Dynamical downscaling of General Circulation Model (GCM) data for any region has been made possible due to a set of physics options and model dynamics within the Weather Research and Forecasting (WRF) model. This study evaluated the performance of an ensemble of physics options in simulating rainfall during wet and dry seasons of Lao PDR. The model evaluation criteria focused on identifying the optimum physics options for a range of scenarios. No single combination of physics options performed well in all scenarios reflecting the importance of using different parameterizations according to the geographic location and the intended application of the results. For the dry season, none of the ensemble members performed satisfactorily for the southern region of Lao PDR, while all the ensemble members performed well for the northern and central regions. While almost all the WRF simulations overestimated the rainfall during the wet season, BMJ for cumulus physics performed better in the northern and central regions, and KF performed better in the south region. The YSU scheme performed best as the planetary boundary layer for both wet and dry seasons, while WSM5 for the wet season and Lin for the dry season gave the best model performance as the microphysics option.

中文翻译：

---

评估WRF物理组合在模拟旱季和旱季期间老挝人民民主共和国的降雨方面的性能

由于天气研究和预报（WRF）模型中的一组物理选项和模型动力学，可以实现任何区域的通用环流模型（GCM）数据的动态缩减。这项研究评估了一组物理方案在模拟老挝人民民主共和国的干湿季降雨过程中的性能。模型评估标准着重于确定各种场景的最佳物理选择。没有一个物理选项的组合在所有情况下都能很好地反映出根据地理位置和结果的预期用途使用不同的参数化的重要性。在旱季，老挝人民民主共和国南部地区没有一个合奏团表现令人满意，而北部和中部地区的合奏团表现都不错。虽然几乎所有的WRF模拟都高估了雨季的降雨量，但BMJ的积云物理方法在北部和中部地区表现更好，而KF在南部地区表现更好。YSU方案在干湿两季均作为行星边界层表现最佳，而湿季的WSM5和干季的Lin则作为微观物理学选项提供了最佳的模型性能。