Track of Super Typhoon Haiyan Predicted by a Typhoon Model for the South China Sea

Super Typhoon Haiyan was the most notable typhoon in 2013. In this study, results from the operational prediction of Haiyan by a tropical regional typhoon model for the South China Sea are analyzed. It is shown that the model has successfully reproduced Haiyan’s rapid passage through the Philippines and its northward deflection after its second landfall in Vietnam. However, the predicted intensity of Haiyan is weaker than the observed. An analysis of higher-resolution model simulations indicates that the storm is characterized by an upper-level warm core during its mature stage and a deep layer of easterly flow. Sensitivity experiments are conducted to study the impact of certain physical processes such as the interaction between stratus and cumulus clouds on the improvement of the typhoon intensity forecast. It is found that appropriate boundary layer and cumulus convective parameterizations, and orographic gravity-wave parameterization, as well as improved initial conditions and increased horizontal grid resolution, all help to improve the intensity forecast of Haiyan.     

原油污染对栉孔扇贝抗氧化酶活性的影响

以原油水溶性成分(water soluble fraction of crude oil,WSF)为污染物,采用暴露实验法,研究了栉孔扇贝(Chlamys farreri)鳃和消化腺组织中超氧化物歧化酶(Superoxide Dismutase,SOD)和过氧化氢酶(Catalase,CAT)活性的变化.结果表明,WSF污染下,鳃和消化腺组织SOD和CAT酶活性随暴露时间增加一般表现为降低-升高-降低的趋势,酶活性达到最高的时间随浓度不同而变化.第1天时消化腺SOD在0.08 mg/L浓度下被诱导,而后随时间增加表现为抑制效应;浓度为0.21和0.88 mg/L时消化腺SOD酶活性被抑制,随暴露时间延长而活性增加.暴露时间为4d时,石油烃浓度在0.08和0.88 mg/L时鳃组织SOD酶活性均被抑制,而浓度为0.21 mg/L时被诱导.消化腺和鳃组织SOD可以作为扇贝被污染胁迫的指标.     

多通道地基微波辐射计在0713号"韦帕"台风登陆前后探测性能及特征分析

利用上海市气象局2007年9月进行的"韦帕"台风探测试验资料和地面常规观测资料,对多通道地基微波辐射计在0713号"韦帕"台风登陆前后探测性能及特征进行了分析。结果表明:多通道地基微波辐射计探测的温度和相对湿度趋势与GPS探空得到的基本一致,尽管二者之间存在一些小的差异,但也表明了微波辐射计对台风具有一定的探测能力。0713号"韦帕"台风登陆前后温度和水汽密度场上,甚短生命史的冷暖气柱和高水汽密度柱十分活跃,体现了"韦帕"台风登陆前后的阵性特征。     

The making and breaking of supercontinents: Some speculations based on superplumes, super downwelling and the role of tectosphere

The mechanisms of formation and disruption of supercontinents have been topics of debate. Based on the Y-shaped topology, we identify two major types of subduction zones on the globe: the Circum-Pacific subduction zone and the Tethyan subduction zone. We propose that the process of formation of supercontinents is controlled by super downwelling that develops through double-sided subduction zones as seen in the present day western Pacific, and also as endorsed by both geologic history and P-wave whole mantle tomography. The super-downwelling swallows all material like a black hole in the outer space, pulling together continents into a tight assembly. The fate of supercontinents is dictated by superplumes (super-upwelling) which break apart the continental assemblies. We evaluate the configuration of major supercontinents through Earth history and propose the tectonic framework leading to the future supercontinent Amasia 250 million years from present, with the present day Western Pacific region as its frontier. We propose that the tectosphere which functions as the buoyant keel of continental crust plays a crucial role in the supercontinental cycle, including continental fragmentation, dispersion and amalgamation. The continental crust is generally very thin, only about one tenth of the thickness of the tectosphere. If the rigidity and buoyancy is derived from the tectosphere, with the granitic upper crust playing only a negligible role, then supercontinent cycle may reflect the dispersion and amalgamation of the tectosphere. Therefore, supercontinent cycle may correspond to super-tectosphere cycle.     

夏季副热带波谱能量分析及南亚高压的维持

本文应用波数空间的能量方程、采用欧洲中心客观分析资料(ECMWF),讨论了1982年夏季副热带对流层上部的能量学特征,着重分析了南亚高压的维持。结果表明,副热带能量循环与热带不同,海陆不均匀加热对超长波动能的作用比较小。在纬向气流～波动相互作用中、绝大多数波都失去动能。通过波～波相互作用、超长波1～2波及短波11～16波向中间尺度传输能量。 南亚高压有效位能的主要来源是有效位能的垂直输送;动能的主要来源是气压梯度力的作功。南亚高压能量的主要耗散机制是通过非线性作用向尺度较短的波动传输。     

大地电阻率在超低频/极低频电波传播技术中的作用

介绍了大地电阻率在超低频 /极低频电波传播技术中所起的作用 ,指出发射天线场区具有高电阻率 ,是辐射有效超低频 /极低频电磁波的必要条件。在介绍了大地电阻率分布特点的基础上 ,提出了天线场区大地电阻率测量的思路和方法     

Analyses of Orissa Super Cyclone using TRMM (TMI), DMSP (SSM/I) and OceanSat-I (MSMR) Derived Data

The super cyclone in October 1999 was the most intense tropical cyclone in the last century in Orissa, a coastal state in India. This state was battered for more than two days by strong winds and intense rain killing thousands of people. The main objective of this study is to examine the impact of total precipitable water content (TPWC) and surface wind speed data from sensors on board the Tropical Rainfall Measuring Mission (TRMM), Defense Meteorological Satellite Project (DMSP), and Indian Remote Sensing Satellite (OceanSat-I) satellites on the data assimilation system at NCMRWF, New Delhi during the Orissa cyclone period. Comparison of various assimilation experiments suggests that the utilization of TRMM Microwave Imager (TMI) data in the assimilation produced the best analyses. However, in all the forecasts, the storm was predicted to weaken and did not have a reasonably good track. Assimilation experiments with the other two satellite data showed the cyclone track much to the south of the observed track and also it was a weak storm. Biases in the data, when compared with each other, are evident in the analyses also. Better analyses are obtained when the satellite data are used in the originally obtained resolution than when reduced by averaging. A forecast experiment with assimilated data, utilizing the Cloud Motion Vectors (CMVs) from METEOSAT along with TMI data, produced the best forecast among all the experiments. However, the forecast quality was poor. A high-resolution data assimilation experiment was carried out to see the impact of model resolution on the analyses of the cyclone. The strength of the cyclone further increased when higher resolution TMI data were included. The study highlights the need for more satellite data over the Indian Ocean, where conventional data coverage is too poor to define the vertical structure of the atmosphere.     

2017年5月14日合肥地区雷暴大风过程机理分析

利用地面、探空、机场自动观测、多普勒雷达等资料,以多普勒雷达数据产品为重点,对合肥机场及周边地区一次雷暴大风的成因进行了分析。结果表明：机场西北部两个对流风暴在3—6 km高度层合并,5 km高度处形成强反射率因子核,强反射率因子核高度10 min内迅速下降4 km,风暴内下沉气流在地面形成强冷池,强冷池的快速移动导致机场大风形成。下沉气流产生的初始原因是降水粒子的下降拖曳作用;吸入作用、水成物与环境间的负浮力增大、动量下传、补偿性气流的作用是下沉气流产生的重要原因。机场西南部的大风带由雷暴出流边界过境造成,出流边界破坏了边界层结构导致超折射现象的消失。风暴后部持续的冷空气补充和风暴前部源源不断的上升气流维持稳定的垂直环流,持续的下沉补偿气流导致机场东部大风的长时间维持。     

树脂催化合成丁酸异戊酯的研究

研究了大孔强酸性阳离子树脂高温催化合成丁酸异戊酯的影响因素 ,得出了最佳工艺条件 ,酸产率高达 96%以上。该法流程简短、操作简便、污染少 ,产品质量好 ,酯含量超过 98% ,是取代旧工艺的理想方法。     

辽宁开原强龙卷的卫星云图和雷达回波演变特征分析

利用葵花8号(Himawari-8)卫星资料、沈阳SC天气雷达数据、ERA5再分析资料及常规天气观测资料, 分析了2019年7月3日辽宁开原强龙卷的卫星云图、雷达回波演变及大气环流特征。结果表明: 此次开原强龙卷发生在东北冷涡底部, 低层850 hPa有明显的暖湿气流, 形成了“下湿上干”的垂直结构。3日17:00龙卷初生地0—6 km有22.8 m·s^-1、0—1 km有7.6 m·s^-1强垂直风切变。龙卷生成之前, 初生地西侧比东侧气温偏高, 存在2—5 ℃地面温度差。生成后, 移动路径东侧形成明显冷池, 最低温度19 ℃, 与西侧温差最大达11 ℃。龙卷生成时可见光云图上对流风暴的云砧水平尺度明显增大, 云顶升高、亮温降低。雷达回波演变特征表明, 龙卷对流风暴的发展经历了由多单体非强风暴发展到多单体强风暴再发展到超级单体风暴三个阶段, 龙卷在最强等级时有对流单体的合并。开原龙卷风暴在三个阶段都有中气旋, 17:11中气旋向下伸展到低层, 反射率因子出现指状回波。