Impact of land-surface processes on tropical climate variability - WP1300

Partners involved: CNRM (lead contractor), ICTP, MPI, UB

PROMISE aims to investigate the role of land surface processes and of anomalies in land surface conditions in determining the predictability and variability of monsoon climates.

Key achievements so far:

• sensitivity experiments have demonstrated the importance of land-surface processes in influencing monsoon variability on daily to interannual timecales. Global AGCM experiments confirm that realistic oil moisture boundary conditions are necessary for simulating the mid-latitude stationary waves with a significant impact on both extratropical and tropical precipitation

• an analysis of the relationship between Eurasian snow-depth anomalies and indices of the Asian monsoon circulation has been carried out using data from numerical simulations performed in the context ofthe PRISM project

• a selection of multi-linear regressors have been studied to demonstrate their effectiveness in predicting Sahelian June-September rainfall. It was found that April to June meridonal patterns of near surface MSE content control the amplitude and the timing of the Sahelian July-to-September rainy season. Wet Sahelian seasons are usually preceded by stronger than normal MSE gradients during Boreal spring.

• 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

Publications related to this topic by PROMISE partners

Douville H. and J-F. Royer (1996): Sensitivity of the Asian summer monsoon to an anomalous Eurasian snow cover within the METEO-FRANCE GCM, Climate Dynamics, 12, 441-448

Douville H, Chauvin F (2000): Relevance of soil moisture for seasonal climate predictions: a preliminary study. Climate Dynamics 16, 719-736

Douville H, Chauvin F, Broqua H (2001): Influence of soil moisture on the Asian and African monsoons. Part I: Mean monsoon and daily precipitation. J Climate (in press)

Douville H (2001): Influence of soil moisture on the Asian and African monsoons. Part II: interannual variability. J Climate (submitted)

Ferranti, L. and F. Molteni, 1999: Ensemble simulations of Eurasian snow-depth anomalies and their influence on the summer Asian monsoon. Quaterly Journal of the Meteorological Society, 125, 2597-2610

Corti, S., F. Molteni and C. Brankovic, 2000: Predictability of snow-depth anomalies over Eurasia and associated circulation patterns. Quaterly Journal of the Meteorological Society, 126, 241-262

Further information

see:
Work package description in the proposal
Detailed annual report (available to PROMISE partners or with the permission of the lead contractor)
18 month progress reports submitted by the partners for this work package

or:
contact Emily Black (emily@met.reading.ac.uk)