ENVK2-CT1999-00022: Predictability and Variability of Monsoons and the Agricultural and Hydrological Impacts of Climate Change (PROMISE)

 

Month 6 Report

 

The project has progressed satisfactorily and no partners have expressed any difficulties in reaching the milestones as set out in the Workplan. Summarised below are the principle achievements in each workpackage. It is confirmed that the PROMISE Workshop and meeting will be held at ICTP, Trieste during 28 May to 15 June 2001 as part of the Summer Colloquium on 'Land-Atmosphere Interactions and the Hydrological Cycle'. Prof. Slingo will be a Co-Director of the Summer Colloquium.

 

COORDINATION

 

WP4000: Development of the PROMISE Data Archive

 

A subcontract has been negotiated with CINECA and the PROMISE Data Archive has been established. Rainfall data from the ECMWF Reanalyses and PROVOST  ensembles have been installed and scripts are being developed to enable web-based data processing and visualisation (CINECA, ICTP, UREADMY). Data requirements for the users of climate and seasonal predictions have been agreed with the partners and with the DEMETER group. They are documented on the PROMISE website (UREADMY).

 

WP5000: Collaboration with research institutions in monsoon-affected countries.

 

Links have been established with Agrhymet and CERAAS in Senegal with a view to developing appropriate crop models (CIRAD). Through the ICTP Associate Scientist scheme, three institutions in Brazil, India and the Philippines have been nominated which will allow a number of funded visits. An associate member from the Kenyan Met. Department has already visited ICTP and worked on PROMISE (ICTP). ICRISAT in Hydrabhad, India has been visited and information on relevant crop yields has been acquired and is being used by PROMISE scientists (UREADAG).

 

WP6000: Project coordination

 

The PROMISE website has been established (http://ugamp.nerc.ac.uk/promise) and the Monsoons Online site has been further developed and maintained (http://www.met.reading.ac.uk/cag/MOL). The PROMISE brochure, aimed at non-specialists and users of PROMISE research, has been published and will be distributed widely. A PROMISE poster has been produced.

 

RESEARCH

 

WP1000: Natural variability of monsoon climates.

 

Evidence for intraseasonal variations in the W. African monsoon on 10-60 day timescales has been found in reanalysis and observational data (LMD). While modifications to the convective and boundary layer schemes has led to improvements in the monsoon simulations (The Met. Office), the onset of the W. African monsoon is still too early by 1-2 months (UREADMY) leading to major difficultie in predicting the interannual behaviour. Further, it has been demonstrated that longstanding systematic errors over the Maritime Continent can have a detrimental effect on the mean climate and interannual variability of the Asian Summer Monsoon. Part of the systematic error is associated with a poor representation of the diurnal cycle (UREADMY).

 

WP1100: Seasonal predictability of monsoon climates.

 

Following close consultation with the DEMETER group, a basic archive has been agreed. All further work awaits the DEMETER integrations.

 

WP1200: Sensitivity of monsoon variability/predictability to SST forcing.

 

The effect of Indian Ocean SSTs on E. African rainfall has been investigated. It has been shown that the dipole SST mode in the Indian Ocean can be associated with strong rainfall events (UREADMY). Model sensitivity experiments have shown that Mediterranean SSTs can have a significant impact on Sahelian rainfall (The. Met. Office).Using ensembles of seasonal integrations with the ECMWF model, it has been shown that whilst the dominant mode of interannual variability is chaotic, the second mode shows a significant relationship with ENSO demonstrating that there is potential predictability for the Asian Summer monsoon (ICTP).

 

WP1300: Impact of land surface processes on tropical climate variability

 

Sensitivity experiments have demonstrated the importance of soil moisture in influencing monsoon variability on daily to interannual timescales. Whereas African rainfall increases systematically with increasing soil wetness, the response of the Indian summer monsoon is less clear due to the greater contribution from atmospheric moisture convergence (CNRM). Similarly it has been shown that Sahelian rainfall is controlled by the near surface moist static energy, confirming the importance of soil wetness (UB).

 

WP2000: Climate change scenarios.

 

A control and an IPCC SRES-b2 scenario integration has been completed for the period 1950 to 2070  and data will be supplied to the PROMISE data archive. The control integration has a realistic climate and shows very little climate drift (CNRM). A new version of the LMD Zoom Model with an improved land surface parametrization has been developed and will be used to provide high resolution scenarios of climate change over monsoon regions (LMD). It has been demonstrated that increases in greenhouse gas concentrations intensify the Asian summer monsoon and its variability (MPI).  Changes in the hydrological cycle are being investigated and data on river run-off for the Indus and Ganges/Brahma-putra from the EC project ERACC are being acquired  (DMI).

 

WP2100: Impact of land use changes on future monsoon climates

 

A land use model for the Sahel has been developed which partitions the area into fuel-wood, cropland for subsistence and export, fallow and grazing land and can respond to the demands of the human population under conditions of variable rainfall. A method for converting these land use types into the vegetation classifications used in model surface parametrizations has been developed (NERC).

 

WP3000: Ground hydrology and water resources for monsoon climates

 

Substantial progress has been made in assembling the data required for a hydrological model for W. Africa. Flow direction, river networks, main lakes, reservoirs and wetlands have been identified. Recent data on irrigated areas have been acquired (NERC). A study of methodologies for river routeing has been completed with a view to coupling the climate and hydrological models (LMD).

 

WP3100: Seasonal prediction of crop yields and assessment of climate change impacts on crop productivity.

 

Indian groundnut yields for the period 1966-95 have been acquired for ICRISAT and have been used to perform a detailed study of the relationship between yield and rainfall on a regional basis. A dynamic crop model has been tested at various sites (UREADMY, UREADAG). Following a review of simple crop models adapted to regional applications, the existing water balance crop model, SARRA,  will be developed further. Modules to handle the carbon cycle and crop phenology are being formulated using field data (CIRAD). Preliminary analysis of the climate-vegetation feedbacks operating in climate change has shown that dieback of the Amazon rainforest is associated with a drying of Amazonia in response to a warming of Pacific SSTs.