A Regional Climate Model for the Indian Monsoon

这个项目的目的是调查印度季风行为的各个方面。首席研究员将开发一个区域模型，该模型适用于测试有关控制季风开始的机制、季风在印度次大陆上向北传播、季风中断期和季风消退的假设。为此，首席研究员已经成功地将国家气象中心（NMC）的eta模式与全球环流模式联系起来，以模拟季风行为。eta模式主要用于短期预报和模拟一些物理过程，包括边界层的物理、日循环、辐射与云的相互作用和对流。表面物理模块，目前是一个简单的板能量和桶水文模型，将被最先进的生物圈模型所取代。这个生物圈模型应该能更真实地描述由土壤湿度和植被控制的水文循环。一旦实现，耦合模型的模拟表面通量将与观测值进行比较。然后，耦合模式将用于模拟5月初至9月底的季风。为了评估该模式模拟季风时空变化的能力，将把产生的时间平均场和瞬态特征与观测结果进行比较。最后，将用耦合模型对季风行为的各种假设进行检验。＊＊＊

9502817 Vernekar The objective of this project is to investigate various aspects of the behavior of the Indian monsoon. The principal investigator will develop a regional model which is appropriate for testing hypotheses concerning mechanisms governing the onset of the monsoon, the northward propagation of the onset over the Indian subcontinent, monsoon break periods, and monsoon withdrawal. Towards this end, the principal investigator already has successfully linked the National Meteorological Center's (NMC) eta model to the global general circulation model to simulate monsoon behavior. The eta model is used primarily for short-range predictions and simulates a number of physical processes including the physics of the boundary layer, the diurnal cycle, radiation interactions with clouds, and convection. The surface physics module, currently a simple slab energy and bucket hydrology model, will be replaced with a state-of-the-art biosphere model. This biosphere model should provide more realistic representations of the hydrologic cycle as governed by soil moisture and vegetation. Once implemented, the coupled model's simulated surface fluxes will be compared with observations. The coupled model will then be used to simulate the monsoon from the beginning of May to the end of September. To assess the ability of the model to simulate the space-time variability of the monsoon, the time- averaged fields as well as the transient characteristics produced will be compared with those from observation. Finally, the various hypotheses of monsoon behavior will be tested with the coupled model. ***