TUVR型紫外辐射表性能研究

利用多台Eppley实验室的TUVR紫外辐射表, 设计并进行比对观测试验, 定量了解TUVR型辐射表测量误差来源及贡献, 了解该辐射表性能, 从而提出数据订正方法。试验结果表明:TUVR型辐射表测量误差来源于感应元件和散射片两部分; 感应元件的衰减率y与使用时间t (月) 呈线性关系。散射片的测量误差跟一个地区的污染状况有关。清洗后散射片透过率与原始水平的透过率仍能保持线性关系, 不影响其余弦订正能力。订正后的结果与标准测量值相关显著。     

一种绢云母样品的综合鉴定分析

运用X射线衍射、差热分析以及扫描电子显微镜等现代分析测试技术，对某地绢云母矿样品进行了综合分析，查明了该样品中矿物组成；证明样品中的粘土矿物成分是绢云母，而不是伊利石，为更好地对该绢云母资源进行开发利用提供了可靠的依据。     

由冬至夏北半球副热带地区大气热源的季节转换特征及其可能机制

本文基于多套卫星观测数据和ERA-Interim再分析资料,分析了由冬至夏北半球副热带地区大气热源的季节转换特征及其原因。结果表明,北半球副热带大陆东部以对流凝结潜热为主的夏季型大气热源首先于4月初在我国南方地区建立,该过程与江南雨季的形成发展联系紧密。2~3月,江南地区的大气热源以感热加热为主,这时降水以大尺度层云降水为主;而在4月初之后,江南地区降水以对流性降水为主,相应地对流凝结潜热成为大气热源的主要成分。动力和热力诊断分析说明,青藏高原南部热力状况的季节变化是导致4月初江南地区降水性质和大气热源首先发生季节转换的重要原因。2~3月,随着太阳辐射逐渐增强,青藏高原地面感热随之加强,此时对流层中部的纬向西风令江南地区的对流层中部暖平流加强,引起上升运动并加强局地大尺度层云降水,令土壤湿度加大,为随后局地对流性降水的快速发展提供了有利条件。之后,青藏高原地面感热在4~5月期间继续加强,这时高原南坡的"感热气泵"令其四周的低空水汽向北辐合,从而加强了江南地区的低空南风,使大量水汽自南海-西太平洋向北输送,令江南地区的对流性降水快速发展,地面感热迅速减小,对流凝结潜热进而成为江南地区大气热源的主要成分。     

SPATIO-TEMPORAL CHARACTERISTICS OF NO2 IN PRD URBAN GROUP AND THE ANTHROPOGENIC INFLUENCES ANALYSIS BASED ON OMI REMOTE SENSING DATA

Spatio-temporal distribution characteristics and variation trends of tropospheric NO_2 in Pearl River Delta(PRD) urban group and its adjacent areas were analyze from 2005 to 2013 based on remote sensing data from ozone monitoring instrument(OMI) satellite, and further explored the impact of human activities on NO_2. Compared with the ground observation data, the OMI NO_2 remote sensing data displayed high reliability. Due to active industrial production, high car ownership, great energy and power consumption, the average tropospheric NO_2concentration(7.4×1015molec/cm2) of PRD region is about 3 times of the adjacent areas. At the same time, the regional high pollution NO_2 in PRD region as a whole, the urban group effect is remarkable. Sinusoidal model can well fit the periodic variation of the NO_2 in PRD and adjacent areas. NO_2 concentration was highest in winter while lowest in summer. The concentration of NO_2 in PRD region is decreasing in recent 9 years, which has a significantly negative correlation with the second industry output and car ownership. This suggests that the nitrogen oxide emissions governance in PRD region had achieved initial results. The concentration of NO_2 increased significantly in the eastern and northern Guangdong Province, there are good positive correlations with the second industrial outputs and car ownerships, it is thus clear that industrial emissions and automobile exhausts are important sources of NO_2 in these regions. The concentration of NO_2 in western Guangdong area is stable.     

Observational and Mechanistic Analysis of a Nighttime Warm-Sector Heavy Rainfall Event Within the Subtropical High over the Southeastern Coast of China

In August 2021, a warm-sector heavy rainfall event under the control of the western Pacific subtropical high occurred over the southeastern coast of China. Induced by a linearly shaped mesoscale convective system(MCS), this heavy rainfall event was characterized by localized heavy rainfall, high cumulative rainfall, and extreme rainfall intensity.Using various observational data, this study first analyzed the precipitation features and radar reflectivity evolution. It then examined the role of e...     

STUDY ON THE VISIBILITY REDUCTION CAUSED BY ATMOSPHERIC HAZE IN GUANGZHOU AREA

In recent years the pollution of aerosol is getting worse and worse in Guangzhou area. The haze weather mainly occurs from October to April of the following year, resulting in visibility deterioration. From the beginning of the 1980's the visibility dramatically deteriorated, obviously increasing haze weather, in which there are three big fluctuations, respectively showing the periods of pollution of dust, sulphate and dust, fine particle from photochemical process and sulphate and dust accompanying the development of economy. The long-term tendency of visibility caused by fog and light fog does not have the tendency due to human activity or economical development and the variation mainly show the inner interannual and interdecadal variation of climate. The deterioration of visibility has close relation to the fine particles in Guangzhou area, with half of PM10 surpassing the limits set by national second graded standard, meanwhile, all values of PM2.5 rise above the day-mean limits of American national standard, indicating very high fine particle concentration. The ratio of PM2.5 to PM10 is also very high, reaching 62% - 69%, especially higher in dry seasons than in rainy seasons.     

大城市气溶胶对光化辐射通量及臭氧的影响研究(Ⅱ)——数值试验分析

城市化已引起大量痕量气态污染物、气溶胶以及臭氧前体物的人为排放,从而引起区域大气化学循环的扰动变化。在分析国内外研究现状与观测实例的基础上,进一步用辐射模式与化学模式研究了气溶胶对到达地面的光化辐射通量以及臭氧形成的影响,表明气溶胶可显著减小到达地面的光化学辐射通量,减缓光化学反应进程,并进一步抑制臭氧的形成;在目前广州等大城市的污染过程中,高浓度的气溶胶可造成光化学辐射通量衰减高达70%~80%,紫外线的衰减比可见光更明显,在可见光波段随波长增大衰减幅度减小,气溶胶层的存在对短波长激发的光化学过程的影响更加显著。分析说明城市污染大气中光化学反应的生成物与反应物之间存在自抑制过程,在目前的城市群复合污染情况下,气溶胶与臭氧之间的非线性相互作用值得关注。     

青藏高原夏季风强弱变化及其对亚洲地区降水和环流的影响——2008年个例分析

利用2008年多种台站观测和再分析资料,通过相关分析和合成分析,详细讨论了青藏高原夏季风季节内变化及其与印度夏季风和东亚夏季风降水之间的关系.结果表明:2008年高原夏季风爆发偏早,降水偏多,季风活动有明显的季节内振荡特征、其准双周振荡特征与东亚夏季风指数和印度全区降水振荡周期相似.高原夏季风强(弱)时,印度全区及我国...     

广东省能见度仪观测网优化设计

针对广东省的能见度观测展开研究,提出了适用于能见度观测布局适应性分布研究的新方案,旨在为器测替代目测的能见度监测网提供建议。研究表明:利用广东省86个地面气象观测站的2009—2011年能见度和相对湿度日平均值资料,计算得到了品质因数 (figure of merit,FOM指数) 和空间影响范围因数 (sphere of influence,SOI指数),并以此为依据对现有的能见度站点进行排名和分类。再根据确定的标准遴选所需站点,筛选时,如果排名低的站点影响的范围内超过50%的区域被排名高的站点影响范围所覆盖,则剔除此排名低的站点。筛选得到广东省能见度仪观测站网需要的最少站点数为43个。考虑到地形以及增加背景站等因素,最后综合考虑广东省能见度仪观测站网所需要的站点数为51个,该结果可为器测能见度观测站网建设提供参考。     

1961—2016年东北地区冬季寒潮事件变化特征及其对区域气候变暖的响应

利用东北地区1961—2016年164个气象台站逐日平均气温和最低气温数据,根据国家标准《寒潮等级》（GB/T 21987—2017）的单站冷空气等级,计算近56年来各单站不同等级冷空气过程的频次、强度、持续日数,应用趋势系数、Mann-Kendall检验、小波分析、相似系数等统计方法,研究了东北地区三种类型寒潮（超强寒潮、强寒潮、寒潮）的气候变化特征。结果表明：三种类型寒潮日数空间分布存在明显的地区差异,高海拔地区相对偏多,低海拔和平原地区相对偏少。年尺度上,1961—2016年三种类型寒潮日数和站次呈减少趋势,减少速率呈现为超强寒潮＞强寒潮＞寒潮;年代尺度上,三者均在20世纪60年代到70年代末期相对偏多,1980年开始进入一个相对偏少的时段,21世纪00年代中期以后有小幅度增加;寒潮日数和站次均存在明显的3~5 a短周期性变化。1961—2016年东北地区冬季气温在空间变化上全区呈一致的增加趋势,66%的站点增温显著,检测到冬季气温的突变点为1981年。东北地区气候变暖后,三种类型寒潮日数和站次均有明显的减少。