黄河上游降水云层对流特性及降水微结构机制研究

主要利用1997—2000年6～9月在黄河上游河曲地区实施人工增水实验所获取的各类降水云层回波、雨滴谱及多点宏观气象资料，进一步阐明各类云层降水中对流作用的普遍性和特殊性，并且通过全过程的雨滴谱的演变个例，初步揭示了该地区云中降水微物理过程可能存在冷云和暖云两种机制且暖云机制起重要作用。以上是该地区产生降水频繁的重要原因。     

用蒙特卡洛方法求取云层的反射率与和透过率

本文利用蒙特卡罗方法计算了平面云层的反射率与透射率，给出了不同光学厚度，不同入射角下云层反射率与透射率随天底角的分布，以及吸收作用对反射与透射的影响。     

通过个例分析看人工增雨的效果

通过个例分析看人工增雨的效果潘进军（内蒙古气象科研所）１９９０年７月３－５日，一次蒙古冷槽过程影响我区中东部地区。从连续几天的天气图上看出，北部有一东移发展的蒙古冷槽，向我区大部分地区输送冷空气。与此同时，低槽前下方有一小高压向东北缓慢移动。这样，一...     

怎样理解降自蔽光高层云下的霰

20 0 4年 3月 1 7日 1 7时 2 3分至 1 7时 37分 ,我站降形似圆锥形且着地反跳的颗粒状固态降水 ,骤降骤止 ,强度变化也很大。按规定应记阵性霰 ,报“87”才对 ,但在观天判云时发现上空为蔽光高层云。根据降水性质与降水云层的联系判断 ,有两种不同的见解 :一是确实记霰 ,但由于上层为蔽光高层云 ,其降水性质应按非阵性处理 ,按“77”编报 ;二是认为应记阵性霰 ,报“87”才对。霰的出现标志云中对流强 ,大气不稳定 ,降水期间肯定有对流云存在。两种见解各有道理 ,但笔者认为上述第二种记法较适宜。理由是 ,尽管上层有蔽光高层云 ,但所降之物…     

吉林省层状云中过冷水含量分布特征及人工增雨潜力研究

2001～2002年在实施人工增雨作业的同时利用美国粒子测量系统 ,对吉林省 5～7月降水性层状云进行了科研探测。通过对探测资料的分析 ,得到以下结论 :(1 )吉林省的降水性层状云主要分为 3种云型 :雨层云降水、蔽光高层云—层积云降水、透光高层云降水。其中雨层云中过冷水含量最大 ;(2 )云中过冷水含量与云底高度为负相关 ,与过冷层厚度为正相关 ;(3) 3种云型中距 0℃层高度以上 400～600m高度范围内过冷水含量达最大 ;(4) 3种云型的可播度为 86 %。雨层云的人工增雨潜力为最大。     

Applications of AMSR-E Measurements for Tropical Cyclone Predictions Part Ⅰ： Retrieval of Sea Surface Temperature and Wind Speed

Existing satellite microwave algorithms for retrieving Sea Surface Temperature （SST） and Wind （SSW） are applicable primarily for non-raining cloudy conditions. With the launch of the Earth Observing System （EOS） Aqua satellite in 2002, the Advanced Microwave Scanning Radiometer （AMSRoE） onboard provides some unique measurements at lower frequencies which are sensitive to ocean surface parameters under adverse weather conditions. In this study, a new algorithm is developed to derive SST and SSW for hurricane predictions such as hurricane vortex analysis from the AMSRoE measurements at 6.925 and 10.65 GHz. In the algorithm, the effects of precipitation emission and scattering on the measurements are properly taken into account. The algorithm performances are evaluated with buoy measurements and aircraft dropsonde data. It is found that the root mean square （RMS） errors for SST and SSW are about 1.8 K and 1.9 m s^- 1, respectively, when the results are compared with the buoy data over open oceans under precipitating clouds （e.g., its liquid water path is larger than 0.5 mm）, while they are 1.1 K for SST and 2.0 m s^-1 for SSW, respectively, when the retrievals are validated against the dropsonde measurements over warm oceans. These results indicate that our newly developed algorithm can provide some critical surface information for tropical cycle predictions. Currently, this newly developed algorithm has been implemented into the hybrid variational scheme for the hurricane vortex analysis to provide predictions of SST and SSW fields.     

A review of cloud-resolving model studies of convective processes

Convective processes affect large-scale environments through cloud-radiation interaction, cloud micro- physical processes, and surface rainfall processes. Over the last three decades, cloud-resolving models （CRMs） have demonstrated to be capable of simulating convective-radiative responses to an imposed large-scale forcing. The CRM-produced cloud and radiative properties have been utilized to study the convective- related processes and their ensemble effects on large-scale circulations. This review the recent progress on the understanding of convective processes with the use of CRM simulations, including precipitation processes; cloud microphysical and radiative processes; dynamical processes; precipitation efficiency; diurnal variations of tropical oceanic convection; local-scale atmosphere-ocean coupling processes; and tropical convective-radiative equilibrium states. Two different ongoing applications of CRMs to general circulation models （GCMs） are discussed： replacing convection and cloud schemes for studying the interaction between cloud systems and large-scale circulation, and improving the schemes for climate simulations.     

吉林省春季降水性层状云基本结构及降水潜力的初步研究

2001年、2002年利用美国粒子测量系统（PMS）对吉林省5～7月降水性层状云在实施人工增雨作业的同时进行了科研探测,取得了一批资料,对这些资料进行计算后得到以下结论： （1）吉林省春季降水性层状云宏观结构主要分为三种云型即：Ns、As op-Sc op、Astra。 （2）不同云型其云中过冷水含量、云滴数密度不同,其中Ns云型的云中过冷水含量、云滴数密度最大,分别达到0．2737g／m^3、205．3个／L,其次是Asop-Sc op云层,其过冷水含量、云滴数密度分别为0．1693g／m^3、117．5个／L,过冷水含量、云滴数密度最小的云层结构为Astra,分别为0.1054 g／m^3、98．6个／L。 （3）云中过冷水含量与云底高度为负相关,与过冷层厚度为正相关. （4）三种云型的云中过冷水含量、云滴数密度距0℃层高度的分布基本一致：在距0℃层高度以上400-600m高度范围内过冷水含量、云滴数密度达最大,之后随着距0℃层高度的增加云中过冷水含量、云滴数密度迅速减小。 （5）吉林省春季降水性层状云的可播度为86％;三种云型的人工降水潜力有所不同,即：Ns云型潜力最大,达41．3％,其次是As op-Sc op云型潜力为28．4％,潜力最小的云型为As tra,为26．6％。