不同对流参数化方案在登陆浙闽台风降水预报中的比较试验   总被引：3，自引：7，他引：3  

薛根元  张建海  陈红梅  诸晓明 《高原气象》2007,26(4):765-773

利用MM5模式,在MRF和Blackadar两种边界层参数化方案下,分别选用KF2、Grell和BM三种对流参数化方案对登陆浙闽两省的6个台风暴雨过程进行数值模拟,模拟结果的对比分析及其与观测资料的比较表明:KF2方案和Grell方案在降水量较小时误差较小,BM方案在降水量较大时误差较小;对大雨以上量级的降水预报,KF2方案、Grell方案和Blackadar方案组合效果较好,而BM方案则适宜与MRF方案组合;KF2方案不适合时效较长的降水预报。在台风"卡努"的个例试验中,位涡分布特征在积分后期对不同参数化方案十分敏感,这种差异进而影响了降水预报的准确性,同时暴雨中心潜热加热的时间演变总体特征表现为暴雨中心凝结潜热加热随时间积分有明显变化。因此,在预报和模拟中应根据预报和研究对象的特点来选择对流参数化方案。  相似文献   

积云对流参数化方案对大气含水量及降水的影响   总被引：4，自引：2，他引：4  

刘屹岷  刘琨  吴国雄 《大气科学》2007,31(6):1201-1211

中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室所发展的高分辨率全球大气环流谱模式SAMIL, 自从发展成R42L26新版本之后, 显示出对全球气候基本态的模拟能力, 但模式对流层低层以及热带地区整层偏干, 且对热带地区的降水模拟存在“双赤道辐合带”这一普遍误差, 在赤道地区以及北半球中纬度降水偏少, 而在拉丁美洲降水偏多。敏感性试验表明这些误差是相互联系的。通过将700 hPa以下的相对湿度趋近于“观测资料”的试验显示模拟的降水误差减小了。据此, 对Tiedtke 积云对流参数化方案中的浅对流部分进行修改, 增加了浅对流的侧向混合的卷入以及卷出率, 并减小了对流方案中的云水[CD*2]雨水的转换率, 将其耦合到模式中。积分结果表明, 修改后的方案明显改进了湿度和温度场的模拟, 对降水的模拟能力有了很大的提高, 基本消除了“双赤道辐合带”现象。  相似文献   

A Statistically-Based Low-Level Cloud Scheme and Its Tentative Application in a General Circulation Model     

DAI Fushan  YU Rucong  ZHANG Xuehong  YU Yongqiang 《Acta Meteorologica Sinica》2005,19(3):263-274

1. Introduction Clouds are active factors in the climate system, and have significant influences on the global hydrolog- ical and thermal budgets. More and more the climate model developers and researchers have realized the im- portance to appropriately describe the interactions be- tween cloud and radiation in the atmospheric general circulation model (AGCM). It is well known that cloud is one of the contributing factors to the uncertainties in the simulation of climate by AGCM. Especiall…  相似文献   

The Uncertainty of Mesoscale Numerical Prediction of Heavy Rain in South China and the Ensemble Simulations     

陈静  薛纪善  颜宏 《Acta Meteorologica Sinica》2005,19(1):1-18

1. IntroductionHeavy rain is a kind of severe natural calamitythat influences South China. After decades of years oftests and theoretical exploration by Chinese scientists,significant progresses have been achieved in its predic-tion and basic theoretical studies (Huang, 1986; Xue,1999; Zhou et al., 2003). Currently, the mesoscale nu-merical model has already been employed as one of themajor tools in the prediction and research on heavyrain in South China, promoting considerably the ac-curac…  相似文献   

Extensions To A Similarity Hypothesis For Shallow Cumulus Convection     

A. R. Brown  A. L. M. Grant 《Boundary-Layer Meteorology》2000,97(2):173-190

Grant and Brown (Quart. J. Roy. Meteorol. Soc., 125, 1913–1936) proposed a similarity hypothesis for shallow cumulus convection and evaluated it using large-eddy simulation results. Here, results from an additional independent simulation are used to provide further support for the basic theory. At the same time, some extensions to the theory are proposed. It is shown that the effects of non-zero fluxes at cloud base can be conveniently accounted for by a simple representation of the transport of scalar variance into the convecting layer. Theeffects of having more complex mean profile shapes within the layer (and hence changes in the gradient production of variance) are also investigated.  相似文献   

三相云显式降水方案和高原东部"96.1”暴雪成因的中尺度数值模拟   总被引：48，自引：18，他引：30  

邓远平  程麟生  张小玲 《高原气象》2000,19(4):401-414

对“９６．１”高原暴雪天气过程进行的天气学成因分析指出,欧洲阻高崩溃,里海－咸海横槽转竖,槽后向南入侵青藏高原的干冷偏北气流与槽前来自孟加拉湾和中印半岛向北不断推进的强劲西南暖湿气流,在青藏高原东部部交汇而形成,发展并持续的切变线,是产生的高原暴雪的中尺度天气系统。通过将冰相云微物理过程参数化和三相云 降水方案引入ＭＭ４而发展的中尺度模式模拟系统,在采用常规观测资料的条件下,基本上成功地模拟出了“  相似文献   

第五代PSU/NCAR中尺度模式系统(MM5)介绍V:预报模式(MM5模块)     

张华  李耀辉  王劲松 《干旱气象》2000,(4)

文章对MM 5预报模块的结构 ,原理及主要功能作了较为详尽的介绍。为了考察模式对暴雨过程的预报能力 ,以 1996年 8月河北特大暴雨为例进行数值试验。试验结果表明 :MM 5模式可以正确地模拟这次大暴雨的直接影响系统及其环流背景形势的演变和发展 ,其暴雨中心的强度和落区与实际比较接近。  相似文献   

GRAPES中尺度模式中不同积云参数化方案预报性能对比研究   总被引：3，自引：2，他引：1  

郭云云  邓莲堂  范广洲  李泽椿 《气象》2015,41(8):932-941

利用我国新一代中尺度数值模式GRAPES_Meso,采用KFeta和BMJ两种积云对流参数化方案,对我国2009年冬季(1月)和夏季(6—8月)天气进行批量回报试验。回报试验结果表明：在冬季,两种方案对GRAPES_Meso模式的预报性能影响差异较小。在夏季,两种方案对模式回报效果的影响表现明显。在低层BMJ方案对形势场的回报性能略优于KFeta方案,中层则是KFeta方案明显优于BMJ方案,而在高层KFeta方案略优于BMJ方案。TS评分检验表明KFeta方案对降水的预报总体上优于BMJ方案,特别是中雨到暴雨量级在华南地区KFeta方案有明显的优势。两个方案预报积云降水平均贡献率的空间分布差异主要表现在低纬度洋面上,BMJ方案的贡献率比KFeta方案大。两个方案积云降水贡献率的概率分布形态在小雨量级上都呈陡峭的“U”型分布。KFeta方案随着降水量级的增大逐渐向大贡献率偏移,特大暴雨量级时基本上是积云降水的贡献;而BMJ参数化方案则是随着降水量级的增大逐渐向小贡献率偏移,特大暴雨量级时基本上是格点降水的贡献。  相似文献   

Performance of Convective Parameterization Schemes in Asia Using RegCM:Simulations in Three Typical Regions for the Period 1998–2002     

Shaukat ALI  DAN Li  FU Congbin  YANG Yang 《大气科学进展》2015,32(5):715-730

This study discusses the sensitivity of convective parameterization schemes(CPSs) in the Regional Climate Model(version 4.3)(Reg CM4.3) over East/South Asia. The simulations using different CPSs in Reg CM are compared to discover a suitable scheme for this region, as the performance of different schemes is greatly influenced by region and seasonality. Over Southeast China and the Bay of Bengal, the Grell scheme exhibits the lowest RMSEs of summer precipitation compared to observed data. Moreover, the Emanuel over land and Grell over ocean(ELGO) scheme enhances the simulation, in comparison with any single CPS(Grell/Emanuel) over Western Ghats, Sri Lanka, and Southeast India. Over the Huang–Huai–Hai Plain(3H) and Tibetan Plateau(TP) regions of China, the Tiedtke scheme simulates the more reasonable summer precipitation with high correlation coefficient and comparable amplitude. Especially, it reproduces a minimum convective precipitation bias of 8 mm d-1and the lowest RMSEs throughout the year over East/South Asia. Furthermore, for seasonal variation of precipitation, the Tiedtke scheme results are closer to the observed data over the 3H and TP regions. However, none of the CPSs is able to simulate the seasonal variation over North Pakistan(NP). In comparison with previous research, the results of this study support the Grell scheme over South Asia. However, the Tiedtke scheme shows superiority for the 3H, TP and NP regions. The thicker PBL, less surface latent heat flux, the unique ability of deep convection and the entrainment process in the Tiedtke scheme are responsible for reducing the wet bias.  相似文献   

Aerosol-Cloud-Precipitation Interactions in WRF Model: Sensitivity to Autoconversion Parameterization          下载免费PDF全文

XIE Xiaoning  LIU Xiaodong 《Acta Meteorologica Sinica》2015,29(1):72-81

Cloud-to-rain autoconversion process is an important player in aerosol loading, cloud morphology, and precipitation variations because it can modulate cloud microphysical characteristics depending on the participation of aerosols, and affects the spatio-temporal distribution and total amount of precipitation. By applying the Kessler, the Khairoutdinov-Kogan(KK), and the Dispersion autoconversion parameterization schemes in a set of sensitivity experiments, the indirect effects of aerosols on clouds and precipitation are investigated for a deep convective cloud system in Beijing under various aerosol concentration backgrounds from 50 to 10000 cm-3. Numerical experiments show that aerosol-induced precipitation change is strongly dependent on autoconversion parameterization schemes. For the Kessler scheme, the average cumulative precipitation is enhanced slightly with increasing aerosols, whereas surface precipitation is reduced significantly with increasing aerosols for the KK scheme. Moreover, precipitation varies non-monotonically for the Dispersion scheme, increasing with aerosols at lower concentrations and decreasing at higher concentrations.These different trends of aerosol-induced precipitation change are mainly ascribed to differences in rain water content under these three autoconversion parameterization schemes. Therefore, this study suggests that accurate parameterization of cloud microphysical processes, particularly the cloud-to-rain autoconversion process, is needed for improving the scientific understanding of aerosol-cloud-precipitation interactions.  相似文献