影响华北地区的黄河气旋过程分析

利用每小时数值云图、ＴＢＢ资料，常规天气图资料和数值产品资料，分析了１９９４年６月２４－２６日黄河气旋过程，讨论了环境场条件，不同尺度云团的相互作用对气旋生成的影响，给出了中尺度云团的发展演变以及与强降雨的关系，揭示了气旋降雨的中尺度特征，概括了气旋发生发展的综合模型，对气旋的短期预报有一定的参考价值。     

Particle size truncation effect on the inference of effective particle diameter

The effective ice crystal particle diameter (De) of cirrus clouds can be inferred by comparing the measured radar / lidar backscattering ratio with the theoretically calculated one. The calculated ratios are based upon assump-tions of ice crystal particle density and size distribution, and it will be affected by the artificially assumed particle size ranges. This size truncation effect on the inference of effective particle diameter will be investigated theoretically by assuming the cirrus ice particle spherical and particle density of 0.9g / cm3. Results show that the truncation at large particle end has very small effect on the inference of De , but the truncation at the small particle end will have some ef-fect on the inference of De.     

The Impact of Non-Lambertian Wavelength-Dependent Reflecting Surfaces on Stratospheric Radiation and Photochemistry

We have developed models of physically-based cloud and ocean surfacesfor use in photochemical models. These surface models are described in termsof a flux albedo and a normalized reflection function.Through these, the dependence of albedo on wavelength, solar zenithangle, cloud optical depth (cloud surfaces) and surface windspeed (ocean surfaces) are allowed for. In addition, the non-Lambertian nature of these surfaces is accounted for.We have integrated these surfacemodels into a multiple scattering radiative transfer model to assess their effects on the stratospheric radiation field and J-values. This was accomplished by comparison with results obtainedusing Lambertian, constant albedo surfaces. Comparisons of stratospheric radiation fields revealed that boththe wavelength and directional dependences of the cloud and oceansurfaces could be large effects.Differences between calculated J-values varied from 0 to 12% depending upon species, solar zenith angle, andheight.The J-values were then used as input for a chemical box model to examine the effects these surfaces had on stratospheric chemistry. Comparisons were made against box model runs using J-values fromconstant surfaces. Overall, the effect was on the order of 10%.Differences in number densities using these different surfacesvaried with latitude, height and species.Runs were made with and without heterogeneous chemistry.     

Research Advance of Shrub Dendrochronology in the Cold and Arid Regions of China

Along with the booming of dendrochronology in China, the woody species for the tree-ring study have expanded gradually from tree species to the shrub and dwarf shrub species in the last decades. The zonal woody species in the vast alpine mountains, arid desert areas and arid regions in China are mostly shrubs and semi-shrubs, which is very important to understand the process of regional evolution, environmental protection and ecological recovery. In this paper, the shrub species which have been studied on tree rings in cold and arid areas of China were collected and sorted, and the fundamental research advances were presented, which include the shrub tree ring identification, radial growth characteristics, and chronology construction by different parameters. The applications of shrub dendrochronology to the subjects in eco-response, paleoclimate reconstruction, hydrological process, ecological study of artificial forest and ecological restoration were also presented. The prospect of shrub dendrochronology in the future was also discussed.     

The Global Atmospheric Electrical Circuit and Climate

Evidence is emerging for physical links among clouds, global temperatures, the global atmospheric electrical circuit and cosmic ray ionisation. The global circuit extends throughout the atmosphere from the planetary surface to the lower layers of the ionosphere. Cosmic rays are the principal source of atmospheric ions away from the continental boundary layer: the ions formed permit a vertical conduction current to flow in the fair weather part of the global circuit. Through the (inverse) solar modulation of cosmic rays, the resulting columnar ionisation changes may allow the global circuit to convey a solar influence to meteorological phenomena of the lower atmosphere. Electrical effects on non-thunderstorm clouds have been proposed to occur via the ion-assisted formation of ultra-fine aerosol, which can grow to sizes able to act as cloud condensation nuclei, or through the increased ice nucleation capability of charged aerosols. Even small atmospheric electrical modulations on the aerosol size distribution can affect cloud properties and modify the radiative balance of the atmosphere, through changes communicated globally by the atmospheric electrical circuit. Despite a long history of work in related areas of geophysics, the direct and inverse relationships between the global circuit and global climate remain largely quantitatively unexplored. From reviewing atmospheric electrical measurements made over two centuries and possible paleoclimate proxies, global atmospheric electrical circuit variability should be expected on many timescales.     

云室中两种检测冰晶方法的比较

通过实验比较了在云室中检测冰晶的两种方法－糖盘法和玻片法，结果表明玻璃片测到的冰晶数比糖盘高数倍，讨论了两种方法检测的上下限，优缺点及应用范围。     

"99.6"梅雨锋暴雨云和降水物理过程的中尺度数值模拟

用MM5(V2)中尺度非静力数值模式对长江中下游地区的梅雨锋降水的云和降水进行模拟研究。对于可分辨尺度的降水，采用Reisner霸显式方案；对云内微物理过程特别是对各种水成物的源汇项进行了详细分析，以期深入了解梅雨锋云系内部的云物理过程。     

盛夏强降水的多普勒雷达回波特征的初步分析

使用红外云图、多普勒雷达回波的强度场、速度场及VAD产品，对2002年7月24日夜间至25日凌晨的中天山及其北部地区的强降水天气过程进行了分析、诊断，得出对降水过程不同时段临近预报有指导意义的结论和指标。     

雹云判别和适宜作业时机分析

人工防雹作业中关键是雹云判别和适时作业。雹云判别用4因子组合表征雹云特征，还能判别雹落区；在cb云路径上确定查强区进行雹云判别，以决定适时作业的时间。     

适用于寒旱区十要素无人自动气象站的研制

采用DT500数据采集器作为中心控制系统，研制成具有风向、风速、空气温度、空气湿度、地温、气压、日照、蒸发、辐射和降雨量等10个参数全自动采集的气象站系统。该系统适用于高寒、高湿、强风沙无人区等恶劣环境下正常工作。