January 2005

7

CEOP Phase I successes must be sustained through a CEOP Phase II effort for climate
research and Earth observations: A view by the Director of the World Climate Research Programme (WCRP)International Global Energy and Water Cycle Experiment (GEWEX) Project Office and Executive Chair of the Integrated
Global Water Cycle Observations (IGWCO) theme of the Integrated Global Observing Strategy Partnership (IGOS-P)
Richard Lawford, Director, International GEWEX Project Office (IGPO), MD, USA

It is a privilege to have an
opportunity to offer a perspectiveon CEOP at this critical point as it
transitions from Phase I to Phase
II. The first phase of CEOP has
made important steps towards
the realization of its long-term
Richard (Rick) Lawford
scientific goal – to understandand model the influence of continental hydroclimate processeson the predictability of global atmospheric circulation andchanges in water resources, with a particular focus on the heatsource and sink regions that drive and modify the climate system and anomalies. I am sure that those who are close to
CEOP, however, would be the first to recognize that there is agreat deal more that needs to be done.
CEOP has made remarkable progress since it was initiated by
the Global Energy and Water Cycle Experiment (GEWEX) within
the framework of the World Climate Research Programme(WCRP) in 2001. As Director of the International GEWEX Project
Office (IGPO), I have closely followed the progress of CEOP
because its scientific and technical goals are synergistic withthose of GEWEX. Not only has CEOP been successful in developing comprehensive composited datasets, it also has stimulated a number of research projects that continue to advance ourunderstanding of processes important for climate prediction. In
addition, CEOP reports indicate that a number of milestones
have been reached in each of the main CEOP science focal
areas.
CEOP’s synergy with GEWEX goals is evident through its primary science focuses including land surface processes andmonsoons. For example, the Water and Energy Simulation andPrediction (WESP) Working Group has been using enhanced
observations to diagnose, simulate, and predict water and energy fluxes and reservoirs over land on diurnal to annual temporalscales as well as to apply these predictions for water resource
applications. In addressing this goal, which interacts very effectively with the GEWEX Water and Energy Budget studies, the

CEOP Monsoon Systems Working Group has taken steps to document the seasonal march of the monsoon systems, assess
their driving mechanisms, and investigate the possible connections between monsoonal systems in different regions. The
CEOP Inter-monsoon Model Study (CIMS), which has spurred theorganization of a Pan-WCRP Monsoon Studies Workshop, is unifying studies of these important climate phenomena that occur
in different regions of the world.
In my recent role as the co-chair of the writing team for the
IGWCO and my present role as the Executive Chair of the
Implementation team, I have come to appreciate CEOP’s contributions to IGWCO and plans for new approaches to Earth observations based on paradigms such as interoperability, integration,and timeliness. CEOP’s success in bringing together space
agencies, the research community, tower operators, andNumerical Weather Prediction and Data assimilation centers has
provided a model for addressing complex scientific and observational issues. As IGOS-P and the Committee of Earth Observing
Satellites (CEOS) have witnessed CEOP’s ability to build a community and to harness the energies of diverse groups including
research scientists and operational forecasters, they havegained confidence in the water cycle science community and its
ability to achieve the ambitious plans that relate to the IGWCO
implementation plans and the targets described for the watersector in the Global Earth Observation System of Systems(GEOSS) Ten-Year Implementation plan. Given CEOP continuingContents:• A View of CEOP by the Director, IGPO and Executive Chair,
IGWCO• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1,2• Summary of the American Monsoon System Workshop(Montevideo, Uruguay, 17-18 September 2004) • • • • • • • • 2• Summary of the CEOP International Metadata Meeting(Tokyo, Japan 1 - 2 November 2004) • • • • • • • • • • • • • • • • • • • • 3• Summary of CEOP Issues Presented at the Joint Meeting of
WGNE and GMPP (Exeter, UK, 11-15 October 2004) • • • 4• Proposed CEOP Model Inter-comparison Experiment
Framework • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 4,5• Preliminary results from the CEOP Inter-Monsoon
Studies(CIMS) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 5,6,7• Contribution of the CATCH project to the CEOP • • • • • • • 8

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CEOP Newsletter No.7

leadership in data intergration, it is fully understandable that
IGOS-P has endorsed CEOP II as a central IGWCO activity.
The decision to extend CEOP into a Phase II (2005-2010),
which was made by the CEOP Advisory and OversightCommittee (AOC) and CEOP Science Steering (SSC) Committee,
has also been endorsed by the GEWEX Scientific Steering Group(SSG) and the Joint Steering Committee of the World Climate
Research Programme (WCRP). This transition is timely because
GEWEX and CEOP are both contributing to the establishment of
the WCRP Coordinated Observation and Prediction of the Earth
System (COPES) strategy as a unifying and integrating strategic
framework for making more effective use of the capabilities of
the climate research community and the growing capabilities ofobservation, data assimilation, and prediction systems.

positive contribution to the overall context of water and energy
cycle research in climate studies. It is important to researchcommunities of WCRP and GEWEX, and to Earth observation
communities in IGOS-P and CEOS that CEOP remains a stable,
well-funded activity so that its participants can focus on its scientific and system development goals. While all space agencies
are to be commended for their support the Japanese Aerospace
Exploration Agency (JAXA) and the National Aeronautical Space
Agency (NASA) have been exemplatory in this respect. I would
also be remiss without recognizing a few of the central individuals, such as the Chief CEOP scientists, the International CEOP
coordinator, the CEOP Secretariat and the leads of the Scientificand Data Working Groups, that have made CEOP a successthrough their unselfish commitment to its objectives. The commitment of past experts as well as new participants is welcome
and indeed is essential for the success of Phase II of CEOP.

The programmatic, technical, and scientific infrastructure thathas evolved in CEOP over its initial observation period is a very

Summary of Discussions at the American Monsoons System Workshop (Montevideo,
Uruguay, 17-18 September 2004): Held as the Third In a Series of CEOP Inter-monsoon Model
Study (CIMS) Monsoon Science Meetings
Jose Marengo, CPTEC/INPE, Sao Paulo, Brazil

The Third CEOP Workshop on Monsoon Systems associated with
CEOP Inter-monsoon Model Study (CIMS) was organized in cooperation
with the World Climate Research Programme (WCRP) and Global Energy
and Water Cycle Experiment (GEWEX) Hydrometeorology Panel. Local
support was received from the Universidad de la Republica fromMontevideo, Uruguay. The meeting was organized by Dr. Jose A.
Marengo, from the Centro de Previsão de Tempo e Estudos Climáticos(CPTEC) from Sao Paulo, Brazil, who co-chaired the proceedings with Dr.
Roberto Mechoso from the University of California-Los Angeles (UCLA), at
California, USA.
The main objective of the meeting, which the participants agreed was
successfully accomplished, was to provide better understanding of fundamental physical processes underpinning the diurnal and annual
cycles, and intraseasonal oscillations in monsoon land and adjacentoceanic regions especially of the Americas, and also of Africa, Asia, andAustralia; as well as to share experiences and ideas on studies ofprocesses and variability in the American, Asian (Indian and Australian)and African monsoons. Progress was made toward the accomplishmentof each of a number of specific issues, which motivated the organizationof the meeting, including to:- identify individuals and institutions working on different aspects ofmonsoon studies in the Americas;- encourage the use of data from field experiments and reference sites
for observational and modeling studies for both North American
Monsoon Systems (NAMS) and South American Monsoon Systems(SAMS);- encourage collaboration among scientists on monsoon issues, relevantto the objectives of other international monsoon activities such as the
WCRP Climate Variability and Predictability (CLIVAR) Project, Variabilityof American Monsoon Systems (VAMOS) initiative; the CLIVAR AsianAustralian Monsoon Panel; WCRP Global Energy and Water Cycle
Experiment (GEWEX) monsoon related studies and CEOP Monsoon
Working Group research.
Over 25 presentations were made by a large International Group ofmulti-displinary researchers. The focus was on processes, studies onmodel physics improvement, simulations, and cross-validation of global
and regional model outputs with talks on detailed observational analyses
using in-situ observations and gridded CEOP model datasets.
Assessments of model capabilities in simulating physical processes in
the America’s monsoon and inter-comparisons with the Asian monsoon
were also presented. Observational studies were described that had
been undertaken to understand the intraseasonal, interannual anddecadal time scale variability of the monsoon in the Americas. Other
talks covered issues related to the water and energy balances, diurnal
cycle, predictability, teleconnections and regional forcing in monsoon
regions. New research that included aerosol interactions with monsoon
systems were also presented. Recent studies done as part of the
GEWEX Large-scale Biosphere-Atmosphere Experiment in Amazonia(LBA) have linked the concentration of aerosols due to biomass burningin the Amazon with rainfall and the onset of the rainy season in southern
Amazonia.

CEOP Newsletter No.7

Summary of the CEOP International Metadata Meeting(Tokyo, Japan 1 - 2 November 2004)
Sam Benedict, CEOP International Coordination Function, CA, USA

A meeting was held in Tokyo in early November 2004 that focused on
the establishment of a unified CEOP Metadata format. The International
specialists at the meeting agreed that a CEOP metadata design was necessary for integrating CEOP satellite imagery, reference site data andsimulation result data. This effort is necessary for CEOP to meet its
commitments to the CEOS IGOS-P, IGWCO, to WCRP COPES and ultimately to the implementation of GEOSS, by enabling interoperability ofmultiple systems (beyond those currently defined as part of CEOP) andby developing metadata services incorporating international standards as
one of the main activities of CEOP.
The participants agreed that the role of metadata in CEOP will be to:- Provide data producers with appropriate/consistent
information/requirements.
- Facilitate organization and management of the CEOP datasets.
- Enable users to apply geographic data.
- Facilitate data discovery, retrieval and reuse.
- Enable users to determine whether geographic data in a holding will beof use to them.

Because there are existing standards for metadata, such as ISO
19115, for geographic Information the main task is to harmonize the
CEOP metadata with the ISO metadata. This requires that a metadata
standard/design must be devised for CEOP satellite, reference site, GRIB
Model output and MOLTS model output data types. Presentations at themeeting showed that work has already begun on this task and metadata
designs have been prototyped for each CEOP data type. For the satellitedata, the AMSR-E instrument was chosen as an illustrative example forthe metadata structure. The AMSR-E product consists of a header and adata part and the header includes the core metadata and the productmetadata. As an example, one part of the metadata standard format for
CEOP satellite data (specifically for the AMSR-E, instrument) was shownat the meeting (see Figure 1.). Other similar examples already exist for
the CEOP in-situ and model data types.
The CEOP Lead Scientist noted that the plans for implementation of a
CEOP metadata standard established by the participants require
endorsement by CEOS and commitments by space agencies, especially
JAXA and NASA, to be achieved. Strategies are being developed toobtain the required support.

Header information of data and their mapping to ISO metadata (1)header data
Index CEOP
item description

ISO metadata
package
Identification
Information

Class

1

Filename

2

Sensor

MD_Sensor

3

Product

MD_DataIdentification topicCategory

4
5

MD_Identification

Attributecitationkeywords
or MD_Keywords
Observation Date Extent information EX_TemporalExtent Classand Time
Spatial represen- MD_GridSpatialRepre
Image Sizetation information sentation
numberOfDimensions

Data type

Explanations

CharacterString

Filename can be title (an attribute of CI_Citation
class). See 19115_No.360
If MD_Sensor class suggested in 19115-2 is notapplied, this will be handled as "title".
High-level geographic data thematic classification to assist in the grouping and search of available geographic data sets. Can be used to group
keywords as well. Listed examples are notexhaustive.
"imageryBaseMapsEarthCover"seems to be themost appropriated among the examples given.
But, "CEOP_Satellite_Imagery" is suggested as abetter term.
Keywords can be used.

TM_Primitive

Date and time for the content of the dataset

CI_CitationClass

Spatio grid dimension
Integer

axisDimensionPropertie Sequence<MD_Dime Row, column, vertical etc. see B.5.14
MD_DimensionNameTypeCode <<CodeList>>snsion>
Resolution of Grid is also represented hereclass
cellGeometry(MD_CellGeometryCo Point or areade)Content information

MD_RangeDimension sequenceIdentifier

6

Data Type

Content information

MD_Band

7

Data Unit

Content information

MD_CoverageDescrip attributeDescription
tionMemberName

cellValueType

Figure 1. CEOP Satellite Metadata Standard (AMSR-E, instrument) first 13 of 21 total fields

record type (see.
19103)

Number of spectral/frequency bands
e.g. £≤byte Integer
Proposed in 19115-2: mandatory (if applicable)
bit representation of data value in raster cell
Unit of physical measurement
Def. Record type (see. 19103): "A Record isused as an implementation representation forfeatures, by keeping a list of (name, value) pairs
in a dictionary. This represents a generic storage
structure for features."3

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CEOP Newsletter No.7

Summary of CEOP Issues Presented at the Joint Meeting of the WCRP Working Group on
Numerical Experimentation (WGNE) and the GEWEX Modeling and Prediction Panel (GMPP)
at Exeter, UK from 11-15 October 2004.
Michael G. Bosilovich, Global Modeling and Assimilation Office, NASA/GSFC, MD, USA

Dr. Michael G. Bosilovich, Co-Chair for the CEOP Modeling Working
Group, represented CEOP at the WGNE/GMPP joint meeting and reported on the status of the CEOP data collection process, current scientificactivities, connections to other international observational and research
efforts and future plans.
The Working Group on Numerical Experimentation (WGNE) was jointly established by the Joint Scientific Committee (JSC) on the WCRP and
the WMO Commission for Atmospheric Sciences (CAS) while the
GEWEX Modeling and Prediction Panel (GMPP) was established by the
GEWEX Scientific Steering Group and endorsed by the JSC. The functions of these groups that make their work synergistic with CEOP
include their joint responsibility in WCRP/GEWEX of fostering the development of atmospheric circulation models for use in weather prediction
and climate studies on all time scales and diagnosing shortcomings
and for promoting coordinated numerical experimentation for validating
model results, observed atmospheric properties, exploring the naturaland forced variability and predictability of the atmosphere.
The participants were informed that many modeling groups are utilizing CEOP data in research and development activities. Specific examples of CEOP analyses were presented including a study being under-

taken by the Global Land Data Assimilation Systems, Land Information
Systems (GLDAS/LIS) Group at the Goddard Space Flight Center(GSFC). Results were shown of testing of 1km spatial resolution offline
land models, using 1km vegetation and leaf area index (LAI) from theNASA Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument, compared to 25km resolution, over CEOP sites thatshow that better representation of the vegetation nearer a site,
improves the land model results. It was also noted that as participantsin the model output component of CEOP, several major Numerical
Weather Prediction and Data Assimilation Centers are validating theirgrid space surface energy fluxes with CEOP reference site data. The
Global Modeling and Assimilation Office (GMAO) at GSFC is also using
the CEOP reference site data as independent validation for testing
remotely sensed skin surface temperature assimilation impact on theenergy and water fluxes. In addition, presentations from Yoshiaki
Takeuchi (JMA) and Sean Miller (UKMO) demonstrated their respective
offices use of CEOP data for internal validation studies. The Groups
were advised that the key attribute of the existing CEOP data set for
Model applications, which includes data from sites that is accessible
from other databases, is that the CEOP data has undergone additional
quality control measures (including visual inspection of all data), andthe format of the data is uniform across all providers.

Proposed CEOP Model Inter-Comparison Experiment Framework
Michael G. Bosilovich, Global Modeling and Assimilation Office, NASA/GSFC, MD, USA

The data collection and science efforts defined in the CEOP
implementation plan (Phase I) encouraged the contribution of many
analysis centers (operational and research) data products. This
would effectively coordinate many different data assimilation products with in-situ and remotely sensed observations. How then can
we exploit the synergy afforded by CEOP for the improvement ofmodels and data assimilation? In November 2004, the National
Aeronautics and Space Administration (NASA) accepted proposals to
the Model, Analysis and Prediction program. This note describes our
response to that program. Here, we summarize the framework of initial experiments to alert the broader international community of thisactivity and to solicit additional comment and participation in theprocess.

relate to the diurnal cycle and seasonal progression (e.g. monsoons).
Previous studies with 2 or 3 analysis systems have shown that,
despite the analysis of observations, the analysis output, especiallyoutput related to the models’ physical processes, can differ greatly
from each other. There will be an inter-comparison of many available
centers’ analyses, including NASA’s next generation systems, to be
used for operational analyses in support of NASA research instrument teams and also for satellite era retrospective-analysis. Theinter-comparison of so many different analyses should reveal theuncertainty of current data assimilation systems, and will contributeto the improvement of operational and retrospective analyses (andalso contribute toward improved climate, seasonal and weather predictions, and the representation of climate variability in reanalysis).

The proposed project will specifically focus on the ability of current global data assimilation systems, individually and in ensemble,
to reproduce all of the components of the water and energy cycles(precipitation, evaporation, transports, water and energy content,
and radiation). The team expects to take advantage of many new
EOS platforms to provide independent global data for cross comparison of the analysis systems. Processes will be investigated that

The main data period that will be the focus of this effort consistsof CEOP’s two annual cycles (EOP3 and EOP4, October 1, 2002 –December 31, 2004). The large number of centers involved showthat there has been a recognition that this timeframe will provide asuperior time period to conduct model and analysis research anddevelopment owing to the richness of the CEOP data collection(including both in-situ and remotely sensed observations, and many

CEOP Newsletter No.7

other data analysis products). The proposed activity will take advantage of the extensive CEOP collection in order to better understandand quantify the uncertainty of analyses. This proposed analysis
inter-comparison project will also implement tools developed by the
Program for Climate Model Diagnosis and Inter-comparison (PCMDI)
for analysis of multiple general circulation models. The Climate andForecasting data standard will also be applied across the different
analyses. This is the accepted standard for the next International
Panel on Climate Change (IPCC) model experiments, so this standard should facilitate collaboration among scientific researchgroups.
The data and diagnostics developed in this project will provide abenchmark for future developments models and analysis systems,
as well as a resource for the international scientific community. A
central scientific priority of CEOP focuses on the measurement,
understanding and modeling of the water and energy cycles in the
Earth system and the relationships of monsoon systems. In particular, the Water and Energy Simulation and Prediction (WESP) working
group is concerned with understanding the gaps in measurements
and the deficiencies of models, and ultimately to define and improve
the skill in predicting hydro-climatological water and energy budgets. The NASA Land Information System (LIS) will contribute fineresolution offline land data for comparison and analysis of the systems. Therefore, this initial project brings focus to three main CEOP
science objectives (water and energy cycles, land atmosphere interactions and monsoon connections) while addressing the principal
needs of the NASA Modeling, Analysis and Prediction (MAP) program.
Another way this proposal connects to CEOP is through issues
that relate to monsoon life cycles. Model inter-comparison studies
have shown simulations of monsoon climate variability by state-ofthe-art models lack fundamental characteristics (e.g. the diurnal
cycle), and that uncertainties in model predictions ultimately can betraced back to inadequate model performance in simulation of theclimatology. The implementation of this activity will follow the CEOP
Inter-monsoon Modeling Study (CIMS) strategy to document the variations of the diurnal and seasonal cycles around the world, using thedata developed in the proposal and with CEOP data.

An important synergistic aspect of this project and CEOP is that
the EOS research satellites are producing critical data for validation
and assimilation, especially the water and energy budgets and CEOP
has agreements to obtain such data. Each parameter is in a different
state of maturity. For example, many MODIS (Moderate-resolution
Imaging Spectroradiometer) data products are only recently becoming more accessible. It has been partly through the endorsement of
CEOP by the Committee on Earth Observation Satellite (CEOS) thatspace agencies have agreed to make such data and products available for use within a fully integrated CEOP database system.
The first objective of the project will be direct inter-comparisonsof key water and energy cycle parameters. The contributing centers
are providing Model Output Location Time Series (MOLTS). These arehigh temporal resolution point output for the nearest CEOP referencesite locations. The small size of these subsets of data, with hightemporal resolution (1-3 hours), facilitates investigation of the diurnal and seasonal cycles (without a great concern about modifying
gridded data). However, we will quickly move to intercomparing the
key water and energy cycle data on a common spatial grid structure.
This will facilitate a quantitative analysis of the uncertainty of all
analyses, as well as the development of an ensemble of analyses. A
first attempt will be simply a linear ensemble of the available data.
This should be a reasonable starting point, as the analyses are alllinked through similar observing systems, and differences will occur
due to the analysis methodology and the model physics. Eventually,
more advanced methods will also be examined, for example, aweighting scheme based on independent observations (such as
TRMM rain rate).
The PCMDI utilities are linked to DODS and Live Access serversthat allow dissemination of data and diagnostics. The data on theserver will include the available centers CEOP data subsetted to key
parameters, ensemble of the analyses, and available EOS data. It isenvisioned that this will ultimately be a resource for the international
CEOP participants and the community in general.
The research team consists of M. Bosilovich (NASA), J. Roads(SIO), C. Peters-Lidard (NASA), and W. K.-M. Lau (NASA), with P.
Glecker (PCMDI) and S. Benedict (CEOP/GEWEX) collaborating. For
more details, contact Michael.Bosilovich@nasa.gov.

Inter-comparisons of seasonal changes between East Asian and South American monsoons:
Preliminary results from the CEOP Inter-Monsoon Studies (CIMS)
Jun Matsumoto and Hiroaki Takahara, Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan

1. Introduction
Traditionally, monsoon climate is thought to exist only in the
Asian-Australian-Indian Ocean-African sector based on the seasonal
wind reversal phenomena, and the South American Continent has
been regarded as‘monsoonless’(Ramage, 1971). However, somerecent studies indicate that the South American Continent is also

monsoonal (e.g., Zhou and Lau, 1997, Chen, 2004).
On the other hand, the East Asian monsoon has been recognized
as a monsoon system, although the main components include theBaiu/Mei-yu frontal zone (BFZ) of mid-latitude origin, which distinguishes it from the South Asian tropical monsoon system (e.g. Taoand Chen, 1987, Ninomiya and Murakami, 1987). In South America,

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CEOP Newsletter No.7

the cloud band called the South Atlantic Convergence Zone (SACZ)
has an influence on its rainy conditions of the monsoon (Kodama,
1992). Here, based on a paper presented at the CEOP InterMonsoon Studies (CIMS) Workshop held at Montevideo, Uruguay(See Page 2), the authors attempt to depict a comparative view ofthe seasonal changes between East Asian and South American
monsoons.
2. Data
The data utilized in the present study are; wind, temperature andspecific humidity data at 850hPa based on NCEP/NCAR reanalysis(Kalnay et al., 1996) and precipitation data derived from CMAP (Xieand Arkin, 1997) for the 22-year period from 1979 to 2000. To
reveal the minute seasonal transitions, pentad mean data are utilized.
3. The monsoon circulation
Figure 1 depicts the distribution of seasonal differences of 850
hPa wind and precipitation between winter and summer in both
Asian and South American regions. In East Asian sector (Fig. 1a),two separate regions are identified in the Mei-yu/Baiu frontal band
(MBFZ) in the central China-Japan area and in the ITCZ cloud bandover the western North Pacific as distinct seasonal rainfall contrast.
For circulation fields, the former is accompanied with pronounced
weakening of northwesterly in summer, while, the latter withstrengthened southwesterly wind. Over the Asian continent, cyclonic
circulation feature surrounding the Tibetan Plateau is clearly seen.
Over South America (Fig. 1b), continental-scale precipitation
changes are also recognized between the equator and 25ºS withenhanced westerly wind between 5ºS and 25ºS, which may be identified as low level monsoonal circulation. The latter circulation will be
related to the development of surface heat low over the continent
locally known as Chaco Low, and the eastward retreat of the subtropical high on the South Atlantic. However, the large difference
between these two monsoons is contrasted by theexistence/absence of a strong winter monsoon from the continent inEast Asia/South America.
4. Seasonal changes of wind and precipitation
Figure 2 depicts the time-latitude sections of 850hPa wind andprecipitation along 110-120ºE and 50-60ºW as a representative
longitude of the continental part of the East Asian and SouthAmerican monsoons, respectively. Over East Asia (Fig. 2a), two precipitation maxima are located at 0-20ºN and 20-35ºN, corresponding to the ITCZ and frontal band. An abrupt onset of westerly wind at
Pentad 28 (late May) accompanied by a sudden increase of precipitation over the South China Sea is a conspicuous feature of summer
monsoon onset. After that, two precipitation belts seem to comeclose together and then the northern band suddenly shifts northward
at Pentad 32 (mid-June) accompanied by the onset of Mei-yu season in the Yangze valley. Southwesterly flow along the MBFZ also
migrates northward to 40ºN at pentad 42 (late July). At Pentad 45(mid- August), a sudden change from westerly to easterly windoccurs in the 20-30ºN zone. After that the MBFZ precipitation gradually decreases.
Over South America (Fig. 2b), two precipitation zones are also
basically recognizable at 0-20ºS and 25-35ºS. The former band
migrates southward as the season progresses from winter to summer, while the latter is rather stable in location and a somewhat
northward shift can be found at about Pentad 65 (late November).
Rainfall amount in the former region tends to be more abundant
after Pentad 70 (mid December). In the wind field, albeit not as distinct either temporally or spatially, a wind shift from easterly to westerly also occurs rather abruptly at about Pentad 66. This maybe
regarded as the summer monsoon onset over South America in the
low-level circulation.
5. Temperature and moisture conditions
Temperature and moisture conditions are also analyzed. In East
Asia, the MBFZ is characterized by the weak temperature and strong
moisture gradient along the frontal zone (Ninomiya, 1984) and thedecrease of temperature gradient occurs in mid-May in an abrupt
manner (Kato, 1985). In Fig. 3a, such features are also recognized.
Over South America (Fig. 3b), of course, the temperature is higher insummer, but the seasonal change amplitude is much smaller thanthat over East Asia. However, if we look at the conditions near therain-belt at 30ºS, the north-south temperature gradient is also
weakened in summer, similar to the situation over East Asia.
Moisture fields over East Asia (Fig. 3a) also exhibit conspicuous
seasonal changes. The increase in moisture content in summer andthe northward intrusion of the moist region after Pentad 35 (lateJune) and up to Pentad 50 (early September) are one of the prominent features. Over South America (Fig. 3b), although wet air invades
also into the southern region in summer, its extent is limited to northof 30ºS and the moisture amount itself is much smaller.
6. Conclusions
In this study, comparisons of seasonal changes between East
Asian and South American monsoons are attempted using the wind,temperature and moisture fields as basic information that will be utilized in future CIMS studies. Although, both monsoon systems exhibit more or less seasonal contrasts between winter and summer,
more vigorous changes are, in general, observed in East Asian monsoon. However, also found is the abrupt wind shift at the onset ofSouth American monsoon in late November. Further studies using
CEOP data are needed for the more comprehensive comparisons of
the two monsoon systems.
References
Chen, T.C., 2004: Maintenance of summer monsoon circulations: A
planetary-scale perspective. J. Climate, 16, 2022-2037.
Kalnay, E. et al., 1996: The NCEP/NCAR 40-year reanalysis project.
BAMS, 77, 437-471
Kato, K., 1985: On the abrupt change in the structure of Baiu front
over the China continent in late May of 1979. JMSJ, 63, 20-35..
Kodama, Y., 1992: Large-scale common features of subtropical pre-

CEOP Newsletter No.7

cipitation zones (the Baiu frontal zone, the SPCZ, and the SACZ).
Part I: JMSJ, 70, 813-835.
Ninomiya, K., 1984: Characteristics of Baiu front as a predominant
subtropical front in the summer northern hemisphere. JMSJ, 62,
880-894.
Ninomiya, K. and T. Murakami, 1987: The early summer rainy season (Baiu) over Japan. Monsoon Meteorology, Eds. C.P. Chang
and T.N. Krishnamurti, Oxford Univ. Press, 93-121.
Ramage, C.S., 1971: Monsoon Meteorology, Academic Press,
296pp.
Tao, S.Y. and L.X. Chen, 1987: A review of recent research of theEast Asian summer monsoon in China. Monsoon Meteorology,
Eds. C.P. Chang and T.N. Krishnamurti, Oxford Univ. Press, 6092.
Xie, P. and P.A. Arkin, 1997: Global precipitation: A 17-year monthly
analysis based on gauge observations, satellite estimates, andnumerical model outputs. BAMS, 78, 2539-2558.
Zhou, J. and K.M. Lau, 1997: Does a monsoon climate exist overSouth America? J. Climate, 11, 1020-1040.

Figure 2 Time-latitude sections of precipitation and 850hPa wind along (a)110-120ºE and (b) 50-60ºW. Thick solid line indicates 0m/s contour line of
850hPa zonal wind.

Figure 1 Spatial distribution of seasonal differences of precipitation and
850hPa wind between summer and winter around (a) East Asia and (b) SouthAmerica. Solid bars at the top and bottom of each figure indicate the meridionalzones in Figures 2 and 3.

Figure 3 Same as Figure 2, but for 850hPa temperature (T) and specifichumidity (q). Warm-color lines are T for 260 (red), 252, 244, 236, and 228(yellow) K. Cold-color lines are q for 10 (deep blue), 8, 6, 4, and 2 (light green)
g/kg.

7

8

CEOP Newsletter No.7

Contribution of the CATCH* project to the CEOP and
Its relations with the AMMA** international project over West Africa*Couplage de l’Atmosphère Tropicale et du Cycle Hydrologique ** African Monsoon Multidisciplinary Analysis

Thierry Lebel and Christian Depraetere, CATCH Project, Grenoble, France

The CATCH observing system is one element of the French component of the AMMA project. CATCH focuses on the long term monitoring of
the water cycle and vegetation dynamics on three mesoscale sites spanning the West African eco-climatic gradient. It operates thanks to thefinancial support given by the French Ministry of Research and by the
French Institute for Development (IRD).
One mesoscale site (the area containing the Niamey, Niger, sahelian
bioclimate) has been in operation since 1990; the second site (upper
Ouémé valley, Benin, soudanian bioclimate) started in 1999; the third site
is located in the Malian Gourma (Mali, sub-desertic bioclimate). National
operational services(meteorology and hydrology) are associated with the
project.
These mesoscale CATCH sites (MS1, MS2 and MS3) play a pivotal
role within the overall AMMA experimental setting (figure 1).
Hydrometeorological monitoring is a key priority for these sites, which will
be operational until the end of the AMMA/LOP in 2010.

Hydrometeorological data of the Ouémé reference site for the years
2001-2003 (figure 2) were transmitted to the CEOP data centre as acontribution to ongoing studies on monsoon inter comparison all over theworld.
Following the building phase initiated in 2002, the AMMA/EOP will
start in 2005 and last till 2007 (figure 3).

Figure 2 List of CATCH sites and rain gauges network on the Upper Ouémé bassin (MS2)

Figure 3 Phases of the AMMA international project

Figure 1 The CATCH meso scale sites referenced as
MS1, MS2 and MS3 as part of AMMA sites

Schedule of CEOP
2001
The CEOP Preliminary Data Period

2002
1 JulyThe CEOP Buildup phase

2003

2004

30 September
1 October

30 September
1 October

The First CEOP Annual Cycle Period

30 September
1 October

The Second CEOP Annual Cycle Period

31 December

Newsletter Editorial Board: Robert SCHIFFER, Carlos R. MECHOSO, Paul D. TRY
Contact Address of International Coordination Body:
Sam BENEDICT (International Coordinator)
742 “H” Avenue
Coronado, CA, 92118, USA
Phone: +1-619-437-7904
Fax: +1-619-437-6814
E-mail: sam.benedict@gewex.org

Dawen YANG (Secretary General), Akiko GODA, Katsunori TAMAGAWA
Department of Civil Engineering, University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Phone: +81-3-5841-6132
Fax: +81-3-5841-6130
E-mail: ceop@monsoon.t.u-tokyo.ac.jp

Supported by: Japan Aerospace Exploration Agency (JAXA), Japan Science and Technology Agency (JST)