Abstract:Several principal ozone modeling approaches are reviewed and a semi-empirical approach called the Integrated Empirical Rate (IER) model is applied as the ozone calculation scheme in CAPPS. The result of a test using data set observed in Beijing city shows that the scheme is practicable.

Abstract:The analysis using Gama type raindrop distribution show that the effect of downdrafts W on the relation between the radar reflectivity factor Z and the precipitation rate I should not be neglected when its dimension reaches or exceeds 5×10¹cm·s^-1.In the form Z=AI^b,the coefficient A decreases and the exponent b increases as W increases,which is in agreement with the results from two cases computations well.The influence of the ambient pressure field p,which actually reflects the role of air density,is also analysed and the results indicates that A decreases and the exponent b increases as p decreases.In addition,some results of the discussion on the micro-physics characteristics of the raindrop spectra observed in two cases are presented.

Abstract:The impact of large-scale circulation conditions from June to October in 2000 on the tropic cyclone activities is analyzed. In 2000 tropic cyclone activities were less than climatic average, the intrinsic reason leading to this lopsided state is the anomaly of large-scale circulation, and it is the anomaly that impacted reducing the number of tropic storm outset and landing in nonactivity phase of tropic cyclone, even debasing the total number of tropic storm in this year. This general circulation anomaly is most obvious in the June and October.

Abstract:General circulation features over the Northern Hemisphere in 2001 are analyzed. It's shown that the subtropical high at 500hPa over the western Pacific in the winter of 2000/2001 and the spring of 2001 was stronger than normal, and was weaker in the summer and the autumn. In the summer of 2001, the 500hPa geopotential height anomaly was positive in the Eurasia, and the positive center was over Lake Baikal. Both in the winter and the summer, the East Asian monsoon was weaker than normal. In the July of 2001, the equatorial convergence zone was more active than normal, and its position was more north than normal. The SSTa in the eastern tropical Pacific was negative in 2001. The results show that the anomalies of both the sea temperature the tropical Pacific and atmosphere circulation would exert a significant impact on the weather and climate in China.

Abstract:Global climate has been warming persistently. The year 2001 has become the second warmest year on record since 1860. During the winter 2000, extreme cold and heavy snow weather was experienced in most Asia and the United States. Persistent severe drought events occurred over East Asia, South Asia, West Asia and Central Asia in the first half year of 2001 and serious floods occurred in South Asia, Southeast Asia during the summer monsoon season. Severe floods occurred in Europe, Africa and South America. Activities of the North Atlantic hurricanes were very busy during June through November and typhoons caused serious disaster.

Abstract:The chief climate characteristics in 2001 are showed as follows: in most areas, the annual precipitation was less than or near the normal. Droughts appeared in varying degrees in the seasons, especially the spring through summer drought in the northern part of China, and the summer drought in the middle and lower reaches of the Changjiang River, and the autumn drought in the eastern part of China. The droughts heavily influenced the agricultural production. In the flood season, no heavy rainfall and floods happened in extensive regions. In fall, continuous rain appeared in the eastern part of Southwest China evidently. Annual mean temperature was higher than normal in most areas,the unusual severe winter appeared in Northeast China, and the scorching days appeared continuously in most areas in summer. The typhoons landed more than normal,the windy and dusty weather appeared earlier and frequent, the severe snow disaster occurred in Xingjiang and Inner Monglia provinces, strong convectional weather such as hails and tornadoes occurred near the normal.

Abstract:By calculation of the equivalent received power of testing signal input power at the radar antenna feed, the radar reflectivity Z(dBz) value of testing signal input power can be calculated by the meteorological radar equation.By comparing with the displayed Z value of the testing signal input power after the calibration of the radar received power on the radar normally observation model,it is examined whether the error of the calibration of the weather radar received power meet the technical demands.

Abstract:A technique to determine the remote sounding capacity of a secondary wind finding radar is introduced. First, a sounding meteorogragh is launched at another place, and the leading data are obtained by GPS and transit. Then, to capture the tracks of the sounding meteorogragh, the check of remote sounding capacity of the secondary wind finding radar system can be completed.

Abstract:By using the charts of lightening positioner and radar-711, the position of a thunderstorm can be decided. It is a very good method to judge the location of a thunderstorm, and to conduct exactly and timely hail suppression by antiaircraft guns.

Abstract:The surface synoptic situations which affect the air pollution in Beijing area are classified. Using the data of surface observation and upper air sounding from 1998 to 2000 in the southern suburbs of Beijing, the meteorological features of the surface and lower layer in Beijing area that is controlled by the various surface synoptic situations are analyzed. It is found that air pollutants are easily confluent and accumulated when the weather in Beijing is controlled by the low-pressure type at surface. Comparing the influences of the various surface synoptic situations on sulfur dioxide, nitrogen dioxide, PM₁₀, carbon monoxide, respectively, it is shown that the influence of the same surface synoptic situation on various air pollutants is different,It further approves that the low-pressure weather would easily cause the severe pollution in Beijing.

Abstract:Xiangtoushan Nature Reserve locates in the southern subtropical wet monsoon climate zone.The general climatic characteristics are rich heat,abundant rainfall,high air humidity,long wet season and short dry season,long plant-growth period,wind directions changed with seasons and noticeable vertical change of climate,etc.Nature disasters such as strong wind,typhoon and thunderstorm occur sometimes.

Abstract:According to the date of temperature and precipitation in the Tarim irrigation area from January,1961 to December 1999,the climate of the Tarim irrigation area is analysed.The results show that the precipitation of the Tarim irrigation area for 40 years appears to be ascending (4.569mm/10 a),the precipitation in autumn appears to be descending (-3 451mm/10 a) and the mean annual temperature appears to be going up (0.065℃/10 a), especially in the later 1990′s.The warming trend in winter is more than the cooling trend in summer.For this reason, in terms of the limit of the end of 1970′s the climate of the Tarim irrigation area for 40 years might be divided into two stages,the former is a cold period,and the latter is a warm period.