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

Month 18 Report

The project has progressed satisfactorily and no partners anticipate any difficulties with reaching the year 2 milestones as set out in the work plan.  Summarised below are the principle achievements in each work package. 

COORDINATION

WP4000:  Development of the PROMISE data archive

A prototype of the PROMISE archive has been implemented by CINECA under ICTP supervision.  This can be accessed at http://www.cineca.it/promise.  It includes data from re-analyses, seasonal forecasting projects and climate scenario runs generated by CNRM.  The web-based interface allows data to be selected on the basis of region and time.  The data can either be visualised interactively on the web or downloaded in GRADS format. 

WP5000 Collaboration with research institutions in monsoon-affected countries

A workshop on “Land-atmosphere interactions in climate models” followed by a conference on “Climate variability and land-surface processes:  Physical Interactions and regional impacts” have been held at ICTP with the co-sponsorship of PROMISE.  These activities were attended by over 130 scientists, including about 80 from developing countries some of whom were sponsored by ICTP through the PROMISE  contribution to the meeting.  During the workshop, the overall structure and goals of the PROMISE were presented, and a demonstration was held on the use of the data archive.  The conference doubled as the annual PROMISE and this provided an opportunity for the partners to disseminate PROMISE research to participants from monsoon-affected countries. (ICTP and UREADMY)

WP 6000 Project coordination

The PROMISE website (http://ugamp.nerc.ac.uk/promise) has expanded considerably and underwent a major rewrite in the last six months to accommodate the information contained in the annual report.  Preparation for the end of project meeting has continued.  Preliminary plans have been made for the meeting to take place at ICTP in the spring of 2003.  The head of START/CLIMAG, Peter Gregory, has expressed interest in a joint conference between PROMISE and CLIMAG and a short proposal will be submitted to him for presentation at the next START steering group meeting.  (UREADMY)

RESEARCH

WP1000:  Natural variability of monsoon climates

Improved simulation of the Somali Jet and intensity of West African rainfall distribution were achieved for a 20 year integration using a development version of the global climate model, with better representation of convection (the Met Office).  The vegetation scheme of the Hadley Centre climate model has been upgraded and will be used to examine the effect of vegetation seasonality on the simulation of monsoon climates (the Met Office and UREADMY).  A set of statistical procedures in the PV-wave language has been assembled for the analysis of intraseasonal variability in climate simulations (CNRM).

WP1100:  Seasonal predictability of monsoon climates

Close collaboration with the DEMETER group has continued.  The DEMETER hindcast integrations are closely following the ERA40 initial data availability.  All hindcasts in the period November 1986 – May 1992 have been completed.  Preliminary indications are that dynamical indices of the circulation over the northern Indian Ocean and southern Asia have some hindcast skill.  Examination of a larger time sample will determine statistical significance (ECMWF).

WP 1200:  Sensitivity of monsoon variability/predictability to SST forcing

The sensitivity of African rainfall to SST variability in the Indian and Atlantic Oceans and the Mediterranean Sea has been investigated using both GCM integrations and analysis of model and observational data.  Analysis of observational data shows that Indian Ocean zonal SST gradient is a primary control on East African rainfall.  It was further found that this perturbed gradient was, in some years, associated with ENSO (UREADMY).  A dynamical scenario that explains how higher than usual Mediterranean SSTs can cause excessive rainfall in the Sahel has been developed using data from idealised SST experiments (the Met Office).  New atmospheric GCM experiments confirm that rainfall variability along the Guinea Coast is strongly linked to SST anomalies in the Eastern Tropical Atlantic, while there is no clear link to Sahelian precipitation (MPI) 

WP 1300 Impact of land surface processes on tropical climate variability

Sensitivity experiments demonstrate the importance of land-surface processes in influencing monsoon variability on daily to interannual timescales.  Global AGCM experiments confirm that realistic soil moisture boundary conditions are necessary for simulating the mid-latitude stationary waves with a significant impact on both extratropical and tropical precipitation (CNRM).  Earlier work has shown that Sahelian rainfall is controlled by near surface moist static energy.  The extent to which this is controlled by land surface conditions as opposed to SST is being studied using numerical sensitivity experiments (UB).  The necessity of modelling the dynamic vegetation processes for accurate simulation of interdecadal changes in Sahelian rainfall has been demonstrated using atmospheric GCMs coupled to a simple dynamic vegetation model (MPI).  The latest version of the ECMWF atmospheric GCM is being tested through a set of ensemble simulations with observed SST covering all winter seasons during the 80’s.  These simulations will be used as the control for future experimentation on the sensitivity to land surface conditions over the tropical continents (ICTP).

WP2000:  Climate change scenarios

A transient future climate simulation for the 21^st century using a coupled GCM shows that the increase of low-level moisture convergence over Africa is mainly due to the increased water content in a warmer atmosphere and to a northward displacement of the convergence zone.  The simulated change on the global hydrological cycle has also been analysed.  The model achieves a reasonable simulation of the present-day precipitation climatology.  During the 2070-2100 period, there was found to be stronger convection over the ICTZ, a relative drying in the subtropics and enhanced monsoon precipitation over India and Africa (CNRM).  The effect of greenhouse warming on the Asian subcontinent is also being investigated using the ECHAM4 AGM (DMI)

 WP 2100:  Impact of land use changes on future monsoon climates

The collation of data relating to land use and deforestation over West Africa has been completed Data from the FAP, UNEP, the World Bank, the World Resources Institute and from remotely sensed data from AVHRR (Advanced very high-resolution  radiometer) have also been collected.  This data is being used to complete estimates of past and present land cover in West Africa which will be used as the basis of alternative land use scenarios (NERC). 

WP 3000:  Ground hydrology and water resources for monsoon climates

The water budget and river flows of the most important rivers over India have been simulated using a global land surface model including a river routing scheme.  The integration for the second year (1988) has been completed.  In general, the 1988 flow is in good agreement with observed monthly data (LMD).  Good progress has been made on the development of a detailed hydrological model for West Africa.  Data have been collated for calibration and a new high resolution soil classes data set has been obtained and is being adapted for the West African region, as part of the land-use change application.  (NERC)

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

Two versions of a conceptual crop model have been released in DELPHI programming language:  one for cereals (sorghum and millet) and one for peanuts.  The models accurately simulate crop growth, ground cover and yield under water and radiation limited conditions.  Agrhymet has been sub-contracted to provide Sahel weather data for PROMISE crop simulations and to develop crop modelling software for yield forecasting.  The historical climate database will become available to PROMISE at the end of this reporting period (September 2001).  Extensive experimental datasets for sorghum have been generated in collaboration with ICRISAT in Mali.  This has allowed model calibration and validation for a small set of environments.    A tool for the spatial analysis and representation of PROMISE results has also been developed. (CIRAD).  Good progress has been made on developing a conceptual framework for a new crop model (HAPPY – Huge Area Potential Peanut Yields).  The model is now being tested and calibrated using observed data. (UREADMY and UREADAG)