The Orographic Influence on Intense Precipitation at Tianchi
A strong heavy rainfall occurred in Xinjiang Tainchi during 22 ～23 June 2010,accumulated precipitation of 6 hours was up to 124 rm.The above-mentioned case has been analyzed using WRF model.The impacts of Tianshan Mountains on the severe convection are discussed.The results show that the low-level northwest airflows of northern Xinjiang were blocked by the topography of the Bogda,and a portion of the winds at a speed of 12 m · s-1 climbed along the windward slope,another part of the air flow around the west side along the mountain climb,and because of the funneling,west air velocity was up to (18 ～24) m · s-1.The two flows provided dynamic conditions.Because of the terTain blocks and the narrow tube effect,low-levels horizontal airflow velocity decreased with height on the Bogda Mountains of the western slope,causing the hillside to further enhance the level of convergence,relative positive vorticity reached as high as 136 × 10-5 s-1 which was in favour of precipitation.High and low wind field configuration contrary and vertical wind shear strengthened was conducive to strong convection occurs.Multi-cell merge with local convective cells is the main reason of the occurrence of rainstorm.
Heaven Lake of Celestial Mountainssevere convectionnumerical simulationorographic effectconvection cell merge
NETL
NSTL
万方数据
维普
