David M Lawrence and Julia M Slingo

Two of the primary goals of the PROMISE program are to assess the natural variability and predictability of monsoons on seasonal and interannual timescales and to assess the potential for benefits from seasonal predictions for hydrology and agricultural management. To this end, the role of interactive vegetation and soil moisture dynamics in simulations of the worlds' major monsoons is assessed in the Unified Model (UM). Particular attention is paid to the model's representation of the seasonal evolution of the monsoons including the monsoon onset, active/break cycles of precipitation, and diurnal variability. The UM is run in high resolution (~0.8 degree) climatological SST mode with vegetation and soil moisture evolving according to the Met Office Surface Exchange Scheme (MOSES 2) and the Top-down Representation of Interactive Foliage and Flora Including Dynamics (TRIFFID) schemes. This run is compared to a run in which the seasonal evolution of vegetation parameters such as leaf area index (LAI) are specified according to satellite data from the ISLSCP and MODIS projects. The satellite data reflects, in particular, the extensive agricultural land use in the monsoon regions which emphasizes the importance of human intervention in the seasonal evolution of vegetation in these regions.

Figure 1 (18 Kb)

Figure 2 (34 Kb)

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