Surface ozone concentration variability in Moscow and Kiev

The comparison is represented of the results of surface ozone concentration measurements in two megalopolises, Moscow and Kiev. A temporal course of ozone concentration and temperature in both cities is close by the shape and is typical of medium-polluted plain stations. In both megalopolises, two maxima are observed within the seasonal ozone concentration variability, in spring and summer, and during the day, a usual ozone concentration maximum (approximately in 2–3 hours after the local noon) and the night one being typical of big cities. An average ozone concentration and an average temperature in corresponding periods are higher in Kiev than in Moscow. Evidently, the summer maximum is associated with photochemical ozone generation processes, and the spring one, with dynamic processes of its transport in the atmosphere. In both megalopolises, the episodes are observed in the warm period under meteorological conditions being unfavorable for the pollutant scattering in the atmosphere when the ozone concentration exceeds the threshold limit value and is dangerous for health. The repeatability of such episodes is the highest one in July-August. In Kiev, such episodes are more frequent than in Moscow. An effective statistical model is constructed for both megalopolises in which the observed ozone concentration is represented in the form of regression function of temperature and relative humidity.     

A method of carbon monoxide emission forecast in Moscow

Proposed is a method of operational forecast of carbon monoxide distribution in Moscow based on the data on the power and distribution of its sources. Described is a method of computation of carbon monoxide emission to the atmosphere based on the data on its concentration. It is demonstrated that the emissions computed by this method can be used as the input data for chemistry transport models. Carried out is a number of numerical experiments with the COSMO-ART model. The results of model simulations are in good agreement with the observational data. The developed method of computation of carbon monoxide emissions enables to realize the operational short-range forecast of its concentration.     

Peculiarities of seasonal variations of atmospheric aerosol concentration in the surface air of Moscow environs

The seasonal variations of the concentration of particles of different sizes in the atmospheric surface layer are studied on the basis of the data of daily measurements of atmospheric aerosol characteristics in the town of Dolgoprudny (20 km from the center of Moscow) carried out in 2006–2009. It is revealed that the steady variations of monthly mean aerosol concentration are observed within the particle diameter interval of 0.02–1 μm. The annual course of concentration of these particles has two maxima, in February-March and in September–October, and one minimum in June. The concentrations of particles with the size of 0.01–0.02 μm defined by the general atmospheric background and the concentrations of particles of >1 μm associated with the local sources do not have clearly pronounced seasonal variations. It is shown that the regularities of the annual concentration variations of particles with the size of 0.02–1 μm are mainly explained by the sign and value of the lapse rate in the layer up to 925 hPa that indicates the prevalence of the vertical mixing in the processes of aerosol scattering in the surface layer as compared with the horizontal transfer.     

WRF ARW and CHIMERE models for numerical forecasting of surface ozone concentration

Results of joint calculations with meteorological WRF ARW model and chemistry transport CHIMERE model are considered as a basis of the modern system of the air quality assessment and forecasting. The system was designed in the Russian Hydrometeorological Center and Institute of Applied Physics of the Russian Academy of Sciences. Detailed prognostic information about the atmosphere state provided by the WRF ARW was used in the CHIMERE model for describing the air mass transport processes, chemical transformation, and pollution deposition. Results of retrieval and forecast of surface ozone concentration as one of main air quality indicators are under consideration. Calculations of ozone concentrations for different configurations of a prognostic system differ in resolution of model grid and in the way the boundary conditions are prescribed.     

Statistical model for downscaling extreme surface temperatures at the weather station network in the Moscow region

Investigation of predictability of extreme meteorological values is an urgent problem of the present time. The purpose of this work is to demonstrate possibilities of reconstructing daily maximum and minimum air temperatures on a city scale using short-range weather forecasts. A statistical model is suggested, with which more than 85% of the natural variability of the extreme temperature at the Moscow weather stations can be reconstructed. A possibility to predict the maximum outliers in the solutions is demonstrated. The necessity to use the procedures of filling up the available gaps in observational data is emphasized. A classification of extreme situations in the atmosphere is suggested, which will help to increase the accuracy of the solution.     

Statistical characteristics of concentration fluctuations in dispersing plumes in the atmospheric surface layer

Measurements have been made of concentration fluctuations in a dispersing plume from an elevated point source in the atmospheric surface layer using a recently developed fast-response photoionization detector. This detector, which has a frequency response (–6 dB point) of about 100 Hz, is shown to be capable of resolving the fluctuation variance contributed by the energetic subrange and most of the inertial-convective subrange, with a reduction in the fluctuation variance due to instrument smoothing of the finest scales present in the plume of at most 4%.Concentration time series have been analyzed to obtain the statistical characteristics of both the amplitude and temporal structure of the dispersing plume. We present alongwind and crosswind concentration fluctuation profiles of statistics of amplitude structure such as total and conditional fluctuation intensity, skewness and kurtosis, and of temporal structure such as intermittency factor, burst frequency, and mean burst persistence time. Comparisons of empirical concentration probability distributions with a number of model distributions show that our near-neutral data are best represented by the lognormal distribution at shorter ranges, where both plume meandering and fine-scale in-plume mixing are equally important (turbulent-convective regime), and by the gamma distribution at longer ranges, where internal structure or spottiness is becoming dominant (turbulent-diffusive regime). The gamma distribution provides the best model of the concentration pdf over all downwind fetches for data measured under stable stratification. A physical model is developed to explain the mechanism-induced probabilistic schemes in the alongwind development of a dispersing plume, that lead to the observed probability distributions of concentration. Probability distributions of concentration burst length and burst return period have been extracted and are shown to be modelled well with a powerlaw distribution. Power spectra of concentration fluctuations are presented. These spectra exhibit a significant inertial-convective subrange, with the frequency at the spectral peak decreasing with increasing downwind fetch. The Kolmogorov constant for the inertial-convective subrange has been determined from the measured spectra to be 0.17±0.03.     

Periodic variability of surface ozone concentration over western and central Europe from observational data

Characteristics of periodic variability of surface ozone concentration at 98 western and central European stations participating in the EMEP program for at least 7 (up to 14) years are determined. Daily and hourly model concentrations of surface ozone for each station are given in an analytical form that presents a sum of a constant constituent and basic harmonics that determine ozone concentration variability throughout a year and a day. A 12-month harmonic, whose maximum is observed in the spring period (in Northern Europe it is observed 1 to 2 months earlier than in Southern Europe) dominates in the energy spectrum of seasonal variability of daily mean ozone concentration at most stations. The energy part of higher (6-and 4-month) harmonics is the largest at the stations close to the sea and ocean coasts. Higher harmonics largely influence the time of the ozone extremum formation, shifting it towards the summer, or even forming a second (summer) maximum, whose magnitude at a number of stations (in Italy, Hungary, in the south of Germany, and in some others) exceeds the spring maximum. A 24-hour harmonic dominates in the energy spectrum of daily ozone variability. The maps of a “normal” distribution of surface ozone fields and their standard deviations for different seasons and time of the day have been compiled based on the model characteristics. The “norms” derived can be used to detect anomalies in the temporal trend of the surface ozone and to validate its climate changes.     

Distribution of surface ozone concentration in the clean areas of china and its possible impact on crop yields

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Simulation of stratospheric ozone in global forecast model using linear photochemistry parameterization

The two types of ozone, the simulation with interactive (prognostic) ozone using linear photochemistry parameterization (LPP) (INTR) and the simulation with non-interactive ozone using ozone climatology (CLIM), were used in the global forecast model. These two types of ozone were compared with ozone observations from the Aura Microwave Lim Sounder (MLS) and ozonesondes from 16-30 September 2008. The INTR is sensitive to LPP schemes while less sensitive to the time average of initial ozone data. Among three LPP schemes, CARIOLLE, COPCAT, and LINOZ, the COPCAT produces ozone profiles with least differences from MLS and ozonesondes. CLIM overestimates MLS at 200-20 hPa while INTR with COPCAT scheme underestimates MLS ozone above 5 hPa. Over the Antarctic in the lower stratosphere CLIM overestimates MLS and ozonesondes whereas INTR underestimates MLS but overestimates the ozonesonde data. Thus, COPCAT agrees better with ozonesonde data than any other LPP schemes and CLIM. Changing the ozone distribution from CLIM to INTR affects temperature profiles mainly through the modification of differential radiative fluxes. The correlations between ozone, differential radiative fluxes, and temperature are distinguished by altitude (or pressure levels). The correlations are strong or moderate between 3-1000 hPa (lower atmosphere) and weak above 3 hPa (upper atmosphere). This study demonstrates that the simulation of ozone using an appropriate LPP scheme is excellent in overcoming the drawbacks of using climatological ozone profiles that poorly agree with observations in extreme ozone hole events.     

Complex forecast of surface meteorological parameters

The statistical scheme using the results of the best foreign global schemes and the COSMO-RU7 regional scheme is proposed for forecasting surface temperature for five days and the amount of precipitation for three days. Presented are the estimates of prognostic values of the surface air temperature and amount of precipitation for the period of July 2010–June 2013. The joint statistical taking account of different types of systematic errors in the complex forecasting scheme enables excelling all initial schemes in quality. A scheme of the complex forecast is operationally used and its results are daily updated on the website of the Hydrometcenter of Russia at 09:15. The forecasts of extreme temperature, dew-point temperature, and wind speed near the surface are also presented on the website.     

秦皇岛市气温与近地面臭氧浓度的关系分析

利用2013年1月至2014年12月和2017年1月至2019年6月秦皇岛市近地面臭氧（O₃）浓度数据和气象资料,采用广义相加模型（GAM）,运用回归分析方法和基于R语言的统计分析软件,控制气压、相对湿度、日照时数、总云量等要素的混杂效应及时间变化趋势,分析春季、夏季、秋季、冬季气温与O₃浓度的关系。结果表明：秦皇岛市O₃浓度夏季最高、春季次之,冬季最低,与气温变化趋势基本一致,呈现明显的季节变化。各季气温与O₃浓度呈非线性相关关系,拟合曲线存在拐点,拐点两侧相关效应存在明显差异,主要表现为春季日平均气温高于15.0℃时,气温每升高1℃,O₃浓度增加7.6 μg·m^-3,增长速率是气温低于15.0℃时的4.0倍;夏季日平均气温高于27.2℃时,气温每升高1℃,O₃浓度增加13.9 μg·m^-3,增长速率是气温低于27.2℃时的11.6倍;秋季日平均气温高于21.4℃时,气温每升高1℃,O₃浓度增加47.5 μg·m^-3,增长速率是气温低于21.4℃时的19.1倍;冬季O₃浓度偏低且变化较为平稳,气温对O₃浓度的变化影响不大。由于春夏两季O₃浓度基础值偏高,因此,夏季和春季气温偏高时O₃浓度快速增加现象应引起高度重视。     

Persistent high concentration of ozone during windstorm conditions in southern Korea

Summary Prior to and following the development of a windstorm in the mountainous coastal area of southern Korea, ground level ozone (O₃)-concentrations near Kangnung city, on the lee side of the mountains, show a maximum value at approximately 1300 LST, owing to a photolytic cycle of NO₂–NO–O₃ during the day and a minimum in concentrations at night as a result of the reverse cycle. During the development period of the windstorm, ozone concentrations are generally high all day, and slightly higher during the night. This distribution pattern of ozone is very different from the typical distribution of ozone in the absence of windstorms. High daytime concentrations of ozone during the windstorm are due to both the increase in the amount of ozone from photochemical reactions involving NO_x and the increase in O₃-concentration due to a decrease in the convective boundary layer thickness under the influence of downslope windstorm conditions on the lee-side of the mountains. At night, the windstorm increases in intensity as the westerly winds combine with a katabatic wind blowing downslope toward the surface at the coast. This causes momentum transport of air parcels in the upper levels toward the surface at the coast and the development of internal gravity waves, which generate a hydraulic jump directed upward over the coast and the East sea, thereby reducing to very thin the thickness of the nocturnal surface inversion layer (NSIL). The higher O₃-concentration at night depends mainly upon the shallow NSIL and on some O₃ being transported by the momentum transfer from the upper troposphere toward the ground in windstorm conditions.     

Observed and calculated variability of the particulate matter concentration in Moscow and in Zelenograd

The results of a comparative analysis of temporal and spatial variations in the particulate matter (PM₁₀) concentration are under consideration; the information is obtained based on the measurement data from the Mosekomonitoring network of stations and results of calculations with the CHIMERE chemistry transport model adapted for the Russian central region. The intercomparison of measurement data obtained in summer 2007 and respective calculations showed that the model provided a satisfactory reproduction of the observed temporal variability of the daily mean PM₁₀ concentration (an averaged correlation coefficient is 0.8), but systematically underestimated the absolute values of the PM₁₀ concentration. It is shown that model data quality can be significantly improved due to a simple a priori correction of the model errors. Irregularities in the spatial distribution of the PM₁₀ concentration and their dependence on meteorological conditions were revealed. The reasons of the formation of episodes of a high PM₁₀ concentration are considered.     

斯堪的那维亚臭氧亏损和地面加热

对ＮＡＳＡ的ＴＯＭＳ臭氧资料进行分析后指出：冬季在北极的斯堪的那维亚地区存在一个明显的臭氧亏损区，亏损区的中心值达－５０ ＤＵ，相当于该区域平均值的 １５％。对臭氧亏损和北大西洋海温的东西向差异作相关分析得到：其季节变化的相关系数为－０．９６，逐月（ １６８个月）变化的相关系数为－０．７０。同样对臭氧亏损与地面加热进行相关分析后指出：斯堪的那维亚地区的臭氧亏损和该地区地面的热通量关系极其密切，其相关系数均在－０．８７以上。由此我们认为：北大西洋暖流向北输送能量，引起斯堪的纳维亚地区地面加热，由此造成了冬季该地区的臭氧亏损。     

基于TIGGE多模式降水量预报的统计降尺度研究

利用TIGGE资料中欧洲中期天气预报中心、美国国家环境预报中心、英国气象局以及日本气象厅4个中心,1~7 d预报时效的降水量预报资料,以TRMM/3B42RT降水量作为"观测值",对东亚地区降水量进行统计降尺度处理。首先利用逻辑回归方法将天气分为有雨和无雨,再对有雨的情况,利用线性回归方法对插值后的预报结果进行降尺度订正,最后将4个中心的预报值进行消除偏差集合平均,得到多模式集成的降水量预报场。结果表明:逻辑回归能够有效地改善预报中小雨的空报情况,统计降尺度订正后的预报结果比直接插值更加准确,多模式集成的预报效果优于单模式结果,其改进效果随预报时效的延长逐渐减小。     

Long-term measurements of surface ozone in the German Democratic Republic

The ozone concentration near the earth's surface has been measured at some stations in the GDR for more than 30 yr using the wet chemical method. Even at rural stations the ozone data show a significant linear increase by about 1–3% yr^–1. The ozone increase being stronger in summer than in winter is assumed to be due to photochemical ozone production from increasing anthropogenic emissions of trace gases that are transported over long distances. A weaker ozone increase by only about 0.2% per year was observed in the free troposphere (5.5 km) from balloon-soundings at Lindenberg within the period 1975–1984. If the ozone trends continue, the ozone concentration near the surface and its seasonal amplitude will have doubled around the turn of the century as compared to the mid-fifties.     

Results of surface ozone monitoring in the atmosphere over Ulan-Ude

Presented are the results of surface ozone monitoring in the atmosphere over Ulan-Ude during the period from 2000 to 2012. Revealed are seasonal and diurnal variations of surface ozone. The analysis of the seasonal variability of surface ozone concentration indicates the presence of the clearly pronounced maximum in spring-summer period. A statistical model of forecasting single concentrations of the surface ozone is considered using the multiple regression analysis. Temperature, relative humidity, wind direction, wind speed, turbulence factor, temperature gradient, velocity of vertical flow, and concentrations of minor gas admixtures such as nitrogen oxides are used as predictors. Analyzed are statistical relationships, where observed ozone values are presented in the form of the regression function of the most significant predictors.     

影响北京夏季O3污染的O3前体物浓度及天气条件分析

根据2003年北京夏季近地面大气光化学污染物观测资料,对中国气象局培训中心(代表站)O3超标日浓度、O3前体物浓度、不同天气条件下O3浓度分布特征等进行分析。结果表明:中国北京夏季NO2,NO,CO的浓度特征与日本神奈川县相似,白天(16:00以前)如果NO2/NO超过29,则容易出现O3超标;VOC浓度的高低影响O3浓度;当处于暖湿气流控制,地面为小风或静风、气温较高、湿度较大的多云天气时,易出现O3超标情况。这些污染物发生的特点和规律对北京大气光化学污染的研究和防治具有借鉴意义。