基于TRMM PR和VIRS探测的西北太平洋台风云参数和降水特征

发布时间：2018-04-19 12:05

本文选题：TRMM + PR　；参考：《中国科学技术大学》2016年博士论文

【摘要】：西北太平洋(Northwest Pacific,简称NWP)是全球台风(Tropical Cyclone,简称TC)的频发海域,该区域的台风云参数和降水研究,有助于我们充分认识台风生成、演变和消散特征以及气候反馈效应,同时为模式中台风成云致雨过程的模拟提供观测依据,进而提高台风路径和强度预报能力。本论文利用热带测雨卫星TRMM上搭载的测雨雷达(PR)和可见/红外扫描仪(VIRS)的探测资料和TMPA 3B42 (TRMM Multi-satellite Precipitation Analysis 3B42)资料,结合JAXA(日本空间发展署)、CMA(国家气象局)提供的热带气旋资料,研究了西北太平洋台风云系云参数特征和台风降水贡献(TC precipitaiton contribution,简称TCPC)特征,并对比分析了台风降水和非台风降水在降水强度、降水频次、垂直结构、深对流和穿透性对流活动等方面的差异。1 台风降水云和非降水云云参数特征通过PR与VIRS的融合资料和反演的云参数,对西北太平洋台风系统中降水云(precipitaiting clouds,简称PC)和非降水云(non-precipitaiting clouds,简称NPC)云参数特征进行分析,结果表明：1)台风系统内降水云和非降水云的云滴有效粒子半径(effective radius,简称Re)的差异小,而PC的光学厚度(cloud optical thickness,简称COT)明显高于NPC,前者多变化于40～140之间,后者多小于40：PC的云水路径(Cloud water path,简称CWP)明显高于NPC,120g/m2可以认为是两者之间的阈值。2)地表降水概率与云参数之间关系的分析表明,降水概率随着光学厚度和云水路径的增加而逐渐增大：而随着云滴有效粒子半径的增加,降水概率先增大后减小。当云系的云水路径小于1000 g/m2时,降水概率随着云水路径的增加而增大,与云滴有效粒子半径的大小无关：当云水路径超过1000g/m2时,降水概率则是云滴有效粒子半径和云水路径的函数。总体上,大云滴粒子半径和大云水路径更容易产生降水。3)云参数阈值识别降水的分析结果表明,光学厚度大于40、云水路径高于120 g/ms且光学厚度大于40、10.8微米通道亮温低于260K且光学厚度高于50,这三个指标对降水的识别效果好,TS评分分别为0.48,0.48和0.50。该阈值识别方法同样适用于MODIS云产品,为我们利用卫星观测识别降水提供了新的途径。2 台风和非台风降水及光谱特征通过对JAXA/EORC热带台风数据集资料的分析,实现了台风区和非台风区的分离,并结合对PR和VIRS的融合观测资料的分析,结果揭示了1998-2007年东亚雨季台风及非台风降水的气候特征和降水云红外信号特征：1)东亚台风降水强度谱较非台风降水谱更宽,特别是台风中对流降水强度谱分布可5-20mm/h之间。2)东亚地区降水的主要形式是非台风层云降水,频次可达60%以上；台风层云和对流降水频次较小,最大仅能达20%和5%。3)台风和非台风降水的垂直结构在冻结层之下(～4 km)差异明显,台风对流降水云随着云顶亮温减小,冻结层之下降水率随高度减小而迅速增大,非台风对流降水则几乎保持不变。4)台风降水云较非台风降水云的云顶亮温更低,两者的概率密度峰值差异可达15K。3 台风降水贡献特征结合CMA提供的台风最佳路径数据集资料,通过对逐3小时,0.250分辨率的TMPA 3B42降水数据产品分析,研究了西北太平洋地区台风降水贡献的季节变化、月变化以及年变化特征。结果表明：1)整个台风季(5月～12月),台风降水贡献从洋面向内陆递减,150N-250N之间的洋面可达40%,而内陆地区仅为4%。此外,强台风对总降水的贡献较弱台风更大。2)在月尺度上,逐月的台风降水对局地总降水的贡献最大可达60%，其中8月份台风降水对整个西太洋总降水的贡献达到峰值(28%),而台风降水对陆面总降水的贡献则在12月达到峰值(23%)。3)在年尺度上,台风降水对整个西太洋面总降水的贡献于2004年达到峰值(～30%)；对陆面总降水的贡献则在1998年达到峰值(～20%)。4)E1Nino年和La Nina年台风降水贡献差异较大,El Nino年台风降水贡献较中性年增长了约6%,而La Nina年则较中性年减少了6%。4 台风和非台风系统的深对流和穿透性对流通过对1998～2011年6月至9月PR降水廓线资料的分析,研究了西北太平洋地区台风系统和非台风系统中深对流和穿透性对流活动的差异,并分析了台风活动占西北太平洋地区总的深对流和穿透性对流活动的比例。结果表明：1)西北太平洋台风中深对流和穿透性对流活动主要发生在洋面,以15°N-25°N之间洋面出现频次最高：而非台风中深对流和穿透性对流活动则在陆面出现频繁。2)台风中深对流和穿透性对流降水频次较低,分别为0.01%～0.15%之间和0.005%～0.02%之间：而非台风中深对流和穿透性对流降水频次较高,分别可达0.15%和0.02%以上。3)台风中深对流和穿透性对流降水强度大,在西北太平洋的大部分地区降水强度分别超过14 mm/h和22 mm/h,且空间分布不均。非台风中深对流(穿透性对流)降水强度较小,主要分布在10 mm/h～14 mm/h(10 mm/h ～18 mm/h).4)西北太平洋上发生的深对流事件中2%～30%由台风系统贡献,穿透性对流事件中台风活动所占比例明显增加,比例可达到50%以上。
[Abstract]:The Northwest Pacific (NWP) is the frequent sea area of the global Tropical Cyclone (TC). The study of the typhoon parameters and precipitation in this area will help us to fully understand the formation, evolution and dissipation of typhoon and the effect of climate feedback, and provide the observation for the simulation of typhoon cloud induced rain in the model. According to this, the typhoon track and intensity prediction ability is improved. This paper uses the detection data of the rain measurement radar (PR) and the visible / infrared scanner (VIRS) on the tropical rain satellite TRMM and the TMPA 3B42 (TRMM Multi-satellite Precipitation Analysis 3B42) data, combined with the heat provided by JAXA (the Japan Space Development Agency) and the CMA (National Meteorological Administration). With cyclonic data, the characteristics of cloud parameters and typhoon precipitation contribution (TC precipitaiton contribution, TCPC) in the Northwest Pacific platform are studied, and the differences of typhoon precipitation and non typhoon precipitation in precipitation intensity, precipitation frequency, vertical structure, deep convection and penetrating convective activity are compared and analyzed in.1 typhoon precipitation clouds. The parameters of the non precipitation cloud and cloud parameters are analyzed by the fusion data of PR and VIRS and the retrieved cloud parameters. The characteristics of the cloud parameters of the precipitaiting clouds (precipitaiting clouds, PC) and the non-precipitaiting clouds (NPC) in the Northwest Pacific typhoon system are analyzed. The results show that: 1) the droplets of the descending and non dehydrating clouds in the typhoon system The difference in the effective particle radius (effective radius, Re) is small, while the optical thickness of PC (cloud optical thickness, for short, COT) is obviously higher than NPC, the former is more than 40~140, and the latter is more than 40:PC (Cloud water) is obviously higher than that of the threshold. The analysis of the relationship between the water probability and the cloud parameters shows that the probability of precipitation increases with the increase of the optical thickness and the cloud water path. With the increase of the effective particle radius of the cloud droplets, the precipitation probability increases first and then decreases. When the cloud water path is less than 1000 g/m2, the probability of precipitation increases with the increase of the cloud water path, with the cloud droplet. The size of the effective particle radius is independent: when the cloud water path is more than 1000g/m2, the precipitation probability is a function of the effective particle radius and cloud water path of the cloud droplets. On the whole, the large cloud droplet radius and the large cloud water path are easier to produce precipitation.3). The analysis results of the cloud parameter threshold recognition precipitation show that the optical thickness is greater than 40 and the cloud water path is higher than 120 g /ms and the optical thickness greater than the 40,10.8 micron channel are lower than 260K and the optical thickness is higher than 50. The three indexes are good for the recognition of precipitation. The TS score is 0.48,0.48 and 0.50., respectively. The threshold recognition method is also suitable for MODIS cloud products. It provides a new way for us to use satellite observation to identify water reduction,.2 typhoon and non typhoon precipitation. By analyzing the data of the JAXA/EORC tropical typhoon data set, the spectral features have been separated from the typhoon and non typhoon regions. Combined with the analysis of the fusion observation data of PR and VIRS, the results reveal the climatic characteristics of the typhoon and non typhoon precipitation in the East Asia during the 1998-2007 years and the characteristics of the infrared signal of the descending cloud: 1) the intensity of typhoon precipitation in East Asia. The degree spectrum is more wide than the non typhoon precipitation spectrum, especially the intensity spectrum distribution of the convective precipitation in the typhoon can be 5-20mm/h.2) the main form of the precipitation in East Asia is the non typhoon cloud precipitation, the frequency can reach 60%, the typhoon layer and the convective precipitation frequency are smaller, the maximum can reach 20% and 5%.3) and the vertical structure of typhoon and non typhoon precipitation is in the freezing layer. The difference of (~ 4 km) is obvious, the typhoon convective precipitation cloud decreases with the cloud top, the precipitation rate under the freezing layer decreases with the height, and the non typhoon convective precipitation is almost constant.4). The typhoon precipitation cloud is lower than that of the non typhoon dehydrating cloud, and the difference of the peak probability density of the two is up to the 15K.3 typhoon precipitation contribution. According to the data set from the best typhoon path provided by CMA, the seasonal variation, monthly and annual variation of typhoon precipitation in the Northwest Pacific region are studied by analyzing the TMPA 3B42 precipitation data of 3 hours and 0.250 resolutions. The results show that: 1) the typhoon precipitation contribution from the ocean is from the ocean to the ocean in the whole typhoon season (May to December). Inland decline, the ocean surface between 150N-250N can reach 40%, while the inland area is only 4%.. The contribution of strong typhoon to total precipitation is weaker than that of typhoon.2). On monthly scale, the contribution of monthly typhoon precipitation to local total precipitation is up to 60%. In August, the contribution of typhoon precipitation to the total Western Pacific Ocean total precipitation reached its peak (28%), and typhoon in August. The contribution of precipitation to total land surface precipitation reached its peak in December (23%).3). On the annual scale, the contribution of typhoon precipitation to the total Western Pacific Ocean Surface Precipitation reached its peak value in 2004 (~ 30%), and the contribution of the total precipitation to the land surface reached its peak in 1998 (to 20%).4). The precipitation contribution of typhoon precipitation in E1Nino and La Nina was great, and the typhoon dropped in El Nino year. The contribution of water to the neutral year increased by about 6%, while the La Nina year reduced the deep convective and penetrating convection of the 6%.4 typhoon and non typhoon system by analyzing the data of the PR precipitation profile of the PR from June to September, and the difference between the deep convection and the penetrating convective activity in the typhoon system and the non typhoon system in the Northwest Pacific region. The ratio of typhoon activities to the total convective and penetrating convective activities in the Northwest Pacific region is analyzed. The results show that: 1) deep convection and penetrating convective activity in the Northwest Pacific typhoon mainly occur on the ocean surface, with the highest frequency in the ocean surface between 15 degrees N-25 degrees, but not the typhoon middle deep convection and the penetrating convective activity in the Northwest Pacific. Frequent.2 in the surface of the land, the frequency of deep convective and penetrating convective precipitation in typhoon is lower, which is between 0.01% and 0.15% and 0.005% to 0.02%, respectively, but not in typhoon middle deep convection and penetrating convective precipitation, which can be up to 0.15% and more than 0.02%.3 respectively). The precipitation intensity in most areas is more than 14 mm/h and 22 mm/h respectively, and the spatial distribution is uneven. The intensity of non typhoon middle deep convection (penetrating convective) precipitation is smaller, mainly distributed in 10 mm/h ~ 14 mm/h (10 mm/h to 18 mm/h).4) and 2% to 30% is contributed by typhoon system in the Deep Convective Events on the Northwest Pacific Ocean. The proportion of movements increased significantly, and the proportion could reach above 50%.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P412.27

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