunity to discussfuture research directions in AMMA as well as tocoordinate and promote international collaboration. Aworkshop dedicated to climate impacts took placeimmediately after the conference and a training work-shop on monitoring and forecasting the Africanmonsoon impacts on agriculture and vegetation washeld the following week in Thiès.

The AMMA Project articles appearing inthis issue involve numerous members of theAMMA team who cannot all be acknowl-edged here. For contact information for allkey Project contributors, please seewww.amma-international.org.

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7February 2006

of improving products for end-users; (2) provideassistance in responding to different calls for propos-als; (3) exchange information, data and tools; (4)federate the initiatives and the individual suggestionsfor more efficiency; and (5) organize workshops andseminars.

The AMMA-Africa Science Plan or Pland’Implementation Africain (PIAF), is based onindividual and small team research proposals madeby scientists in the region from universities, NMHS,and research centers. The goals of the PIAF are:(1) improve weather and climate prediction overWest Africa; (2) evaluate the impacts of climatechange on sectors (e.g., agriculture, health, waterresources, pastoralism, coastal areas); (3) integratemultidisciplinary research for policy making; (4)initiate dialogue between the AMMA national com-mittees and stakeholders; and (5) initiate nationaland regional capacity building through training andresearch.

The primary components of the PIAF are inte-grative geophysical and impact studies related tothe impacts of WAM on water resources, agricul-ture, health and environment. Its implementationwill contribute to improved knowledge of meteoro-logical and hydrological sciences and to theoperational activities of NMHS. This accounts forthe strong involvement of regional centres (e.g.,ACMAD, AGRHYMET) in the implementation ofthe AMMA Project.

The AMMA observational strategy combines mea-surements from existing and updated operationalnetworks with additional observations concentratedwithin sub-regional windows where enhanced obser-vations will be carried out during special observingperiods. The value of additional, long-term observa-tions in this region of poor data coverage will beassessed with models and data assimilation tools.Strengthened capacities related to systematic climateobservations, data processing and archiving are seenas the major expected spin-offs by the NMHS di-rectly involved in the implementation of this internationalprogram.

The World Meteorological Organization's endorse-ment of AMMA-Africa is expected to facilitate theintegration of the contributions from the African NMHSwith respect to operational aspects of the programand to help them to attract funds from their govern-ment and sponsors. The new program should lead tosignificant and sustainable results for the region, in-cluding an accurate observation network, tools andapplications for decision making and early warning,and the development of a strong scientific communitydedicated to studies of WAM and its impacts.

GEWEX SCIENTISTS HONOREDAT THE ANNUAL AMS MEETING

At the 86th Annual Meeting of the AmericanMeteorological Society, Paul Dirmeyer, NSF, re-ceived the Clarence Leroy Mesinger Award "forimproved understanding of the role of soil moisturein land-atmospheric coupling, climate variability andclimate predictability, and for leadership in GEWEXland modelling activities."

Soroosh Sorooshian, University of California,Irvine, was honored as the Robert E. Horton Me-morial Lecturer. His talk was on “Significantcontributions for estimating precipitation from space-based imagery and the application to semi-arid regionhydrology and water resources management.”

Other GEWEX affiliates to receive AMS hon-ors include Robert Houze, University of Washington(Rossy Award) and Julia Paegle, University ofUtah (ABBE Award). Maria A.F. Silva Dias,CPTEC/University of Sao Paulo, KonstantineGeorgakakos, Hydrologic Research Center, andDa-Lin Zhang, University of Maryland, were hon-ored as new AMS Fellows.

NEW GLASS CHAIR

Andrew Pitman, Professor at the Departmentof Physical Geography, Division of Environmentaland Life Sciences, Macquarie University, Sydney,Australia, is the new chair of the Global Land-Atmosphere System Study (GLASS). He replacesPaul Dirmeyer, who is now managing the Climateand Large-Scale Dynamics Program at the Na-tional Science Foundation (NSF). Bart van den Hurkof the Royal Netherlands Meteorological Institutewill serve as the GLASS vice-chair.

Former GEWEX Scientific Steering Group mem-ber, Igor Shiklomanov of the State Hydrological Institutein Russia, has been named co-recipient of the 2006Tyler Prize for Environmental Achievement. Estab-lished by Los Angeles philanthropists John and AliceTyler, the Tyler Prize is considered the premiere in-ternational award honoring achievements in environmentalscience, energy, and medical discoveries of world-wide importance that impact upon human existence.

TYLER PRIZE AWARDED TO FORMERGEWEX SSG MEMBER

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February 20068

There are many reasons to assume that futurechanges in the West African Monsoon (WAM) willstrongly impact living conditions, food security andnational economies. In the last rain deficit period,changes in ecosystems functions, vegetation speciescomposition, river discharge (and thus water re-sources for irrigation) and groundwater availabilitywere observed.

In the African Monsoon Multidisciplinary Analy-sis (AMMA)-Impact Project, partnerships betweeninstitutions from Europe in AMMA-EU and theAfrican research community will be formed aroundresearch projects related to climate change andvariability of the WAM. These include: (1) changesin water resource availability, its impact on irri-gated and rain-fed agriculture, and adaptation measuresand strategies; (2) climate change impacts on landuse/land cover, and natural vegetation productivityand pastoral production systems; (3) developmentof improved seasonal forecasts guiding agriculturaloperations; (4) development and use of policyrelevant climate change scenarios as input to im-pact, mitigation and adaptation studies.

The interannual rainfall variation observed in WestAfrica during the last 50 years has been characterizedby a decreasing annual rainfall of 15–35% betweenthe humid years (before 1970) and drought period(post-1970) which has impacted the discharge ofSahelian rivers. The mean annual discharge variesfrom 40–60% between the humid and drought peri-ods. Impacts of and the adaptation to climate changein the agricultural sector in the Sahel-Sudan mayinvolve a range of different responses:

• Changes in agricultural land use at themacroscale. In periods of deficit rainfall, crop-lands may be converted into rangelands.

• Changes in land use and agricultural prac-tices at the microscale. Individual farmersare expected to adapt to variations in rain-fall by selecting suitable field locations, and

IMPACTS OF AND ADAPTATION TOCHANGES IN THE

WEST AFRICAN MONSOON

Inge Sandholt1, Abou Amani2, andKjeld Rasmussen1

1Institute of Geography, University ofCopenhagen, Denmark

2Responsable UIR Maîtrise de l’Eau,Centre Regional AGRHYMET, Africa

taking local soil and terrain conditions intoaccount.

• Changes in crop choice. Choosing betweensubsistence oriented crops (e.g., millet) andmarket-oriented crops (e.g., cotton andgroundnuts), as well as between cultivars.

• Irrigated agriculture. May expand in thecase of reduced rainfall, yet may be con-strained by the availability of surface/groundwater resources.

It should be noted that all of these adaptivestrategies are also relevant for other external changes,such as changes in prices of products and inputs(locally or globally), and changes in employmentoptions in other sectors and outside the region.Farmer adaptation to climate change and variabilityin the Sahel-Sudan must be studied in the contextof other important external influences. Also, landuse policies must be considered along with wateruse and water policies, particularly in relation toirrigated agriculture. National natural resource poli-cies and national capacities for planning andmonitoring environmental change may have greatimportance. Climate change will also impact theavailability of water resources, and since hydro-power is of considerable importance in severalcountries, there is also a direct link between changesin rainfall and power production. Thus, adaptationto climate change and variability involves not onlyindividual households and rural communities, butalso national governments and administrations. Anefficient coupling between local, regional, nationaland international coping systems is crucial for mini-mizing climate-related economic losses.

As indicated above, impacts of and adaptation toclimate change and variability must be seen in thecontext of broader development issues. Therefore,climate change adaptation and the pursuit of the UNMillenium Development Goals, including poverty alle-viation, strongly overlap with the agriculture sectorand rural livelihoods and in environmental themes,such as desertification and biodiversity. This sug-gests that climate change and variability adaptationstrategies should form part of general rural and agri-cultural development strategies.

The strong international partnerships in AMMA-Impact will not only strengthen our understandingof the impacts of climate change, but also contrib-ute to capacity development. Through the stronginvolvement of African partners, it will contributesignificantly to policy development and in the longerrun to sustainable development in West Africa.

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9February 2006

standing of which of the slow components in thesystem have the strongest predictive skill andwhich process needs to be better understood.Key to any significant progress will be an inte-grative approach that views the monsoon as anobject built out of internal interactions but withstrong external influences. An improved concep-tual view of the monsoon will lead to betterstatistical forecasts as well as more accuratedynamic seasonal forecasts and allow us to es-timate error bars for the climate change studies.

Food security management. West Africa ischaracterized by a low income household economymainly based on rain-fed agriculture. The signifi-cant increase in demographic pressure, theprogressive impoverishment of natural resourcesand the vulnerability of rainfall-dependent agri-cultural systems make West Africa the most foodinsecure area in the world. Understanding theeffects of the WAM on regional and local foodsecurity involves studying the direct effect of themonsoon on agricultural productivity and adap-tive mechanisms. AMMA-EU will estimate therange of direct and indirect effects of changes inthe monsoon on the vulnerability of food secu-rity over the region and improve the predictionof seasonal production to serve as input forearly warning systems. The direct effects willinclude changes in yields of rain-fed crops andchanges in water resources available for irrigatedcultivation. Indirect effects include changes inagricultural and livelihood strategies as well asland use.

Environmental monitoring. The African con-tinent has poor coverage by operational atmosphericobservations. For example, the rain gauge networkis in steady decline and does not provide a satis-factory basis for water management. This considerablyhinders the specification of initial conditions forforecasting systems and contributes little to long-term monitoring for climate change detection andattribution studies. AMMA-EU is implementing amultiscale and integrated monitoring network toprovide key parameters for multidisciplinary scien-tific investigations. In particular, it will help todetermine future operational monitoring strategies.The African radiosonde network is being upgradedand personnel will be provided with the appropri-ate training to maintain the network over the longterm. The project will demonstrate the benefit ofthese enhancements in the upper air soundings forweather and climatic forecasting to motivate theirfunding at an international level.

A consortium of 41 European and African in-stitutions were awarded a grant from the EuropeanUnion (EU) within the 6th Framework Program tocontribute to the African Monsoon MultidisciplinaryAnalysis (AMMA) Project. While the aims of thisintegrated European project are the same as AMMAits main objective is to coordinate the contributionof the European research community and the na-tional agencies in Europe which also fund AMMA.The following briefly describes the main areas ofresearch in AMMA-EU.

Improve short- to medium-range weather fore-casting. Due to the difficulty in accurately simulatingkey elements of the West African Monsoon (WAM),accuracy in short- to medium-range precipitationforecasts has been poor. Accurate forecasts areessential for early warning systems for food secu-rity, risk management and civil protection in Africa.With its intensive field campaign, AMMA-EU willprovide the data needed to examine hypotheses ontropical convection, its interaction with the large-scale dynamics, and its role in the regional watercycle. Within this project, process studies on con-vection will be integrated with an improved knowledgeof land-surface processes and interactions withaerosols and chemistry in order to be translatedinto improved parameterizations for the large-scalemodels used in forecasting.

Seasonal to climate forecasting. The statisti-cal forecasts of the seasonal rainfall over Africahave not been surpassed by their deterministiccounterparts as is the case in many regions of theworld and as would be expected from theoreticalconsiderations. Present deterministic forecasts areonly forced by the sea-surface temperature variabil-ity. Models disagree on the sign and amplitude ofrainfall changes for a climate with increased green-house gases. This state of affairs can be ascribedto the complex and poorly understood interactionsbetween the monsoonal oceanic, land-surface andatmospheric processes. Progress in this area iscritical for the food security at the shorter rangeand the development of agronomic adaptation strat-egies at longer time scales. The long-term monitoringof the water cycle by AMMA-EU will improve ourunderstanding of the characteristics of the interannualrainfall variability. This will provide an under-

EUROPEAN CONTRIBUTION TO AMMA

Jan PolcherLaboratoire de Météorologie Dynamique

du CNRS, France

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AMMA LAND-SURFACE MODELLINGAND INTERCOMPARISON PROJECTS

Patricia de Rosnay1, Aaron Boone2,Anton Beljaars3, and Jan Polcher4

1Centre d’Etudes Spatiales de la BIOsphère,France, 2Centre National de Recherches

Météorologiques, France, 3European Centrefor Medium-Range Weather Forecasts, UK,

4Laboratoire de MétéorologieDynamique, France

Land-atmosphere feedbacks in the West AfricanMonsoon (WAM) region have been shown to be ofcritical importance for atmospheric prediction in Af-rica and over the Northern Hemisphere (Koster et al.,2004). The distinguishing feature of land-atmosphereinteractions over West Africa is the large range ofthe spatial and temporal scales involved in the surfaceprocesses and their interactions with atmospheric pro-cesses. At the small scale, these interactions have animpact on convective cells within mesoscale stormsystems, while at the regional scale they influence theposition of the Intertropical Convergence Zone andthe African East Jet through a significant meridionalsurface flux gradient (Taylor et al., 1997). The diver-sity of processes involved in the WAM, and theirinteractions at different scales controls the processesthemselves, the water budget and the surface-atmo-sphere feedbacks, all of which are key scientificinvestigations of the African Monsoon MultidisciplinaryAnalysis (AMMA) Project.

The land surface modelling strategy of AMMArelies on the following structure: (1) The coordinateddevelopment and use of various Land Surface Models(LSMs), each focusing on different processes andworking at different temporal and spatial scales, overdifferent domains and sites in West Africa. Theseinclude hydrological models, soil-vegetation-atmospheretransfer schemes, crop models and the integrated "secondgeneration" land surface-models. (2) The creation ofa multiscale low-level atmospheric forcing databaseover land. These data are essential in order to havea coherent multi-disciplinary modeling approach atvarious scales for use by the large and diverse groupof land surface models considered in AMMA. (3)The development of an African Land Data Assimila-tion System. The European Centre for Medium-RangeWeather Forecasts are running the recently developedsoil moisture data assimilation system for the Africanarea using AMMA data and surface flux and soilmoisture data for verification. The off-line simulatedland surface state is being used to evaluate and pos-

sibly improve the current assimilation system (forestimating soil moisture) used at Météo-France.

The development and improvement of modelparameterizations, coupling, and calibration, as well asassimilation methods, are the basis for the suitabilityand consistency of the modelling studies conducted inAMMA. These activities are largely supported by thecomprehensive field campaign. The instruments willbe deployed during the course of AMMA for differ-ent periods: LOP (2002–2010), EOP (2005–2007),SOP (2006), which stand for the long-term, enhanced,and special observing periods, respectively. The afore-mentioned activities will also be supported by theAMMA-Satellite Working Group, thereby allowing de-velopers to access multi-sensor remotely sensed datasets. For more information about AMMA land-sur-face modelling, see: http://www.amma-eu.org/sections/work_packages/tools-methods/wp4_1.

The goal of attaining a coherent multi-disciplinarymodeling approach at various scales with a largegroup of land surface models is based on the needto build a multiscale forcing database. The coordina-tion of the land surface modelling activities in AMMAis supported by the AMMA LSM IntercomparisonProject (ALMIP). ALMIP involves AMMA-EU andAMMA-API partners. It is conducted along the samelines as previous LSM intercomparison studies, suchas the Global Soil Wetness Project (GSWP, Dirmeyeret al. 1999), the Project for the Intercomparison ofLand-Surface Parameterization Schemes (PILPS,Henderson-Sellers et al., 1995), the Rhône AGGregationLand Surface Scheme Intercomparison Project (Rhone-AGG, Boone et al., 2004), but focuses on Africa andspecific land-surface processes involving various spa-tial and temporal scales. The first phase of ALMIPis being conducted this year with integrated LSMsand SVAT models.

ALMIP has the following objectives: (1) intercompareresults from an ensemble of state-of-the-art models;(2) determine which processes are missing or notadequately modeled by the current generation of LSMsover this region; (3) examine how the various LSMsrespond to changing the spatial scale (three scaleswill be analyzed: the local, meso and regional scales);(4) develop a multi-model climatology of “realistic”high resolution (multiscale) soil moisture, surface fluxes,and water and energy budget diagnostics at the sur-face that can then be used by other projects withinAMMA; and (5) evaluate how relatively simple LSMssimulate the vegetation response (in terms of leaf areaindex or biomass) to the atmospheric forcing onseasonal and interannual timescales.

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A series of four 2-year experiments using datafrom 2003–2004 are being performed and consistof: (1) running the LSM at a regional scale (–20o

to 30o E, –5o to 20oN, on a 0.5o grid) usingnumerical weather prediction forcing data; (2) againusing hybridized forcing data; (3) doing a subre-gional or mesoscale (a north-south sub-zone usinga 0.05 to 0.10 degree resolution) simulation; and(4) running a LSM at the local scale. A secondoptional series of experiments repeats the abovewhile using LSMs to simulate the vegetation.

The input data has been distributed to the modelparticipants and the preliminary results are due thissummer. A several month period will follow in whichthe results will be quality controlled and analyzed.A workshop to compare the results is tentativelybeing planned for autumn, 2006. For more informa-tion about ALMIP, see: http://www.cnrm.meteo.fr/amma-moana/amma_surf/almip/

References

Boone, A., F. Habets, J. Noilhan, D. Clark, P. Dirmeyer, et al.,2004. The Rhone-Aggregation Land Surface Scheme Intercom-parison Project: An Overview. J. Climate, 17, 187–208.

Dirmeyer, P. A., A. J. Dolman, and N. Sato, 1999. The GlobalSoil Wetness Project: A pilot project for global land surfacemodeling and validation. Bull. Amer. Meteor. Soc., 80, 851–878.

Henderson-Sellers, A., A. J. Pitman, P. K. Love, P. Irannejad,and T. Chen, 1995. The project for inter-comparison of land-surface parametrization schemes (PILPS): Phase 2 and 3. Bull.Amer. Meteo. Soc., 76, 489–503.

Koster, R. D., P. A. Dirmeyer, Z. Guo, G. Bonan, E. Chan, etal., 2004. Regions of strong coupling between soil moisture andprecipitation. Science, 305 (5687), 1138–1140.

Taylor, C. M., F. Said, and T. Lebel, 1997. Interactions be-tween the land surface and mesoscale rainfall variability duringHAPEX-Sahel. Mon. Wea. Rev., 125, 2211–2227.

US AMMA WORKSHOP4–5 May 2006

Washington, DC

The Workshop is being held to promote andcoordinate the US contributions to the AfricanMonsoon Multidisciplinary Analysis (AMMA)Project. The goal of the workshop is to de-velop a US strategy for addressing the keyscience issues related to the water cycle, land-surface-atmosphere interactions, and radiation(including the impact of aerosols). For moreinformation, see: http://www.ucar.joss.edu/amma.

US CONTRIBUTIONS TO THE2006 AMMA FIELD CAMPAIGN

Chris D. Thorncroft1, Peter J. Lamb2,and Paul Houser3

1SUNY at Albany, 2University of Oklahoma,3George Mason University

The AMMA field program builds on theCouplage de l’Atmosphère Tropicale et du CycleHydrologique (CATCH) experiment and providesenhancements to the current sustained observingsystem in West Africa. The Sahelian region hasone of the strongest soil moisture-precipitationfeedbacks in the world (Koster et al., 2004),indicating that improved soil moisture knowledgeis likely to yield improved prediction. Central tothe AMMA observing strategy are three mesositesthat sample contrasting environments across themarked north-south gradient in surface condi-tions, the so-called “climate transect” (see thefigure on page 1). Additional in situ observa-tions will be made at the mesosites and along theclimate transect to address science issues at lo-cal-to-regional scales. In addition, AMMA willprovide enhancements to the regional observingsystem over West Africa and in the Gulf of Guineaand the tropical Atlantic to support this analysis.The following describes the major US facilitiescontributing to the AMMA field program in 2006.

The US will support two major platforms atthe Niamey, Niger mesosite: (1) the Departmentof Energy Atmospheric Radiation Measurement(ARM) Program Mobile Facility (AMF); and (2)the National Aeronautics and Space Administra-tion (NASA) sponsored Massachusetts Instituteof Technology (MIT) C-band radar. The AMFincludes a comprehensive suite of instruments,including surface radiometers for both broadbandand spectrally resolved fields, standard surfacemeteorological measurements, and active instru-ments for probing the vertical structure of thetroposphere, including a 95 GHz cloud radar, amicropulse lidar, and radar wind profiler. TheAMF has been making measurements at the Niameyairport and at an ancillary rural site 60 km eastsince the beginning of January 2006 and will re-main deployed there for 1 year. It is a keyfacility of the Radiative Atmospheric DivergenceProject which uses the AMF, Geostationary EarthRadiation Budget (GERB) sensors, and AMMAstations. The measurements made by the suite ofinstruments available from the AMF along with

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measurements from research aircraft, GERB sen-sors, and the others will be used to examine theradiation budget of the atmospheric column. Par-ticular emphasis will focus on the effects of thehigh dust loadings during the dry season, andthe abundant water vapor during the summermonsoon season.

The MIT C-band Doppler radar will be de-ployed in Niamey for a minimum of 75 daysstarting in June 2006. The radar will providereflectivity and radial Doppler velocity in fullvolume scans at 10-minute intervals on a con-tinuous basis. Efforts are ongoing to deploy itfor an additional year to sample two consecutivesummers. The radar in Niamey will support analysisof: (1) convection including the ubiquitous in-tense Mesoscale Convective Systems (MCSs) inthis region; and (2) hydrology and land-surfaceinteractions. The analysis of the intense and elec-trically active MCSs will also be supported bythe Zeus lightning detection network that is nowoperating in the West African region (Chronisand Anagnostou, 2006).

Understanding the variability of the water cycleand associated rain-bearing systems in the twocontrasting mesosites in Niamey and Oueme (Benin)along the climate transect (see figure on page 1)is essential to improving our knowledge of theWAM. Both sites are supported by a uniquearray of hydrological and atmospheric measure-ments, and by precipitation measurements fromthe NASA Tropical Rainfall Measuring Mission(TRMM). These measurements will be supple-mented by two radars in the Oueme region(RONSARD and an X-band) provided by Eu-rope and two quadrilaterals of rawin soundingstations (akin to the intensive flux arrays in theTropical Ocean Global Atmospheres/CoupledOcean Atmosphere Response Experiment–TOGA-COARE) centred on Niamey and Oueme (figureon page 1) provided by Europe and Africa. Thislater network will provide high frequency sondelaunches to support the analysis of water, heatand momentum budgets.

The National Oceanic and AtmosphericAdministration's (NOAA) research vessel, theRonald H. Brown will perform two transectsduring the 2006 AMMA field campaign. Duringthe first transect, the French Tropical Atmo-sphere Ocean (TAO) Mooring, currently deployedat the equator, will be serviced and two addi-tional TAO Moorings will be deployed along thetransect ~5oN and ~12.5oN. In addition, oceanic

(e.g., surface and subsurface temperature, salin-ity and current observations) and atmospheric(e.g., rawinsondes and in situ thermodynamics)measurements will be made along this initial legto support the regional analysis of the WAM.The second leg will also be along 23oW from5oS to 20oN collecting oceanic and atmosphericobservations similar to those obtained during thefirst leg. These observations will support theregional analysis of the coupled WAM system aswell as the environment downwind from the WestAfrican coast. In particular, these data will sup-port the study of mechanisms that influence thetropical Atlantic upper layer heat content (includ-ing sea-surface temperature) and the Saharan AirLayer (SAL), both known to be important forsummer monsoon rainfall and tropical cyclonedevelopment.

NASA and NOAA aircraft will be coordi-nated to study the evolution of precipitatingconvective systems downwind from West Africa,largely as this evolution pertains to tropical cy-clogenesis. The NASA-AMMA (NAMMA-06)component will build on one or more airbornescience platforms, satellite sensors (e.g., TRMM),and ground-based instrumentation. The NASADC-8 high altitude research aircraft will serve asthe primary research tool for NAMMA-06 inves-tigations. The DC-8 will likely be based at theCape Verde Islands and may be flown in coor-dination with one or more NOAA HurricaneResearch Division (HRD) aircraft in the centraland eastern Atlantic basin. NASA also antici-pates conducting a surface-based scientificcomponent with its polarimetric weather researchradar (NPOL) and C-band Doppler weather radar(TOGA radar). Together, these radars will pro-vide an understanding of the transition ofconvective systems and their contributions totropical cyclogenesis as they move from conti-nental to marine environments. Other possibilitiesinclude the placement of the TOGA radar on theCape Verde Islands and the deployment of oneor more Aerosonde unmanned aerospace vehicles(UAVs) for continuous monitoring of the oceanicplanetary boundary layer and lower half of theSAL. The suite of ground-based measurementsin Cape Verde and Senegal will support the air-craft objectives on a continuous basis.

As part of the SAL Experiment (SALEX)investigations which began during the 2005 hur-ricane season, the NOAA HRD anticipatesdeploying the G-IV high altitude research aircraftand a single WP-3D Orion from Barbados in the

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Caribbean. These aircraft will be used to providein situ thermodynamic and kinematic profiles inand around developed African easterly waves(AEWs), tropical cyclones, and the SAL usinggeostationary positioning system dropsondes.

A driftsonde system was developed by theNational Center for Atmospheric Research (NCAR),primarily in response to needs of the WorldMeteorological Organization THORPEX (THe Ob-serving System Research and PredictabilityExperiment) (e.g., Shapiro and Thorpe, 2004).The effort is a technical collaboration betweenthe French Space Agency, CNES, providing theballooning expertise and NCAR providing thesounding (including deployment) expertise. Thedriftsonde operations during the AMMA SOPwill be based in N’dajamena, Chad with dailylaunches during periods of interest. This locationis well-suited to cover the West African regionas well as regions of hurricane genesis in thetropical Atlantic. Currently the driftsonde is fundedfor eight missions carrying 40 sondes each. ThisAMMA-THORPEX collaboration will be the firstdriftsonde research deployment and will be use-ful for several AMMA and THORPEX researchand forecast topics including: (1) characteriza-tion of the SAL and the ability of models torepresent its evolution, (2) numerical and obser-vational studies of the impact of dry air onconvection and tropical cyclogenesis, (3) inves-tigation into the interactions between convectionand African easterly waves, (4) studies of tropi-cal cyclone genesis and efforts aimed to extendthe accurate prediction of tropical cyclones inthe medium range, and (5) studies of the impactof targeted observations on weather systemprediction.

For more details about these platforms (in-cluding the Principal Investigators) and other UScontributions to AMMA (including the role ofNCEP) see the AMMA-US website at: http//www.joss.ucar.edu/amma. Information about plansfor the AMMA US workshop will also be madeavailable here (see page 11).

References

Chronis, T., and E. Anagnostou, 2006. Evaluation of a Long-Range Lightning Detection Network with Receivers in Europeand Africa. IEEE Transactions on Geoscience and RemoteSensing (in press).

Koster, R. D., et al., 2004. Regions of Strong Coupling Be-tween Soil Moisture and Precipitation. Science, 305, 1138–1140.

Shapiro, M., and A. Thorpe, 2004: THORPEX: A global atmo-spheric research programme for the beginning of the 21st century.WMO Bulletin, Vol. 54, No. 3.

TIGER INITIATIVE

Diego Fernández PrietoEuropean Space Agency

Following the 2002 Johannesburg World Sum-mit on Sustainable Development, the European SpaceAgency (ESA) launched the Terrestrial Initiative inGlobal Environment Research (TIGER), focusingon the use of space technology to supply water-related geo-information in support of integratedwater resource management for sustainable devel-opment in developing countries (with a particularfocus on Africa). TIGER consists of two majorelements: (1) a set of individual projects with lim-ited geographical coverage and scope, which are“building blocks” for the (2) political process,which aims at developing long-term, large-scale,sustainable information services for better decisionmaking in the water-resource management domain.

Since its initiation, TIGER has benefited from theassociation of the space and water resources-relatedprograms of the United Nations Educational Scientificand Cultural Organization (UNESCO) and other UnitedNations agencies (e.g., the UN Economic Commis-sion for Africa-International Water and Sanitation Centre;the Food and Agriculture Organization); other spaceagencies, international agencies; and key African or-ganizations [e.g., the African Ministerial Conferenceon Water, the Council for Scientific and IndustrialResearch (South Africa), the Department of WaterResources and Forestry (South Africa)].

TIGER projects span the African continent,and address the various stages of the water cycle,including the use of satellite data to map soilmoisture across Southern Africa, monitoring floodplains and humid zones in the Sahel region ofSenegal, combining radar and optical Earth obser-vation data to monitor the environmental state ofthe northwest coast of Madagascar, and modellingthe water balance of semi-arid rock watershedsusing both satellite imagery and in situ data.

TIGER is implemented through a number ofdevelopment and demonstration projects, research,training and capacity building activities. Throughthese activities the specific needs and demands forgeo-information by water managers are expressedby more than 150 African water authorities, univer-sities, environmental agencies and technical centers.

ESA projects operating under the TIGER um-brella reflect the TIGER priority topics of wetland

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monitoring, food security, epidemiology and ground-water resources management. Currently, 50TIGER-related projects are in progress, 70% ofwhich are being headed by African organizations.These projects include:

• Globwetland – provides satellite data on 15African wetland sites—important for protect-ing biodiversity, moderating flooding andmaintaining water purity—with ten differentAfrican governments among the project users.Products include land cover and land usechange maps on the scale of individual wet-land sites and drainage basins in support ofreporting obligations for the internationalRamsar Convention on Wetlands.

• Global Monitoring for Food Security(GMFS) – employs Earth observations tomaintain a continental-scale overview of sub-Saharan Africa to produce subnational andselected high-resolution crop production fore-casts for African agricultural ministries andnongovernmental organizations.

• Epidemio – uses satellites to provide envi-ronmental information in the service ofepidemiology, including the charting of waterbodies to prepare malaria risk maps for userssuch as the World Health Organization.

• Rivers and Lakes Project – developed asystem for authorities that monitors levels forrivers and lakes.

• Aquifer Project – generates products andservices related to the management of groundwater-storing subsurface aquifers, a crucialsource of fresh water in North Africa. Theseinclude land-use cover and land use changecharts, digital terrain maps, soil moisture mappingand subsidence monitoring to help identifyand encourage the use of new and existing

aquifers in a sustainable manner. Users in-clude the governments of Algeria, Libya, Mali,Niger, Nigeria and Tunisia.

A TIGER Workshop was held at the EuropeanCentre for Earth Observation in Frascati, Italy on3–4 October 2005, followed by 3 days of Earthobservation technology training sessions. Ninety-fiveparticipants from 31 countries attended the workshopto review the status of TIGER-related projects inprogress. Existing activities have now been bolsteredby new project types called “TIGER Innovators”started by ESA in December 2005. These projectsare aimed at developing innovative, low-cost solu-tions to support African water authorities in theconservation and monitoring of scarce water resources.Utilizing the latest Earth observation technologies andgeographical information systems, these partnershipsinvolving European/Canadian and African organiza-tions will tackle a range of different water-relatedissues across the African continent.

Several major developments were reported at theworkshop. Dr. Stephen Donkor, UN Economic Com-mission for Africa (UNEC-A), Chairman of the TIGERSteering Committee, reported that UNEC-A is hostingan Africa Water Information Clearing House intendedto be a “one-stop shop” for all available data onAfrican water, which will be made available to every-one who needs it. Results from individual TIGERprojects will be added to this Clearing House on thebasis that increasing their visibility and data accessi-bility will increase their overall effectiveness. It shouldalso be a means of attracting funding from nationaland international funders to support the continuationof TIGER project activities. Dr. Jean-Marc Chounard,Canadian Space Agency (CSA), reported that theseven projects being supported by CSA would all bereceiving free Radarsat-1 data, including a high-reso-lution radar mosaic of the African continent.

In conclusion, there is no doubt that the manage-ment of water resources will pose a major challengein this century, particularly as the growth in the globalpopulation is greatest in regions with dry and semi-dry climates. With its TIGER initiative, ESA isaddressing this challenge head-on by fostering a greaterunderstanding of the water cycle, and by providingcrucial information to decision makers at local, re-gional and global levels. Improved information aboutthe use of water resources not only provides a betterbasis for life and health to local people, but is alsoa critical factor in supporting peace and stabilityamong countries desperately concerned about the useof shared water resources. For more information, see:http://www.tiger.esa.int.

Girls at the water source. (Photo Credit: ESA)

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GLOBAL SURFACE ALBEDO DERIVEDFROM GEOSTATIONARY SATELLITES

Yves Govaerts1, Alessio Lattanzio2, andJohannes Schmetz1

1EUMETSAT, Germany, 2MakaluMedia, Germany

The albedo of the Earth’s surface determines thepartition between the solar radiation reflected back tothe atmosphere and absorbed at the surface, and thuslargely determines the surface energy balance. Veg-etation type and amount play a significant role in thetemporal and spatial variability of surface albedo.Climate models show a positive feedback betweensurface albedo and precipitation in large subtropicalregions like the Sahel where an increase in surfacealbedo implies a reduction in rain rates, which in turnleads to vegetation removal, thus reinforcing highsurface albedo values.

Although the potential of space-based observa-tions for mapping global surface albedo has longbeen recognized, these observations have only beenroutinely retrieved since 2001 from the ModerateResolution Imaging Spectroradiometer (MODIS) andMulti Angle Imaging Spectroradiometer (MISR) onTerra. This is partly due to the limited number ofspace instruments dedicated to land-surface observa-tions before the late 1990s when systematic space-borneobservations were essentially limited to data acquiredby geostationary meteorological satellites and a fewpolar platforms. Recently EUMETSAT demonstratedthat surface albedo can be derived in a consistentmanner from geostationary satellites located at regularintervals around the Equator (see figure on page 20)by using archived satellite observations (Govaerts etal., 2004a) in conjunction with state-of-the-art retrievaltechniques (Pinty et al., 2000). The consistency ofthis global product has been thoroughly verified bycomparing surface albedo values over common areasobserved by two adjacent satellites (Govaerts et al.,2004b). Pinty et al. (2005) demonstrated that surfacealbedo derived from geostationary satellites comparesfavorably with MODIS or MISR observations.

The possibility to consistently and accuratelygenerate such a product is very encouraging sincedata from the corresponding geostationary satellitearchives cover more than two decades and thusoffer a unique opportunity to derive long-term datasets of surface albedo for climate studies. Thesewill provide new insights into climate and vegeta-tion variability. In particular, the Meteosat archive,whose images encompass the African continent forthe last 25 years, permits the monitoring of seasonal

surface albedo changes in sensitive regions such asthe Sahel where interannual relative differences aslarge as 10 percent are observed (see figure below).It will also shed new light on important questionsconcerning the hydrological cycle and its interactionwith surface albedo as already demonstrated by Knorret al. (2001).

Interannual variations of surface albedo seasonal cycleover a region ranging from 8°W to 8°E and 0° to12°N. Solid line is for year 2000, dashed line 2001,and long-dashed line 2003.

This pilot study, conducted at EUMETSAT incollaboration with the European Union Joint ResearchCentre in the framework of a Coordination Group forMeteorological Satellites request and a Global ClimateObserving System recommendation, demonstrates thatgeostationary satellite data archives hold promise forrelevant, yet untapped information on our climatesystem. The new information will be useful for long-term monitoring of the climate system as it potentiallycovers already more than two decades. The studyalso demonstrates the utility of archived data frommeteorological satellites for climate studies.

References

Govaerts, Y. M., M. Clerici, and N. Clerbaux, 2004a. OperationalCalibration of the Meteosat Radiometer VIS Band. IEEE Trans-actions on Geoscience and Remote Sensing, 42, 1900–1914.

Govaerts, Y., A. Lattanzio, B. Pinty, and J. Schmetz, 2004b.Consistent surface albedo retrieval from two adjacent geostation-ary satellites. Geophys. Res. Lett., 31, doi:10.1029/2004GL020418.

Knorr, W., K.-G. Schnitzler, and Y. Govaerts, 2001. The Roleof Bright Desert Regions in Shaping North African Climate.Geophys. Res. Lett, 28, 3489–3492.

Pinty, B., F. Roveda, M. M. Verstraete, N. Gobron, Y. Govaerts,et al., 2000. Surface albedo retrieval from Meteosat: Part 1:Theory. J. Geophys. Res., 105, 18099–18112.

Pinty, B., M. Taberner, S. Liang, Y. Govaerts, et al., 2005.MODIS/Meteosat/MISR Surface Albedo Comparison Results.9th International Symposium on Physical Measurements andSignature in Remote Sensing (ISPMSRS), Beijing, China, 17–19October 2005.

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GEWEX RELEVANT PUBLICATIONSOF INTEREST

Monitoring the Response of VegetationPhenology to Precipitation in Africa by

Coupling MODIS and TRMM Instruments

Reference: X. Zhang, M. A. Friedl, C. B.Schaaf, A. H. Strahler, and Z. Liu. J. Geophys.Res., Vol. 110, D12103: 2005.

Summary/Abstract: While temperature controls onvegetation phenology in humid temperate climateshave been widely investigated, water availability isthe primary limit on vegetation growth in arid andsemiarid ecosystems at continental and global scales.This paper explores the response of vegetationphenology to precipitation across Africa from 2000–2003 using vegetation index data from theModerate-Resolution Imaging Spectroradiometer (MO-DIS) and daily rainfall data obtained from theTropical Rainfall Measuring Mission (TRMM). Theresults indicate that well-defined thresholds exist incumulative rainfall that stimulate vegetation green-up in arid and semiarid regions of Africa.

Influence of Surface Processes over Africaon the Atlantic Marine ITCZ and

South American PrecipitationReference: S. M. Hagos and K. H. Cook.2005. J. Clim., Vol. 18, No. 23, pp. 4993–5010.

Summary/Abstract: Previous studies show that theclimatological precipitation over S. America, particu-larly the Nordeste region, is influenced by the presenceof the African continent. The influence of Africantopography and surface wetness on the Atlantic ma-rine ITCZ (AMI) and S. American precipitation areinvestigated. Cross-equatorial flow over the AtlanticOcean introduced by north–south asymmetry in sur-face conditions over Africa shifts the AMI in thedirection of the flow. African topography, for ex-ample, introduces an anomalous high over the southernAtlantic Ocean and a low to the north. This resultsin a northward migration of the AMI and dry condi-tions over the Nordeste region. The implications ofthis process on variability are then studied by analyz-ing the response of the AMI to soil moisture anomaliesover tropical Africa. Northerly flow induced by per-turbations in soil moisture over northern tropical Africashifts the AMI southward, increasing the climatologi-cal precipitation over northeastern S. America. Flowassociated with an equatorially symmetric perturba-tion in soil moisture, however, has a very weakcross-equatorial component and very weak influenceon the AMI and S. American precipitation.

Investigation of Hydrological Variability inW. Africa Using Land Surface Models

Reference: K. Y. Li, M. T. Coe, and N. Ramankutty,2005. J. Clim., Vol. 18, No. 16, pp. 3173–3188.

Summary/Abstract: In this study, a land surfacemodel, the Integrated Biosphere Simulator (IBIS),and a hydrological routing model, the HydrologicalRouting Algorithm (HYDRA), are used to investigatethe hydrological variability in two large basins, theLake Chad basin (LCB) and the Niger River basin(NRB), located in W. Africa, over the period from1950 to 1995. The results show that the hydrology inthis area is highly variable over time and space. Thecoefficient of variance (CV) of annual rainfall rangesfrom 10%–15% in the southern portions of the ba-sins to 30%–40% in the northern portions. The annualevapotranspiration (ET) varies with a slightly lowerCV compared to the rainfall, but the runoff is ex-tremely sensitive to the rainfall fluctuation, particularlyin the central portions of the basins (8°–13°N in LCBand 12°–16°N in NRB) where the CVs in runoff areas high as 100%–200%. The annual river dischargevaries largely in concert with the rainfall fluctuation,with the CV being 37% in LCB and 23%–63% inNRB. In terms of the whole basin, the relative hydro-logic variability (rainfall, ET, runoff, and river discharge)is significantly higher in the dry period.

Evaluating the NCAR Climate System ModelOver W. Africa: Present-day and the

21st Century A1 Scenario

Reference: A. F. Kamga, G. S. Jenkins, A. T.Gaye, A. Garba, A. Sarr, and A. Adedoyin, 2005.J. Geophys. Res., Vol. 110, D03106.

Summary/Abstract: An analysis of observed and simu-lated June–July–August W. African climate during thelast 2 decades of the 20th and 21st centuries is pre-sented. The National Center for Atmospheric Researchcoupled atmosphere-ocean climate system model (CSM)simulation is compared to long-term observations andNational Centers for Environmental Prediction reanalysiswith an emphasis on the wet season during the late 20thcentury. While there are significant improvements in thesimulation of the African Easterly Jet and African easterlywaves relative to the uncoupled Community ClimateModel, Version 3, biases still exist. These biases arerelated to a poor simulation of the Azores high, whichextends into E. Europe, allowing for cold air advectioninto N. Africa. There is also little improvement in theupper troposphere Tropical Easterly Jet in the CSM,which is too weak and does not extend westward overthe Atlantic Ocean.

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GLASS/GABLS WORKSHOP ONLOCAL LAND-ATMOSPHERE COUPLING

19–21 September 2005De Bilt, The Netherlands

Bart van den Hurk1, Bert Holtslag2, andChristian Peters-Lidard3

1KNMI, 2Wageningen University, 3NASA/GSFC

The Global Land-Atmosphere System Study(GLASS)/GEWEX Atmospheric Boundary LayerStudy (GABLS) Workshop on Local Land-Atmo-sphere Coupling provided a wide range of newscientific insights in the mutual interaction betweenthe land-surface and the atmospheric boundary layer.Highlights from the workshop are presented here.

Land-atmosphere interactions for stable boundarylayer (BL) conditions were decribed by Gert JanSteeneveld who presented encouraging results from acoupled land-atmosphere 3-day simulation using theCooperative Atmosphere-Surface Exchange Study-1999(CASES-99). His work suggests that a simple set ofsurface energy balance equations is well suited fordescribing the role of an interactive surface-planetaryBL system. Michael Ek presented the derivation andapplicability of a general relative humidity tendencyequation (see Ek and Holtslag, 2004). This equationmay be used as a diagnostic tool to quantify therelative contributions of surface moisture conditions,atmospheric stratification and boundary layer growthin the formation of BL clouds. Frank Beyrich illus-trated the use of the Lindenberg InhomogeneousTerrain–Fluxes between the Atmosphere and Surface,a long-term Study (LITFASS) measurements for studyingthe role of land-surface heterogeneity on land-atmo-sphere interaction as well as BL studies.

Luis Bastidas demonstrated the impact of land-atmosphere coupling in the process of parametercalibration. Optimal values of parameters both in theland and the atmospheric components of a coupledsingle column land-atmosphere model were quite dif-ferent, depending on the whether the land-only or thecoupled system was used to optimize the parametervalues. Eleanor Blyth and Richard Essery presentedthe Joint UK Land Environment Simulator (JULES)infrastructure, which may be integrated into the Na-tional Aeronautics and Space Administration (NASA)Land Information System.

Land-atmosphere interaction diagnostics derivedfrom large-scale model experiments were reviewed.Paul Dirmeyer compared the Global Land-AtmosphereCoupling Experiment (GLACE) coupling strength to

the measured response of surface fluxes to soil mois-ture. He concluded that in contrast to observations,the GLACE models tend to give a stronger relation-ship between evaporation and soil moisture than betweenevaporative fraction and soil moisture. Also, the strengthof the link between sensible heat flux and soil mois-ture is generally underestimated in the models. AntonBeljaars reported on analyses by Alan Betts, andmade a plea for scientists to compare model outputto observable quantities that express various couplingprocesses in the land-atmosphere system, in particu-lar net longwave radiation and diurnal temperaturerange for coupling aspects under stable conditions,and cloud albedo, lifting condensation level and BLrelative humidity in daytime conditions.

In addressing data assimilation methodologies,Dara Entekhabi reported that: (1) these techniques,when applied to relatively simple coupled land-atmosphere models, are very helpful in extractingrelevant information on coupling processes, as theyallow the explicit formulation of errors in both theobservations and models; and (2) remotely sensedsurface temperatures that are readily available in alarge range of spatial and temporal resolutions,could be used to define the actual state of the landsurface and overlying atmosphere, such as thespatial distribution of the aerodynamic exchangecoefficient.

Joseph Santanello, Jr. showed the value of highresolution profiling instruments, the NASA Atmo-spheric Infrared Sounder (AIRS) and the ModerateResolution Imaging Spectroradiometer (MODIS), indetermining the likelihood of a dry-down feedbackcycle. When soil conditions are already dry, a deepnocturnal residual layer allows for a rapid boundarylayer growth and thus ventilation after sunrise, pro-moting a rapid removal of evaporated moisture. Someof the conclusions and recommendations resultedfrom the Workshop include the following:

CASES-99• In view of the difficulty in collecting data to

show differences between modelled and truestates, it was recommended that LES simula-tions be carried out for a (series of) completediurnal cycle(s) that would serve as referencefor future observational campaigns.

• The set of meaningful diagnostic evalua-tions should be extended following the linesof the recent work of Alan Betts (e.g.,inspection of net longwave radiation, parti-tioning between soil and sensible heat, diurnaltemperature range).

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• Current CASES-99 simulations should berepeated with models in which surface tem-perature is not prescribed but has morefreedom to vary, thereby explicitly account-ing for interactive land-atmosphere coupling.Rather than including a complex land sur-face scheme, a simple set of (calibrated)surface energy balance equations is recom-mended, for its ease of implementation inparticipating schemes, and its ease for stan-dardizing among the participating models.

Hydrological coupling• Single column integrations should be con-

ducted in a different number of locations,both within and outside the so-called GLACEidentified “hotspots.” These integrationsshould examine the causes of differences incoupling strengths among large-scale mod-els and between models and observations.

• Ek and Holtslag’s RH-tendency equationshould be extended to include the relativecontribution of lateral advection and possi-bly other diagnostics that express the presenceof a residual layer or vegetation stress regime.

General recommendations• The extension of uncoupled with coupled

simulations helps to increase the understand-ing of the role of coupling in the processesseen in nature. It also reveals possiblephenomena not emerging in uncoupled simu-lations. However, prior to carrying out aseries of simulations, it is advisable to: (1)define a null-hypothesis to the experiments;(2) define the diagnostics to be examined;and (3) do the simulations with well-definedstandardized interfaces.

• Simple data assimilation models and diagnosticsshould be used to extract relevant informationfrom both observations and model equationsbecause they avoid long integrations and providebetter inputs to experimental designs.

References

Ek, M. B., and A. A. M. Holtslag, 2004. Influence of SoilMoisture on Boundary Layer Cloud Development. J. Hydrom-eteor, Vol. 5, No. 1, pp. 86–99.

Steeneveld, G. J., B. Vd Wiel, and A. Holtslag, 2005. Modellingthe evolution of the atmospheric boundary layer coupled to theland surface for three contrasting nights during CASES99;J. Atmos. Sci. (accepted).

Trier, S., F. Chen, and K. Manning, 2004. A Study of convec-tion initiation in a mesoscale model using high-resolution landsurface initiation conditions. Mon. Wea. Rev., 132, 2954–2976.

The Third Session of the GEWEX RadiationPanel Working Group on Data Management and Analysis(WGDMA) was hosted by EUMETSAT. Topics cov-ered at the meeting included data project and datacenter status and readiness to continue operations for2006–2010 and the data product assessment activi-ties. Other topics discussed were the identification ofimprovements to the data products and plans for acoordinated product reprocessing. Related data prod-uct activities and plans for analyses of the globalenergy and water cycle were also discussed.

The following improvements to the Global Pre-cipitation Climatology Project (GPCP) data productswere proposed: (1) substitute the Global PrecipitationClimatology Centre 50-year gauge analysis for theoriginal product to improve record homogeneity; (2)adjust the results for topographic altitude; (3) replacethe microwave radiance data with a more homoge-neous version and modernize the microwave algorithm;(4) anchor the microwave products to the TropicalRainfall Measuring Mission data; (5) increase timeresolution in the earlier products using the denserinfrared radiance product from the International Sat-ellite Cloud Climatology Project (ISCCP) (B1U); (6)consider the possibility of obtaining and using dailyrain gauge data; and (7) implement new snow retrievalmethods as part of the analysis using ancillary sur-face air temperature data to discriminate between rainand snow.

Proposed improvements to the ISCCP data prod-ucts included: (1) refine detection of polar clouds; (2)refine treatment of ice clouds and land and ice sur-faces; (3) reduce the satellite viewing angle dependencein the results; (4) switch processing from B2 to theB1U radiance data set; (5) process all overlappingdata; and (6) release a global DX product and a DSproduct and consider producing a daily product.

Recommendations for improving the Surface Ra-diation Budget (SRB) Project data products included:(1) use a uniform atmospheric temperature and hu-midity data set for the entire record; (2) improve thetrace gas climatology and use the Stratospheric Aerosoland Gas Experiment (SAGE) and GACP data for

3RD SESSION OF THE WGDMA

14–17 November 2005Darmstadt, Germany

William B. RossowNASA Goddard Institute for Space Science

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aerosol records; (3) use recent products to improvesurface albedo and emissivity spectral and seasonaldependence; (4) consider processing all available sat-ellite pixels in a grid box rather than using currentsatellite hierarchy; (5) evaluate clear-sky composite-based values of surface albedo and temperature; (5)refine cloud emissivities and day-night difference treat-ment; (6) implement new Clouds and Earth’s RadiantEnergy System angle dependence models and refineoptical properties for aerosol and ice clouds; and (7)evaluate cloud layer thickness, overlap and cloud baselocation treatments.

Improvements proposed for the Global AerosolClimatology Project (GACP) data products included:(1) develop and implement a retrieval procedure overland; (2) evaluate differences among satellite aerosolproducts to “calibrate” long-term products; and (3)merge aerosol and cloud products to facilitate study ofaerosol indirect effects.

Actions recommended for a coordinated repro-cessing of all the products included: (1) complete theproduct assessments to identify problems and sug-gest improvements with a focus on improvedhomogeneity of the time record; (2) coordinate thereview of all radiance calibrations and adopt commonresults for all projects; (3) evaluate available ancillarydata sets describing the properties of the atmosphereand surface and adopt a common set for all projects;(4) exploit interdependencies using SAGE and GACPas input for ISCCP, and using SAGE, GACP andISCCP as inputs for SRB and GPCP; (5) implementrefinements to increase space-time sampling intervalstowards a common goal of at least 100 km, daily (3-hourly if possible); and (6) develop at least oneproduct from all projects that has a common mapgrid interval and time step.

The WGDMA members proposed the followingmilestones to meet their GEWEX Phase II Plan objectiveto produce long-term research quality data sets for thestudy of the global energy and water cycle.

2006: Release current products as a package2006: Complete review of radiance calibrations2007: Complete first analyses of global energy-

water cycle with current products2007: Complete data product assessments2008: Complete reprocessing of precipitation, aero- sols, cloud, and radiation products2009: Complete improved SeaFlux products and the new LandFlux products2010: Complete second product assessment2011: Complete second global analyses

GEWEX/WCRP MEETINGS CALENDARFor a complete listing of meetings, see the

GEWEX web site (http://www.gewex.org)6–11 March 2006—27TH SESSION OF THE WCRP JOINTSCIENTIFIC COMMITTEE, Pune, India.

13–17 March 2006—WORKSHOP ON THE ORGANIZA-TION AND MAINTENANCE OF TROPICAL CONVECTIONAND THE MADDEN JULIAN OSCILLATION, Trieste, Italy.

13–18 March 2006—ESA SYMPOSIUM–15 YEARS OFPROGRESS IN RADAR ALTIMETRY, Venice, Italy.

16–22 March 2006—FOURTH WORLD WATER FORUM:LOCAL ACTIONS FOR A GLOBAL CHALLENGE, MexicoCity, Mexico.

20–22 March 2006—1ST GEWEX RADIATION PANELAEROSOLS WORKSHOP, College Park, Maryland, USA.

21–24 March 2006—2006 NOAA CLIMATE PREDIC-TION APPLICATIONS SCIENCE WORKSHOP, Tucson,Arizona, USA.

23–24 March 2006—GLOBAL WATER SYSTEMPROJECT SSC MEETING, Oaxaca, Mexico.

28–29 March 2006—WORKSHOP ON THE DEVELOP-MENT OF A GLOBAL IN-SITU SOIL MOISTURE NETWORK,Noordwijk, The Netherlands.

2–7 April 2006—EGU 2006 GENERAL ASSEMBLY,Vienna, Austria.

19–21 April 2006—WORKSHOP ON ASSESSMENTOF GLOBAL CLOUD CLIMATOLOGY PRODUCTS, Ft.Collins, Colorado, USA.

19–22 April 2006—CLIVAR SSG-14, De Bilt, TheNetherlands.

4–5 May 2006—US AMMA WORKSHOP, Washington,DC, USA.

22–23 May 2006—ASSESSMENT OF CLIMATE CHANGEFOR THE BALTIC SEA BASIN, Goteborg, Sweden.

23–26 May 2006—AGU, GS, MAS, MSA, SEG, AND UGM2006 JOINT ASSEMBLY, Baltimore, Maryland, USA.

4–8 June 2006—5TH BALTEX STUDY CONFERENCE,Island of Saaremaa, Estonia.

6–9 June 2006—WCRP WORKSHOP ON UNDERSTAND-ING SEA-LEVEL RISE AND VARIABILITY, Paris, France.

12–15 June 2006—SPARC-GEWEX/GCSS-IGAC WORK-SHOP: MODELLING OF DEEP CONVECTION AND ITSROLE IN THE TROPICAL TROPOPAUSE LAYER, Victoria,BC, Canada.

20–22 June 2006—1ST WORKSHOP ON REMOTE SENS-ING AND MODELLING OF SURFACE PROPERTIES,Paris, France.

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Broadband surface albedo as derived at EUMETSAT from observations acquired by Meteosat-5and -7, GOES-8 and -10, and GMS-5 for the period of 1–10 May 2001. See article on page 15.

GEWEX NEWSPublished by the International GEWEX Project Office (IGPO)

Richard G. Lawford, DirectorEditor: Dawn P. ErlichInternational GEWEX Project Office1010 Wayne Avenue, Suite 450Silver Spring, MD 20910, USA

Assistant Editor: Carolyn S. SereyTel: (301) 565-8345Fax: (301) 565-8279E-mail: [email protected] Site: http://www.gewex.org

SURFACE ALBEDO DERIVED FROM GEOSTATIONARY SATELLITES

AMMA ADDRESSES THE MULTIPLE TIME SCALES THATCHARACTERIZE THE WEST AFRICAN MONSOON

The key phenomena and associated spaceand time scales to be addressed by theAfrican Monsoon Multidisciplinary Analy-sis (AMMA) Project. The arrow highlightsthe importance of scale interactions andtransport processes in the West AfricanMonsoon. See article on page 5.