In-Situ Measurements of Cloud-Precipitation Microphysics in the East Asian Monsoon Region Since 1960          下载免费PDF全文

WANG Donghai  YIN Jinfang  ZHAI Guoqing 《Acta Meteorologica Sinica》2015,29(2):155-179

A large number of in-situ measurements of cloud-precipitation microphysical properties have been made since 1960, including measurements of particle size distribution, particle concentration, and liquid water content of clouds and rain. These measurements have contributed to considerable progress in understanding microphysical processes in clouds and precipitation and significant improvements in parameterizations of cloud microphysics in numerical models. This work reviews key findings regarding cloud-precipitation microphysics over China. The total number concentrations of various particles vary significantly, with certain characteristic spatial scales. The size distributions of cloud droplets in stratiform clouds can generally be fit with gamma distributions, but the fit parameters cover a wide range. Raindrop size distributions(RSDs)associated with stratiform clouds can be fit with either exponential or gamma distributions, while RSDs associated with convective or mixed stratiform-cumuliform clouds are best fit with gamma distributions.Concentrations of ice nuclei(IN) over China are higher than those observed over other regions, and increase exponentially as temperature decreases. The particle size distributions of ice crystals, snow crystals, and hailstones sampled at a variety of locations can be reliably approximated by using exponential distributions,while aerosol particle size distributions are best described as the sum of a modified gamma distribution and a Junge power-law distribution. These results are helpful for evaluating and improving the fidelity of physical processes and hydrometeor fields simulated by microphysical parameterizations. The comprehensive summary and analysis of previous work presented here also provide useful guidelines for the design of future observational programs.  相似文献   

An Attempt to Improve Kessler-Type Parameterization of Warm Cloud Microphysical Conversion Processes Using CloudSat Observations   总被引：1，自引：1，他引：0       下载免费PDF全文

YIN Jinfang  WANG Donghai  ZHAI Guoqing 《Acta Meteorologica Sinica》2015,29(1):82-92

Improvements to the Kessler-type parameterization of warm cloud microphysical conversion processes (also called autoconversion) are proposed based on a large number of CloudSat observations between Jun...  相似文献   

A preliminary study of the variation of phytoplankton absorption coefficients in the northern South China Sea     

WUJingyu  HONGHuasheng  SHANGShaoling  DAIMinhan  LEEZhongping  LIShaojing 《海洋学报(英文版)》2009,28(5):17-29

The temporal and spatial variabilities of phytoplankton absorption coefficients (a ph (λ)) and their relationships with physical processes in the northern South China Sea were examined, based on in situ data collected from two cruise surveys during May 14 to 25, 2001 and November 2 to 21, 2002. Significant changes in the surface water in a ph values and B/R ratios (a ph (440)/a ph (675)) were observed in May, which were caused by a phytoplankton bloom on the inner shelf stimulated by a large river plume due...  相似文献   

北太平洋涡旋对基于细尺度参数化的海洋内部混合的影响     

陈娟  李少峰  曹安州  宋金宝 《海洋与湖沼》2020,51(2):248-257

基于Vector Geometry方法对2016—2018年的高度计资料进行涡旋识别,并使用细尺度参数化方法和Argo数据计算了涡旋附近的海洋内部扩散率,分析了北太平洋的涡旋对海洋内部混合的影响。结果显示,研究区域在涡旋影响下的平均扩散率比无涡旋影响下的值大6%,并且气旋涡增强了600—1200m深度的混合,对600—900m深度的混合影响最大,可达18%;反气旋涡明显增强了300—900m深度的混合,但对900—1200m深度的混合没有明显影响。随着与涡旋中心距离的增大,涡旋外围混合扩散率缓慢减小,涡旋内部混合扩散率变化不明显,此结果与2014年3—10月在24°—36°N、132°—152°E区域的一个个例分析结果一致。此外,随着涡旋强度的增大,海洋内部混合明显增强。统计结果表明,在研究区域, 90%的扩散率值在10~(-5.5)—10~(-4)m~2/s范围内。  相似文献   

双矩阵算法的L波段多角度玉米微波辐射参数化模型     

张谦  柴琳娜  施建成 《遥感学报》2017,21(2):182-192

双矩阵MD(Matrix-Doubling)算法是辐射传输方程的一种数值解,考虑了植被层内的多次散射信号,具有较高的模拟精度。但受限于算法的复杂性,很难直接应用到地表参数的反演中。本文以玉米覆盖地表为研究对象,基于MD算法的模拟数据,发展了一种L波段多角度微波辐射参数化模型。基于模拟数据的对比结果表明,参数化模型具有与理论模型相当的精度,两者之间的发射率误差不超过0.004(V极化)和0.007(H极化)。同时,结合黑河流域的地面实测数据,利用本论文中发展的参数化模型模拟了纯玉米像元的辐射亮温。该模拟结果与相同像元尺度上机载L波段微波辐射计(PLMR)观测亮温之间的差异基本在10 K以内。  相似文献   

中国2003年北极海冰调查及未来北极海冰研究战略   总被引：5，自引：1，他引：4       下载免费PDF全文

李志军  张占海 《极地研究》2004,16(3):202-210

以建立气候模式中的海冰模式为主线 ,首先回顾了国际上海冰模式发展现状和趋势 ,从现有模式机理上存在的问题说明认识海冰各物理过程的现场和实验室调查研究的关键科学问题。之后介绍了中国第二次北极科学考察中的海冰调查内容。最后结合国内调查研究能力和国际上海冰科学发展走向 ,根据国内外资料和极地海冰的客观现象 ,提出 6项战略 ,希望作为以后中国北极海冰理论和模式为背景的现场和实验室研究的方向。  相似文献   

基于改进Noah LSM和数值天气预报耦合模式对表层土壤湿度在典型暴雨过程中的模拟          下载免费PDF全文

ZHENG Zi-Yan  ZHANG Wan-Chang  XU Jing-Wen  YAN Zhong-Wei  LU Xue-Mei 《大气和海洋科学快报》2011,4(1):18-23

Surface soil moisture has great impact on both meso- and microscale atmospheric processes, especially on severe local convection processes and on the dynamics of short-lived torrential rains. To promote the performance of the land surface model (LSM) in surface soil moisture simulations, a hybrid hydrologic runoff parameterization scheme based upon the essential modeling theories of the Xin’anjiang model and TOPography based hydrological MODEL (TOPMODEL) was developed in preference to the simple water balance model (SWB) in the Noah LSM. Using a strategy for coupling and integrating this modified Noah LSM to the Global/Regional Assimilation and Prediction System (GRAPES) analogous to that used with the standard Noah LSM, a simulation of atmosphere-land surface interactions for a torrential event during 2007 in Shandong was attempted. The results suggested that the surface, 10-cm depth soil moisture simulated by GRAPES using the modified hydrologic approach agrees well with the observations. Improvements from the simulated results were found, especially over eastern Shandong. The simulated results, compared with the products of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) soil moisture datasets, indicated a consistent spatial pattern over all of China. The temporal variation of surface soil moisture was validated with the data at an observation station, also demonstrated that GRAPES with modified Noah LSM exhibits a more reasonable response to precipitation events, even though biases and systematic trends may still exist.  相似文献   

大洋细结构混合参数化方法在世界大洋环流模式中的应用     

刘又毓  范植松 《中国海洋大学学报(自然科学版)》2005,35(4):534-538

在大洋环流模式中,铅直混合的参数化方法起着关键性的作用。将大洋细结构混合参数化方法首次应用于世界大洋环流模式中。使用中科院大气所(LASG)发展的20层世界大洋环流模式(OGCM)ML20,月平均风场作为强迫场,利用ML20模式在稳定初始状态下运行300a后的计算结果作为本实验进行数值模拟的初始场。该参数化方法对世界大洋环流模式的影响主要表现为：永久性温度跃层的厚度明显变薄;对深层水和底层水的模拟有改进;对南极中层水的模拟比较成功;但是对赤道海区的模拟结果欠佳。  相似文献   

2016年夏季北冰洋浮冰站近地层辐射和湍流通量观测     

沈辉  杨清华  孙启振  孙晓宇  赵杰臣  张林 《海洋学报》2019,41(3):12-22

2016年8月7－14日中国第七次北极科学考察期间,在83°N附近设立的长期浮冰站开展了辐射和湍流通量观测研究。结果表明,观测期间反照率变化范围为0.64~0.92,平均反照率为0.78;基于现场观测数据评估了PW79、HIRHAM、ARCSYM和CCSM3 4种不同复杂度的反照率参数化方案在天气尺度的表现,最为复杂的CCSM3结果优于其他参数化方案,但不能体现降雪条件下的反照率快速增长。浮冰区冰雪面平均净辐射为18.10 W/m2,平均感热通量为1.73 W/m2,平均潜热通量为5.55 W/m2,海冰表面消融率为（0.30±0.22） cm/d,表明此时北冰洋浮冰正处于快速消融期。冰面的平均动量通量为0.098（kg·m/s）/（m2·s）,动量通量与风速有很好的对应关系,相关系数达0.80。  相似文献   

耦合模式中海浪参数对台风浪预报的影响研究     

丁维炜  齐琳琳  赵文斌  刘潮  赵金波  孙苗芯 《海洋预报》2019,36(1):37-51

以西北太平洋一次"双台风"共同影响下的台风浪为例,针对模式中风摄入和白帽耗散、底摩擦、波破碎、波-波非线性相互作用等海浪物理过程对台风浪预报的影响进行了敏感性试验分析。在此基础上,基于各物理过程最优参数化方案探讨了耦合模式和单独海浪模式的海浪预报性能,分析了耦合模式的海浪预报场分布特征。结果表明:不同海浪物理过程参数化对于波高预报的准确性是有所差异的。在相对最优的海浪各参数化方案组合下,无论耦合模式还是单独海浪模式都能较好地反映波高的变化和分布趋势。相比而言,耦合模式对于台风浪大值区的浪高预报要比单独海浪模式的更接近观测,且可以很好地刻画出双台风影响下浪的分布演变特征,对于西太平洋台风浪的预报具有很好的适用性。  相似文献