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1.
珠江三角洲地区的灰霾天气研究进展 总被引：10，自引：0，他引：10
珠江三角洲地区是我国气溶胶污染较严重的地区之一,也是国内较早开展灰霾天气研究的地区,从灰霾标准、科学概念、长期变化趋势、细粒子污染本质、水平输送和垂直扩散能力以及气溶胶的光学特性和物理化学特性方面进行了研究。结果表明,近年来珠江三角洲地区的气溶胶污染日趋严重,气溶胶云一年四季都出现,且长期稳定存在,重污染区位于珠江口以西的珠江三角洲西侧。灰霾天气主要出现在10月至次年4月。灰霾导致能见度恶化。自20世纪80年代初开始,该地区的能见度急剧恶化,灰霾天气显著增加,其中有3次大的波动,分别代表珠江三角洲经济发展相伴随的粗颗粒气溶胶污染、硫酸盐+粗颗粒气溶胶污染、光化学过程的细粒子+硫酸盐和粗颗粒气溶胶的复合污染时期。雾和轻雾造成的低能见度的长期变化趋势,没有由于人类活动影响或经济发展影响带来的趋势性变化,其波动主要反映了气候波动固有的年际和年代际变化。珠江三角洲能见度的恶化主要与细粒子关系比较大,PM10有一半年份的年均值超过国家二级标准的年均值浓度限值(70μg m–3),而细颗粒物(即PM2.5)各年都超过国家二级标准的年均值限值(35μg m–3),尤其是有些年份年均值浓度超过标准限值的2倍,细粒子浓度甚高。另外,近年细颗粒物占PM10的比重非常高,可达57%~79%,黑碳气溶胶浓度非常高,月均值达到5.0~9.1μg m–3,黑碳气溶胶污染严重。和20余年前的资料相比较,细粒子在气溶胶中的比重有明显增加,有机碳和硝酸盐、铵盐的占比增加,而硫酸盐占比略有减少,钙占比明显减少。区域气流停滞区的形成是发生严重灰霾天气的主要气象条件,垂直输送能力不足也是加重灰霾天气的气象条件之一。 相似文献
2.
气溶胶消光作用是影响大气能见度的主控因素,气溶胶浓度、成分与其散射和吸收特性的非线性关系导致其对能见度的影响存在较大不确定性。1988～2008年美国IMPROVE(Interagency Monitoring of Protected Visual Environments)能见度监测网络各区域的重构细颗粒物(RCFM)浓度范围为1.4～19.4μg m–3,重构气溶胶消光系数为10.0～172.5 Mm–1(1 Mm–1=10–6 m–1)。2006～2018年中国各地区已有观测的平均细颗粒物PM2.5浓度为14.3～188.3μg m–3,对应的重构消光系数为52.6～1044.0 Mm–1。美国地区PM2.5浓度水平与我国三亚地区相当;硫酸盐是气溶胶消光的最大贡献成分,占比可高达77%;其次是有机物,最大可达50%;而硝酸盐只有在南加州对气溶胶消光的贡献较大,超过了30%。同时,由于东部的相对湿度高于西部,东部和西部的消光差异... 相似文献
3.
2013年1月华北地区重雾霾过程及其成因的模拟分析 总被引：14，自引：6，他引：8
2013年1月11~14日,华北地区经历重雾霾过程。为了探讨其形成原因,利用大气化学模式系统Weather Research and Forecasting(WRF)-Chem模拟2013年1月华北地区气溶胶的时空变化。模拟的能见度、气象要素(温度、湿度、降水、风速和风向)以及细颗粒物(PM2.5,大气中直径≤2.5μm的颗粒物)地表浓度的时间变化与近地面观测值都较为吻合。模拟结果表明,1月11~14日,细颗粒物高值分布于河北省南部和东部、天津地区以及北京地区,其日均值约为400~500μg m–3。通过与历史气候数据比较发现,2013年1月10~15日华北地区的气象条件表现为较大的相对湿度正距平(20%~40%)以及风速的负距平(-1 m s–1)。北京站点的探空数据还表明,在1月11~13日期间,垂直方向上,1 km以下的大气中存在明显的逆温层,并且湿度保持较高的值(80%~90%)。模拟结果表明,1月11~14日,近地面南向风和东向风将水汽输送到华北地区,上层大气(850hPa)的西北风则将沙尘输送到华北地区。以上气象条件有利于气溶胶的吸湿增长和浓度的聚集。硝酸盐的收支分析表明,在北京地区,与1~9日相比,10~14日夜间化学生成和传输的显著增加都贡献于硝酸盐浓度,是重雾霾形成的主要原因。 相似文献
4.
天津冬季重霾污染过程及气象和边界层特征分析 总被引：3，自引：2，他引：1
京津冀大气灰霾污染严重,天津市作为其核心组成之一其污染形势亦严峻。选取2013年2月20~28日天津重霾污染时段7站PM2.5(空气动力学当量直径小于等于2.5μm的颗粒物,即细颗粒物)和气态污染物数据,结合北京污染数据、地面气象要素、能见度、边界层温湿和风廓线、后向轨迹,深入分析重霾污染过程特征及气象和边界层成因。结果显示,研究时段天津PM2.5、SO2、NO2、CO和O3浓度均值为150、87、56、2.4和22μg m-3,气态污染物各站差异显著,但仅有SO2全面超过国家空气质量一级标准(50μg m-3),而PM2.5具有区域同步变化特征,且严重超标,是一级标准(35μg m-3)的2~8倍,最高小时均值高达364μg m-3;高浓度PM2.5是导致低能见度的主因,能见度小于10 km对应PM2.5阈值为50μg m-3。弱风和高湿度导致局地排放累积,PM2.5始增,在高湿度条件下,持续偏南风促使其稳步增加,配合弱北风和弱东风PM2.5震荡上扬,污染高值阶段,南北气流短时迅速切换,区域污染传输叠加污染的循环累积,PM2.5浓度峰值达到最高;除因边界层强东风导致的平流逆温外,高浓度PM2.5与平流逆温密切相关;高污染时段高湿主要集中在500 m以下,且随高度递减幅度较大;位于200~600 m的低空急流一定程度抑制污染上升,尤其持续强东风使PM2.5浓度稳步降低到二级水平,污染迅速有效清除最终依赖整层的强西北风。北京、环绕天津的河北中部和西南部地区对天津重污染有显著贡献。 相似文献
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广州地区旱季一次典型灰霾过程的特征及成因分析 总被引：18，自引：1，他引：17
通过研究2009年11月广州市气溶胶颗粒物质量浓度(PM10、PM2.5、PM1)、黑碳浓度、散射系数(Scatter)等大气成分要素,以及微波辐射计、激光雷达及风廓线雷达所探测的风、温、湿等边界层结构,统计分析广州旱季一次典型灰霾过程(2009年11月23—29日)中气溶胶颗粒物及其光学特性的时空变化特征,并配合天气形势背景、边界层结构对其形成原因进行详细分析。在典型灰霾过程中,黑碳浓度高达58.7μg/m3,散射系数高达1 902.7 Mm-1,PM10浓度高达423.5μg/m3,PM2.5浓度高达355.7μg/m3,PM1浓度高达286.5μg/m3。通过对同期的气象条件分析表明在广州地区旱季,区域性污染过程,特别是灰霾天气的形成具有以下三种气象条件:大气边界层高度较低;高压变性出海的天气形势与之密切相关;在偏东和偏南气流带来的高湿度环境下,气溶胶吸湿增长效应显著,导致出现严重灰霾天气。 相似文献
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《气象与环境学报》2016,(6)
基于2015年秋末冬初华北地区频繁出现的大范围重污染天气过程,利用无人直升机搭载的气溶胶采样装置和激光粒子计数器对北京顺义及房山地区近地面大气颗粒物进行探测,分析了重雾霾天气大气颗粒物的质量浓度和数浓度廓线及其分布特征。结果表明:北京地区重雾霾天气过程粒径小于1.0μm的气溶胶数浓度随高度变化不明显,粒径大于1.0μm的气溶胶数浓度随高度呈弱的减小趋势,说明重污染天气条件下近地面层大气颗粒物的粒子数相对稳定,亚微米级气溶胶数浓度较高,而粗粒子气溶胶数浓度较低。基于无人直升机搭载的气溶胶采样装置采集的气溶胶样品的质量浓度廓线表明,50 m高度大气颗粒物质量浓度较高,最大浓度达700μg·m-3。 相似文献
7.
珠江三角洲大气灰霾导致能见度下降问题研究 总被引：153，自引：6，他引：153
大气气溶胶的气候效应和环境效应研究是当今国际科技界的热门话题。近年来珠江三角洲地区的气溶胶污染日趋严重,一年四季长期稳定存在气溶胶云,重污染区偏于珠江口以西的珠江三角洲西侧。灰霾天气主要出现在10月至次年4月。大气灰霾导致能见度恶化。自20世纪80年代初开始,该地区的能见度急剧恶化,灰霾天气显著增加,其中有3次大的波动,分别代表与珠江三角洲经济发展相伴随的气溶胶污染、硫酸盐加气溶胶污染、光化学过程的细粒子加硫酸盐加气溶胶的复合污染时期。雾和轻雾造成的低能见度的长期变化趋势,没有由于人类活动影响或经济发展影响带来的趋势性变化,其波动主要反映了气候波动固有的年际和年代际变化。珠江三角洲能见度的恶化主要与细粒子关系比较大,PM10有一半月均值超过国家二级标准的日均值浓度限值(150μg/m3),而PM2.5月均值全部超过美国国家标准的日均值浓度限值(65μg/m3),尤其是10月至次年1月的月均值浓度几乎超过标准限值的1倍,细粒子浓度甚高。另外PM2.5占PM10的比重非常高(58%—77%),尤其是旱季比雨季更高。与15a前的资料相比较,细粒子在气溶胶中的比重有明显增加,因而在目前珠江三角洲的气溶胶污染中,主要是细粒子的污染。 相似文献
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气象—化学双向耦合模式（WRF-NAQPMS）研制及其在京津冀秋季重霾模拟中的应用 总被引：10，自引：2，他引：8
为解析大气污染物与气象的双向反馈机制及其对气象和环境的影响,建立基于Mie散射理论的气溶胶—光学性质模块,研制气象-化学双向耦合器,以嵌套网格空气质量预报模式NAQPMS(Nested Air Quality Prediction Modeling System)为基础,建立了NAQPMS和中尺度气象模式WRF(Weather Research and Forecasting Model)的双向耦合模式(WRF-NAQPMS)。利用此模式数值模拟了2013年9月27日至10月1日的北京-天津-河北地区一次秋季严重灰霾过程。结果表明,考虑气溶胶辐射反馈的双向耦合模式模拟的气象要素和细颗粒物(PM2.5)浓度与观测结果更为一致。灰霾期间,气溶胶直接辐射效应显著改变了边界层气象要素,北京-天津-河北地区地面接收的太阳短波辐射减少25%,2 m高度的温度平均下降1°C,湍流动能下降20%,10 m高度的风速降低超过0.2 m/s,边界层高度下降25%,使得边界层大气更加静稳,进而造成了重污染地区污染进一步加剧,如石家庄近地面细颗粒物浓度增加可达30%。分析表明灰霾与边界层气象要素之间存在一种正反馈机制,采用该机制的双向耦合模式有利于准确模拟和预报灰霾污染过程。 相似文献
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北京冬季雾霾事件的气象特征分析 总被引：4，自引：3，他引：1
利用观测的气象要素和细颗粒物(即PM2.5)浓度资料,并结合中尺度数值天气模式WRF(Weather Research and Forecasting Model),对2013年1月北京地区雾霾污染期间天气条件和边界层气象特征进行了分析。模拟与观测对比表明,WRF模式可以较好地反映北京—天津—河北地区地面和高空主要气象要素的时空分布。对1月10~14日、27~31日两次重雾霾天气的分析表明,雾霾的形成是高浓度的大气颗粒物和特殊的气象条件共同作用的结果。小风或静风、稳定的大气层结,使大气扩散能力减弱,造成污染物堆积,偏南气流将周边污染物和水汽输送到北京,不仅增加了污染物浓度,而且有利于气溶胶吸湿增长,消光增强,使能见度下降,进而形成雾霾。 相似文献
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The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
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Yuepeng PAN Mengna GU Yuexin HE Dianming WU Chunyan LIU Linlin SONG Shili TIAN Xuemei Lü Yang SUN Tao SONG Wendell W. WALTERS Xuejun LIU Nicholas A. MARTIN Qianqian ZHANG Yunting FANG Valerio FERRACCI Yuesi WANG 《大气科学进展》2020,37(9):933-938
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on 相似文献
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Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
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Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
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Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
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《大气和海洋科学快报》2013,(4):227
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. 相似文献
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《大气和海洋科学快报》2014,7(6):F0003-F0003
AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
18.
《大气和海洋科学快报》2014,(5):F0003-F0003
AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气科学进展》2014,(6)
正Aims Scope Advances in Atmospheric Sciences(AAS)is an international journal on the dynamics,physics,and chemistry of the atmosphere and ocean with papers across the full range of the atmospheric sciences,co-published bimonthly by Science Press and Springer.The journal includes Articles,Note and Correspondence,and Letters.Contributions from all over the world are welcome. 相似文献