The Effection Of Dry Intrusion And The Relation With The Heat Of Condensation In The Rainstorm And The Duststorm

Based on T213 and other observational datasets, a severe heavy rain occurred in Changjiang-Huaihe basins during 4-5 July 2003 and a duststorm occurred in the north of middle of the Inner Mongolia during 27-28 Mar 2004 are studied simply. The mesoscale numerical model MM5 (V3) is used to simulate the two processes. Using the model output with high spatial and temporal resolution, we study the characteristic and mechanism of the two processes in more detail. The results show that dry intrusion not only consists but also plays an important role in the development of the two processes. Affected by both subtropical high and dry intrusion in the rainfall process, potential equivalent temperature above the Jianghui area forms saddle-backed shape,which avails the amassment of the instability energy under the middle of the troposphere and the release of the instability energy above the middle of the troposphere.Affected by the dry intrusion getting stronger,the saddele-backed shape is to be perpendicular,which procreates strong ascent motion.In the duststorm process the dry intrusion descends from near tropopause-level.Far from the cyclone the dry intrusion undercuts rearward-ascending warm air to give an ana-cold front,and near from the cyclone it overruns the warm air to give an kata-cold frontThe heat of condensation and the dry intrusion make temperature increase and decrease respectively.The chang of the temperature field changes the height field,and the change of the height field changes the wind field, and in the result which makes the dry intrusion and the cyclone becoming stronger.