This arcticle dealswith the data from 108 meteorological stations and the ErlangMountain ice station in the southwest China.Based on the climate statistical p rincip les and methods, we find 13 stations which climatic characteristics are similar to ErlangMountain, and the analysis focuses on themeteorological factors over the EmeiMountain and Kangding station in order to reconstructwire ice - covering series in the ErlangMountain. The mathematical model of the relationship between the meteorological factors of Kangding station and wire ice - covering series in ErlangMountain is established based on the op timal subset regression method. Through the fitting equation, the inter - annual ice - cover sequence in the Erlang Mountain is estimated from the year 1951 to 2001, and combined with the sequence of ErlangMountain’sice - cover in winter from 2001 to 2008,we confirm the reconstructed sequence is coincident with climate trend under the background of globalwarming.

The annual variation of temperature and precipitation ofurban and rural stationswas analyzed for a 48-year period through the climate observation data collected from 11 weather stations in the Beijing region from the period of1961-2008. The results showed that the urban heat island (UHI) was increasing, and annual temperature ofurban and rural stations in the Beijing area obviously increased. The average temperature in urban stations is increasing faster than that in rural stations. The climate variations trends in Beijing during the recent48 years and the data showing Beijing’s development indicates that the rapid development ofBeijing aswell as urbanization has greatly influenced the local climate change in Beijing.
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A model simulation of“99. 6”Meiyu Front rainstorm by nonhydrostatic mesoscale modelMM5V3 is analyzed in an effort to study the mechanism of theMeiyu front. The results of trajectories analysis show that four airstreams converge into the low vortex. On low levels, the southwest Jet and the northeast flow increased convergence on low levels as the low meso -α vortexwith shear line develop ing, and the westly Jet and the eastly Jet increased divergence on high levels. It is this collocation from low levels to high levels that urged meso -α low vortex to develop. The diagnosis of convective momentum transport (CMT) shows that, the budget residual X of the horizontalmomentum has different effects in different periods of the low vortex with the shear line: On low levels, X strengthened the southwest flow to north on the occurring stage, on middle levels, X accelerated northwest flow behind EastAsia Trough to north and also accelerated northwest flow ahead of EastAsia Trough to the south.All these were in favor of deepening the EastAsia Trough and mingling cold and warm air, and gave favorable conditions to p roduce rainstorm. On the develop ing period, X has the reverse direction with southwest flow, which p revented southwest flow to the north. At the same time, it decelerated the cold (warm) flow behind ( ahead of) the East Asia Trough. on the level of 500 hPa. The diagnosis of CMT on the violently develop ing period of the mesoscale system shows that strong X always related to the meso -β systemswhich brought intense ascendingmotions.While the shear line launched out, X has strong decelerating effects for southwest flow. The result of diagnosis also revealed that large - scale environment field has overt energy interconversion with subgrid scale systems on the intense develop ing period of the mesoscale system, and energy p rimarilywas transported to microscale systems. Furthermore, energy exchanges on high levels were closely with the location of Upper Jet. The diagnoses of apparent heat source indicate that releasing of strong latent heat of condensation concomitant with intense develop ing of the low vortex. Onlymeso -β systemsA and B have better relation with apparent heat source. The characters of apparentmoist sink are analogous to that of apparent heat source.