2013年12月浙北北部两次重度霾过程的对比分析

使用NCEP FNL资料对2013年12月浙北北部两次重度霾过程进行分析,结果发现,两次过程均与冷空气影响有关,发生前存在大范围污染物的持续积累,都是本地排放积累和周边污染传输的综合影响结果。两次过程发生的气象背景不同： 4日过程因静稳天气影响所致,污染物主要来自本地和周边（江苏中东部）的传输积累;26日过程与冷空气影响关系密切,为冷空气前锋携带大量污染物快速南下影响所致,污染物主要来源于黄淮平原远距离输入。边界层逆温有利于增强并导致重度霾发生。风廓线资料显示,边界层偏北风影响至地面时,重度霾发生。1500 m高度以下风力持续低于4级,重度霾和雾发展并持续;边界层风力增大至6级,重度霾消散。静稳天气下,污染物浓度变化与本地活动关系密切,过程中PM颗粒物共出现3个浓度高峰,而冷空气影响下,仅出现单个浓度高峰。     

温州一次重度霾天气过程分析

利用常规气象观测资料、探空站资料、环保部门提供的AQI监测数据,对2015年1月26—27日温州地区重度霾天气过程进行了综合分析。结果表明:此次重度霾过程影响时间之长,影响之严重,在温州霾气象记录中是十分罕见的;高空3层西北气流控制,风速较小,静稳天气,地面冷空气扩散南下,将浙北方污染物推至浙南,重度霾天气是由北方污染物输入和本地污染物叠加,地面存在弱辐合,近地面又存在逆温层不利于水汽和污染物在垂直方向扩散,利于大气颗粒污染物在浙南温州地区堆积,使得霾污染天气稳定维持;此后,冷空气主体南下,风速加大,气象扩散条件转好,污染物扩散至海上或福建,霾渐消散。     

2016—2017年冬季华北地区一次重污染过程的气象条件分析

以华北地区为研究区域,利用地面监测数据、高空观测资料、NCEP FNL资料及HYSPLIT后向轨迹模式,对2016年12月26日至2017年1月9日该地区的雾霾天气过程进行综合分析。结果表明,雾霾期间高空以纬向环流为主,冷空气势力偏弱,主要受高压、弱高压或均压场控制,有利于华北地区静稳天气形成。同时,雾霾期间边界层平均高度约600~900 m,污染物浓度与边界层高度呈负相关,且污染物浓度变化较边界层高度变化存在滞后现象。逆温层的长期存在,不利于污染物垂直扩散,能见度一直维持在5 km以下。后向轨迹集合模拟与聚类分析表明,以北京地区为核心的华北地区雾霾天气期间,外来污染物中,80%来自西北方气团,20%来自河北西南地区气团。     

河北中南部连续12 d重霾污染天气过程特征及影响因素分析

2013年12月14—25日,河北中南部地区发生了一次长达12 d的重霾污染天气过程。本文通过对同期气象条件、流场、污染物特征进行分析,探讨了这次过程的成因。此次污染过程与霾密切相关,具有持续时间长、范围广及强度大的特点;在静稳的大尺度气象条件和近地面大气层结下,污染物沿近地面风场的弱辐合区迅速积累,是重覆污染天气形成的关键;此次重霾污染天气过程中有两次弱冷空气活动,两次冷空气影响层次有所不同但影响时间均较短,不能彻底改变静稳大气层结,对污染物的扩散能力有限,重霾污染天气得以长时间持续。     

2019年湖南一次重污染天气过程成因分析

2019年12月12—17日,湖南省出现了一次首要污染物为PM2.5的持续时间长、影响范围大的重污染过程。本文综合应用湖南省环境监测站发布的AQI、逐小时主要污染物浓度和各类气象观测数据资料等,选取长沙为代表站,深入探究本次重污染天气过程气象条件、边界层演变特征等,并探讨污染物的来源和外来源气团移动路径。结果表明:此过程为输入叠加本地的复合型污染,污染积累阶段的弱冷空气打通了污染传输通道,有利于北方污染物南下,污染爆发阶段主要是本地静稳天气叠加上游外来源造成,污染清除阶段湖南地区地面主要是受较强冷空气影响,风力加大,污染物迅速稀释扩散,近地面逆温的存在是此次污染持续并爆发的重要条件。后向轨迹表明,此次重污染天气过程是外来源和本地源共同叠加的结果。     

达州市2016年元旦期间持续重污染天气气象条件分析

利用空气质量监测资料、高空和地面气象观测资料、NCEP再分析资料,对达州市2016年元旦节期间重污染天气过程特征及气象条件进行分析。结果表明:达州市此次重污染天气过程为长时间无冷空气活动,无降雨,大气污染物不断积聚形成。AQI日变化受污染源排放情况影响更大,早上低,白天逐渐增加,天黑后达到峰值。大气污染物的积累一般发生大气稳定度为中性或以上。AQI与08时和17时混合层厚度负相关,但日平均混合层厚度与AQI没有通过相关性检验。重污染时近地面有逆温层且逆温层较厚。AQI与逐日最高气温、日平均风速和日最大风速正相关,降雨对大气污染物稀释作用明显,特别是降雨持续时间长,雨量大效果更为显著。AQI逐时变化与温度正相关,与风速负相关。     

常州地区一次持续性霾天气过程分析

利用常规气象观测资料和NCEP再分析资料对2013年12月1—8日常州地区一次持续性严重霾天气过程进行了综合分析。结果表明:常州地区此次持续性霾天气过程中高纬地区高层环流较平直,低层为弱西南暖湿气流,冷空气势力较弱;2013年11月30日常州地区位于地面"L"型高压顶部,偏西风对常州上游地区污染物的输送和12月1日清晨出现的逆温层,导致扩散条件较差是此次霾过程爆发的主要原因;持续的地面均压场控制和频繁出现的逆温层为霾提供了维持机制,12月9日的强冷空气造成了此次霾过程消散。持续性霾天气过程期间,温度露点差减小,相对湿度增大,风力减小,多为偏西偏南风,且近地面多为弱的上升运动,为霾的维持提供了稳定的层结和充足的水汽。常州地区此次霾天气过程的主要污染物为颗粒物(PM2.5、PM10),部分SO_2、NO_2及O_3等污染物通过协同转化作用生成颗粒物,导致霾粒子浓度剧增是此次霾过程爆发的重要内因;后向轨迹模式的模拟结果也表明常州上游地区污染物的输送对此次霾过程亦有贡献。     

达州市2016年元旦期间持续重污染天气气象条件分析

利用空气质量监测资料、高空和地面气象观测资料、NCEP再分析资料,对达州市2016年元旦节期间重污染天气过程特征及气象条件进行分析。结果表明:达州市此次重污染天气过程为长时间无冷空气活动,无降雨,大气污染物不断积聚形成。AQI日变化受污染源排放情况影响更大,早上低,白天逐渐增加,天黑后达到峰值。大气污染物的积累一般发生大气稳定度为中性或以上。AQI与08时和17时混合层厚度负相关,但日平均混合层厚度与AQI没有通过相关性检验。重污染时近地面有逆温层且逆温层较厚。AQI与逐日最高气温、日平均风速和日最大风速正相关,降雨对大气污染物稀释作用明显,特别是降雨持续时间长,雨量大效果更为显著。AQI逐时变化与温度正相关,与风速负相关。     

2018年常州一次罕见持续性雾-霾天气分析

利用常规气象观测资料、探空资料、污染物浓度及AQI资料、NCEP再分析资料等,对2018年11月24日至12月3日夜间常州持续11 d的强浓雾和严重霾天气过程进行了分析。结果表明：（1）此次雾-霾过程持续时间长、范围广、强度大、污染重。（2）中纬度地区高层持续纬向环流控制、中低层暖脊稳定存在,地面持续受均压场或弱倒槽顶部、弱冷锋前部影响,是这次持续性雾-霾过程的重要天气条件。（3）边界层内弱辐散、负涡度及弱的下沉气流是此次雾-霾天气得以长时间维持、发展的动力因子。近地层长时间水汽饱和且维持小风速利于雾-霾的长时间维持。（4）近地面高强度的贴地逆温长时间维持和持续较低的混合层高度是此次雾-霾形成、发展和长时间维持的重要热力条件。雾比霾的平均混合层高度明显偏低且霾等级越高混合层高度越低,混合层高度的变化先于能见度变化,对雾-霾临近预警有较好的指导作用。（5）弱冷空气渗透、风速适当增加、混合层高度的先期快速下降、负净辐射曝辐量绝对值的明显增大是雾爆发性增强的主要原因。     

重庆主城区一次重度霾天气过程分析

利用NCEP再分析资料、L波段雷达探空资料、常规气象资料及自动气象站资料和空气污染资料,对2005年12月25-28日重庆主城区一次重度霾天气过程进行了分析.结果表明:此次重度霾天气过程发生在一定天气背景下,500 hPa青藏高原南侧南支槽槽区宽广,槽前西南气流较为强盛,850 hPa重庆地区持续处于均压场控制,气压梯度小,水平风速弱,且影响重庆地区的冷空气活动少、强度弱,有利于重度霾的形成和维持;低层风速较小、中低层逆温层的持续存在、气温较低也是此次重度霾形成和维持的重要条件;在未达到饱和的情况下,适当增加湿度有利于霾的加强,霾天气过程中,气溶胶粒子的吸湿增长会使能见度更加恶化.     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

<正>The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth’s climate and environment.     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.     

A COMPARATIVE ANALYSIS OF ATMOSPHERIC AND OCEANIC CONDITIONS BEFORE THE OCCURRENCE OF TWO TYPES OF EL NIO EVENTS

The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.     

IMPACT OF ATMOSPHERIC LOW-FREQUENCY OSCILLATION ON THE IMMIGRATION OF NILAPARVATA LUGENS(STL) IN HUNAN AND JIANGXI PROVINCES

Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.     

全球贸易隐含碳变化及其影响分析

基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;     

Information for Contributors

正Journal of Meteorological Research is an international academic journal in atmospheric sciences edited and published by Acta Meteorologica Sinica Press,sponsored by the Chinese Meteorological Society.It has been acting as a bridge of academic exchange between Chinese and foreign meteorologists and aiming at introduction of the current advancements in atmospheric sciences in China.The journal columns include Articles.Note and Correspondence,and research letters.Contributions from all over the world are welcome.