2014-2017年成都市大气污染特征分析

利用2014年5月~2017年12月的成都市环境空气质量监测资料,分析了成都市空气污染情况及污染物浓度时空变化特征。结果表明:成都市空气质量以优良天气为主,市区的首要污染物以PM2.5为主,郊区以O3为主;灵岩寺监测点的PM2.5,PM10,NO2和CO四种污染物的质量浓度低于成都市区各监测点,O3的质量浓度高于成都市区各监测点,SO2的质量浓度值与成都市区各监测点相差不大;成都市各监测站点六种污染物质量浓度具有明显的年际变化、季节变化、月变化和日变化趋势,且成都市区各监测点的变化趋势比较一致。     

兰州市低空风时空变化特征及其与空气污染的关系

对1988年至1992年兰州市环境监测站自动监测系统监测到的近地面逐时风和空气污染浓度资料以及对应时段的兰州市低空风资料乃至城，郊近40年的地面风资料做了深入的分析，并将城区与郊区对照点（榆中站）进行对比研究，揭示了风向频率变化特征和风速日变化，年变化，年际变化以及风随高度的变化规律。同时分析了对应时段空气污染的分布状况及其与风速的相关关系，为研究兰州市边界层大气动力稳定度的时空变化规律和开展空气污染预报提供了一定的依据。     

Solar Activity and Algal-bloom Occurrences in the Northern Adriatic Sea: Geomagnetic Connection

Summary The high-speed particle flux (solar wind) escaping from the Sun controls the geomagnetic activity at middle latitudes. The latter is found to be negatively correlated to the difference of atmospheric pressure between January and April averaged out in the area of the Northern Adriatic. This difference is again related to the water volume flowing from the South into the Northern Adriatic Sea and is a necessary (though not sufficient) condition for the occurrence of strong algal-blooms in summer. A physical model involving geomagnetic activity, mean atmospheric pressured difference between latitude 35 °N and 55 °N in the European area and atmospheric pressure difference from winter to spring in the Northern Adriatic basin is proposed. The possibility of predicting the long-term variations of geomagnetic activity allows one to obtain long-term predictions of winter minus spring pressure and therefore indications of the risk of strong summer-time algal-bloom episodes. Received March 29, 1996 Revised February 14, 1997     

Pseudo-global warming projections of extreme wave storms in complex coastal regions: the case of the Adriatic Sea

This numerical work aims to better understand the behavior of extreme Adriatic Sea wave storms under projected climate change. In this spirit, 36 characteristic events—22 bora and 14 sirocco storms occurring between 1979 and 2019, were selected and ran in evaluation mode in order to estimate the skill of the kilometer-scale Adriatic Sea and Coast (AdriSC) modelling suite used in this study and to provide baseline conditions for the climate change impact. The pseudo-global warming (PGW) methodology—which imposes an additional climatological change to the forcing used in the evaluation simulations, was implemented, for the very first time, for a coupled ocean–wave–atmosphere model and used to assess the behavior of the selected storms under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 greenhouse gas projections. The findings of this experiment are that, on the one hand, the AdriSC model is found capable of reproducing both the Adriatic waves associated with the 36 storms and the northern Adriatic surges occurring during the sirocco events and, on the other hand, the significant wave heights and peak periods are likely to decrease during all future extreme events but most particularly during bora storms. The northern Adriatic storm surges are in consequence also likely to decrease during sirocco events. As it was previously demonstrated that the Adriatic extreme wind-wave events are likely to be less intense in a future warmer climate, this study also proved the validity of applying the PGW methodology to coupled ocean–wave–atmosphere models at the coastal and nearshore scales.

     

Precipitation in the Central Mediterranean during the last century

Summary Monthly precipitation data from 10 stations (Patras, Corfu, Hvar, Trieste, Venice, Florence, Rome, Naples, Catania and Malta) in the Central Mediterranean area are used for a period of 95 years (1894–1988). The homogeneity of these precipitation time series is tested and their statistical characteristics are analysed. An abrupt climatic change is found at Naples and Rome. The application of Principal Component Analysis (PCA) has yielded three groups of stations where the precipitation data indicate similar fluctuations. Group A includes the stations situated along the coasts of the Ionian and Adriatic seas and the station Naples, while Group B includes the Northern Italian stations and Group C includes the stations at Catania and Malta. In all three groups maximum precipitation was observed during the 1930s. The periodicities of the scores of the significant components have been studied by spectral analysis and significant periodicities of 13.6, 3.5 and 2.2 years were found. Finally, a discussion of the relationships between these precipitation fluctuations and circulation types over the Mediterranean is presented.With 5 Figures     

广东阳江沿海地区海陆风观测结果及其特征分析

根据我国广东阳江某大型电力工程项目前期工作中获取的气象资料，分析了该地区海陆风环流特征。结果表明该地区海陆风频率较高，但相当一部分环流较浅（尤其是春季）；海风持续时间平均为9－10小时；白天的海风比夜间的陆风要强得多，高空回流层的气流强度远小于地面入流层的强度；海陆风环流结构比较特殊，其上下层风向间以及白天的海风风向和晚上的陆风风向间大多有较大夹角，不易形成重复污染。     

Application of statistical method in pollution episode analyses

Observed pollutants are of both primary and secondary origins, influenced by local topography and meteorology. Identifying sources and relative contribution often require vast detailed data collection and complicated models. This study applied a statistical time series analysis to two selected pollution events, spring and fall, at two sites in northern Taiwan. Vector moving average representations were used to quantitatively examine relationships among chemical pollutants and estimate their lifetimes. Results from impulse responses show that wind direction change alters the characteristic of pollution observed in opposite sites of Taipei City, from chemical dominant system to transport dominant one and vice versa. Chemicals are clearly separated into photochemical pollutants and primary pollutants. Results pointed out that Taipei City is the major source of photochemical smog, but not these primary pollutants. Derived chemical lifetimes at same location vary from 20% to four times under different meteorological condition. Estimated concentrations of hydroxyl radical range between 2 to 8 × 10⁷ cm⁻³. Photochemical pollutants are responsible for parts of PM10 collected in both station observed. Oxidation of SO₂ is only important in PM10 observed at one station. This study provides a simpler tool to derive information usually from complex models, therefore, is suitable as complement in decision-making process.     

ERA-40-aided assessment of the atmospheric influence on satellite retrieval of Adriatic Sea surface temperature

The aim of this work is assessment of regional atmospheric influence on satellite derivation of Adriatic Sea surface temperature (SST). To this end the European Centre for Medium-Range Weather Forecast (ECMWF) ERA-40 reanalysis dataset has been employed to provide the temperature and humidity profiles and surface data, while the RTTOV 8.7 radiative transfer model was used to calculate the top-of-atmosphere brightness temperatures for the advanced very high-resolution radiometer (AVHRR) channels. Ten ERA-40 grid points over the Adriatic Sea were used in the analysis, providing 29,590, 00 UTC and 12 UTC, clear-sky profiles. Climatological analysis of the ERA-40 profiles demonstrated distinct seasonal variability over the Adriatic Sea. Seasonality noted in the temperature and specific humidity profiles also evinced in the atmospheric transmittance, thermal channels temperature deficit, and derived γ and ρ parameters. A multivariate analysis was applied to relate the simulated top-of-atmosphere brightness temperatures to the Adriatic SSTs in order to generate exploratory sets of SST retrieval coefficients. All derived coefficient sets exhibited smaller noise amplification factor than the global counterpart. A test comparison of satellite-derived SST with an 11-month in situ SST series showed than locally derived coefficients provide smaller scatter (improved precision), and skin-centred bias that requires additional adjustment. Almost identical SST residual and error metric was obtained with seasonally adjusted classical split-window coefficients and with coefficients explicitly accommodating water-vapor dependence. Comparison with data reinforces the notion that the atmosphere over the Adriatic may exhibit variability that cannot be fully accommodated by globally adjusted correction.     

Impact of Air Pollution on Summer Surface Winds in Xi''an

By analysis of observation data,this paper demonstrates that pollution particles could reduce surface wind speed through blocking solar radiation to the ground.The comparation between temperature at the lowland meteorological station Xi'an and that over the nearby highland station Mt.Hun suggests that surface solar radiation at Xi'an is reduced due to the increasing anthropogenic aerosols.The reduced surface energy suppresses the atmospheric instability and convective flows,and thus the downward transfer of faster winds aloft is reduced.Consequently,wind speeds near surface are weakened.This reduction of surface winds is shown by the significant reverse trends of wind speeds over the two stations at different elevations.The aerosols' effects on winds are also manifested in the trends of radionsonde wind speed.The decreased surface winds in Xi'an have also reduced local pan evaporation.     

2015-2019年贵港市臭氧污染特征及其与气象要素的关系

为研究贵港市O3(臭氧)污染特征及其与气象要素的关系,对2015-2019年贵港市国家空气自动监测站和同期贵港国家气象观测站逐日、逐时气象资料进行了研究和分析.结果表明:近5a来贵港市O3污染日趋严重;O3污染存在明显的季节变化,秋＞夏＞春＞冬;O3浓度日变化特征呈单峰型,8:00出现谷值,15:00-16:00出现峰...     

乌鲁木齐市SO2浓度的分布及其可能原因

根据乌鲁木齐市 1994～ 1997年 SO2 浓度和气象监测资料 ,分析了 SO2 浓度的时空分布特征及其可能原因 ,并对各监测点 SO2 污染等级作出了评价。     

2006—2008年秋季广州市重大气污染过程特征研究

利用地面图、高空天气图(850 hPa、500 hPa)以及气象要素对2006—2008年秋季(9—11月)广州市4次典型的大气污染过程进行研究,分析其大气污染过程的特征及其相对应的天气系统、与气象要素之间的关系。结果表明,广州市秋季重大气污染多数发生在:(1)广州受冷空气影响或回暖期,持续小风或出现静风会导致污染物大量积聚,且多出现能见度明显下降;(2)由于偏北风的输送作用,处于下风向的万顷沙站较易出现重大气污染过程,表现出明显的区域性污染输送特征;(3)冷高压脊、回流天气形势、台风外围下沉气流影响期间;(4)近地面层出现逆温层或等温层。     

伊犁地区酸雨状况分析

利用伊宁国家基准气候站13a的酸雨资料,对伊犁地区酸雨状况进行了统计分析,参考其它的气象资料和环境资料对于伊犁的酸雨状况所代表的空气质量现状进行了分析论证。结果表明伊犁地区酸雨有很明显的季节特点,冬季最为严重,其中供热燃煤是最重要的原因。     

2007—2012年呼和浩特市Ⅲ级轻微污染日及以上天气特征分析

文章依据呼和浩特市环保监测站提供的本市每日空气质量实况日均值,对呼和浩特市2007—2012年Ⅲ级轻微污染以上日的空气质量变化进行了分析。结果表明,近6a(2007—2012年)里,按照国家《环境空气质量标准》(GB3095-1996),呼和浩特市Ⅲ级轻微污染以上日数逐年减少,空气质量逐年好转;呼和浩特市Ⅲ级轻微污染以上的首要污染物年际和季节变化较显著;强沙尘或沙尘暴天气是导致呼和浩特市出现严重污染的主要灾害性天气因素。     

我国霾和光化学污染观测研究进展

霾和光化学污染已成为我国最严重的环境气象灾害,受到政府和公众广泛关注。针对我国的环境气象问题,国内外科研人员开展了大量研究工作,发表了一系列的研究成果。该文对近年来我国霾和光化学污染的观测、分析和影响研究方面的文献进行综述,为将来相关研究提供基础。在霾污染方面,主要回顾了霾的现象与判别、组成与来源、影响霾的气象因素、霾的长期趋势等方面的研究进展。在光化学污染方面,主要回顾了污染的特征与水平、污染的区域化、臭氧垂直分布、地面臭氧影响因素、臭氧污染发展趋势等方面的研究进展。此外,还概括了霾和光化学污染危害研究主要成果,在文献综述的基础上,提出了未来研究中值得关注的几方面问题,包括进一步加强霾和雾的科学判识方法、污染物相互作用、污染-气象-化学-生态间耦合效应研究,特别关注光化学污染发展态势,加强长期观测资料的积累、分析与应用等。     

Waterspouts of the Adriatic, Ionian and Aegean Sea and their meteorological environment

The synoptic and mesoscale conditions associated with waterspout occurrence in the Adriatic, Ionian and Aegean Sea are examined in an attempt to quantitatively assess the meteorological environment favourable to the development of waterspouts. For this study, synoptic circulation patterns have been examined for 28 waterspout events in the central-eastern Mediterranean. The waterspouts were reported within the summer and fall of 2002, from July to November, a period of unusually high whirlwind activity. The Adriatic was most active during July, August and September and the Ionian and Aegean during September, October and November. Of the examined waterspout cases, 13 out of the total of 28 were found to be fair-weather waterspouts, while 15 represent tornadic events. For waterspout days, the frequency and distribution of four basic synoptic types, namely, south-west flow (SW), long-wave trough (LW), closed low (CLOSED) and short-wave trough (SWT), were investigated. The particular synoptic features that contributed to the development of waterspout activity were examined, based on five selected waterspout case studies. The mesoscale environment was explored using thermodynamic indices, moisture and wind parameters as derived by operational soundings from the nearest sites (preferably upwind) and closest in time to the waterspout occurrences. The results present an analysis of waterspout types in conjunction to thermodynamic and wind parameters for the purpose of determining synoptic patterns and mesoscale conditions most relevant to waterspout occurrences in these sea areas of the Mediterranean.     

玉林市2019年秋季一次臭氧污染过程特征分析

利用NCEP再分析、资料及空气自动监测站和micaps探空等资料,运用天气学分析和统计方法,对2019年9月24日至10月1日广西玉林一次臭氧污染过程的天气形势、热力动力特征及气象条件进行了分析。结果表明,受副高控制及台风外围下沉气流影响,高低层一致偏北风的稳定天气形势导致高温晴朗天气持续,利于臭氧浓度增加;垂直方向上多层逆温,扩散条件差,导致污染物在低层积聚;臭氧浓度与相对湿度、最大风速呈负相关,与日照时数呈正相关。     

黄山黟县双套自动观测站数据的质量评估

利用2011年2月安徽省黄山市黟县试点双套自动观测气象站(A站和B站)和黟县本站(Z站,自动站)的气象要素(气温、气压、风速、相对湿度、地温等)观测资料,进行了对比分析,并对自动气象站仪器换型后数据的连续性进行了全面的评估。评估的内容为:数据的完整性和差异性,其中,差异性通过均值、标准差、误差率、粗差率和一致率得到体现。评估的结果表明:1)双套自动站观测数据的可靠性较好,大多数要素接收率高达100%,B站湿度接收率较低,只有83.3%,是由于B站的相对湿度传感器故障造成的;2)双套站观测的多要素有较好的一致性,但AB、AZ的地温差值和AB的气压差值一致率较低,部分要素差值存在少量的奇异值;3)T-检验表明,双套自动站的观测数据与历史序列无显著差异,连续性很好;4)双套自动站可用于气象业务观测,但还要进行一定时间的并行运行,以便日后更好地对数据进行对比分析和订正。     

北京一次持续霾天气过程气象特征分析

2013年1月10-14日,北京平原地区出现了水平能见度在2 km以下、以PM_2.5为首要污染物、空气质量持续5 d维持在重度以上污染水平的霾天气。综合分析此次霾天气过程的天气形势、北京地区常规和加密气象资料以及城郊连续观测的PM_2.5浓度资料。结果表明：此霾过程期间,北京高空以平直纬向环流为主,受西北偏西气流控制,没有明显冷空气南下影响北京地区,地面多为不利于污染物扩散和稀释的弱气压场;大气层结稳定、风速小(日平均风速小于2 m·s^-1)、相对湿度较大（日平均相对湿度在70 %以上）、逆温频率高强度大,边界层内污染物的水平和垂直扩散能力差;北京城区及南部的京津冀地区人类活动排放污染物强度大,在相对稳定和高湿的天气背景下,受地形和城市局地环流的影响,北京本地污染物累积和区域污染物输送以及PM_2.5细粒子在高湿条件下的物理化学转化等过程共同作用造成此次北京城区及平原地区污染物浓度快速增长并持续偏高,高浓度PM_2.5对大气消光有显著影响,造成低能见度和持续霾天气。     

Sea/land breeze climatological characteristics along the northern Croatian Adriatic coast

Summary Climatological characteristics along the northern Croatian Adriatic coast have been examined for nine meteorological stations for the summertime sea/land breeze circulation. The stations considered are Pula-airport, Opatija, Rijeka, Senj, Malinska, Rijeka-airport, Mali Lošinj, Rab and Zadar. The hourly surface measurements at each station from June to September for the period 1991–2004 as well as the radiosoundings in Zadar (from 2002 to 2004) were used for the analysis. A dataset with the sea/land breeze days was formed according to the several criteria. The mean daily maxima of both air and sea surface temperatures were more influenced by the large scale disturbances toward north (e.g. in Rijeka or Opatija) compared to the values for e.g. Zadar. Furthermore, the influence of the large scale disturbances diminished toward the south concerning the sea–land temperature difference only at the stations placed at Rijeka Bay and Velebit channel. The strongest sea breeze was found at Pula-airport and the most frequent ones at Opatija and Zadar. At Senj the rarest, the weakest and the shortest sea breeze was observed. The climatological records of wind speed and air-sea temperature difference (ΔT) showed for Opatija, Malinska and Zadar that the maximum measured wind speed is around 4.5 °C confirming the nonlinear relationship between the sea breeze speeds and the ΔT during the day. At most stations, the clockwise rotation of the hodographs prevails which is typical for the Northern hemisphere due to Coriolis force, with the exception at Senj and Malinska. While the hodographs for Pula, Rijeka-airport and Mali Lošinj display a later onset of the prevailing sea breeze because of the interaction among several sea breeze circulations, the results for Opatija, Zadar and Senj show considerably distorted hodographs because of the nearby channeling of the air flow.