【作者】 王洪利；

【导师】 沈桐立； 马镜娴；

【作者基本信息】 南京气象学院 ， 气象学， 2004， 硕士

【摘要】 利用国家气象中心GRAPeS三维变分同化系统实现了AMSU—A／B微波遥感资料的直接同化，结合中尺度模式MM5，以个例方式研究了其在我国夏季暴雨数值预报中的作用。以2003年7月4日“南京暴雨”作为研究对象，结果如下：1)同化试验结果表明，AMSU-A资料的主要作用在于调节温度场，温度正增量伴随湿度的负增量，反之亦然；AMSU-B资料主要贡献在于改进湿度场，湿度正增量伴随温度的负增量，反之亦然。2)预报结果表明，同化AMSU-A／B资料后的初始场可以改善模拟的暴雨落区及强度，结果与实况更加接近。仅用AMSU-A资料同化后的初始场可改善暴雨的模拟强度，而仅用AMSU-B资料的同化改进了暴雨的落区的模拟。3)用伴随敏感性分析方法确定了影响南京暴雨前6小时预报的敏感性区域，它们位于对流层低层雨区的西侧及西南方向，改善大气低层要素的观测和分析质量能够进一步提高预报水平。4)伴随同化预报试验表明：经MM5V1-4Dvar系统同化后形成的初值对降水的预报及其它要素场的预报有一定的改善。个例结果说明，AMSU资料在我国夏季暴雨数值预报中有着一定的潜在应用前景。更多还原

【Abstract】 AMSU data is assimilated into the mesoscale model MM5 based on GRAPeS-3D-Var system, and its impact on rainfall numerical modeling is studied by experiments also. Conclusions drawn from the practice of a heavy rainfall process during 04-05, July, 2003 are: 1) results from the assimilation tests show that AMSU-A data contributes mainly to adjusting temperature, positive temperature increment companies with negative humidity increment, and verso also; AMSU-B data contributes mainly to adjusting humidity, positive humidity increment companies with negative temperature increment, and verso also. 2) Results from forecasts experiments show that both the rainfall location and intensity modeled are improved when AMSU-A/B data assimilated to initial condition fields. AMSU-A data has a positive effect on the intensity of rainfall modeling, and AMSU-B data improves the modeling of the location of rainfall. 3) This paper identifies the sensitivity location and variables of 6h forecast errors by the method of adjiont sensitivity analysis also, and they locate west and south west of the real rainfall field. The forecast skill may be improved if low-level observation data is of high quality. 4) The experiments of 4D-Var and forecasts show that, the forecast skill of rain and other model variables are improved when the retrieval fields of AMSU are assimilated into the initial condition by MM5 4D-Var system. The experiments in this paper show that AMSU data may have great latency in rainfall forecasts in summer in our country.更多还原