Methane, carbon monoxide, and carbon dioxide concentrations measured in the atmospheric surface layer over continental Russia in the TROICA experiments

The principal statistical regularities typical of the behaviors of the CH₄, CO, and CO₂ concentrations in the atmospheric surface layer over the continental Russian territory are revealed from the measurements performed in 1997–2004 along the Trans-Siberian Railroad from Moscow to Khabarovsk with a mobile laboratory. The data obtained under the conditions of the atmosphere free of anthropogenic pollutants are analyzed. For near-background conditions, the typical continental methane, carbon monoxide, and carbon dioxide concentrations and characteristic features of their large-scale spatial distributions and daily variations, including those caused by surface inversions, are determined. Variations in the concentrations of these trace gases over industrial regions are analyzed. Our results are compared to the data obtained at background stations of the world network of atmospheric monitoring and to the data of a numerical simulation.     

<Superscript>222</Superscript>Rn concentrations in the atmospheric surface layer over continental Russia from observations in TROICA experiments

Both space and time variations in the ²²²Rn concentration in the atmospheric surface layer over continental Russia were analyzed on the basis of data obtained in the Transcontinental Observations into the Chemistry of the Atmosphere (TROICA) experiments. The measurements were taken from a mobile laboratory which was part of a passenger train moving along the Trans-Siberian Railway from Moscow to Vladivostok. The factors that affect the spatial distribution of both daily and seasonal variations in the concentrations of ²²²Rn in the surface air were determined: atmospheric vertical stability, geological features of the area under study, and atmospheric precipitation. The influence of temperature inversions on the accumulation of ²²²Rn in the atmospheric surface layer was analyzed. The fluxes of ²²²Rn from the soil into the atmosphere were estimated for different regions of Russia.     

珠江口大万山海域大气总悬浮颗粒物中微量元素富集因子特征及物源解析

利用2014年秋季珠江口大万山海域大气气溶胶样品,分析了总悬浮颗粒物中微量元素(Cu、Pb、Zn、Cd、Fe、Cr和As)的含量,根据调查结果,利用富集系数法对微量元素的来源进行了分析。结果表明,Cu、Pb、Zn、Cd、Fe、Cr、As来源环境具有相同或相似性。调查海域大气颗粒物中的Pb、Zn、Cd和As含量相对于地壳均表现为强富集,富集系数远远大于10,属于污染元素,主要来自人类活动污染。珠江口大万山海域、辽东湾海域、青岛海域和东海海域这四个海域海洋大气中Pb、Zn和Cu的富集系数依次降低的顺序是一致的。整体而言,珠江口大万山海域Pb、Zn和Cu元素的富集因子相较国内其它海域低,但Cd的富集因子较高,达1000以上,受人类活动影响很大。     

Ozone and nitric oxides in the surface air over northern Eurasia according to observational data obtained in TROICA experiments

The results of the 1995–2008 observations of the concentrations of ozone and nitric oxides in the surface air over the Trans-Siberian Railway using a mobile laboratory (the TROICA experiments) are analyzed. The features of the spatial distribution and time variability of these gases over the continent within the latitudinal belt 48°–58° N are revealed individually for polluted and background conditions. The characteristic features of their distribution are a decrease in the concentration of nitric oxides and an increase in the concentration of ozone in an eastward direction. On the whole, the process of photochemical ozone formation over the territory of Siberia is slow. Noticeable increases in the concentration of ozone are associated with both forest and steppe fires and with the transboundary transport of pollution from the countries of eastern Asia. The dry precipitation of trace gases plays a significantly larger role in Siberia than in coastal and high-altitude unpolluted regions due to powerful and long temperature inversions.     

Modeling of Atmospheric Disturbances over the Crimean Mountains

Izvestiya, Atmospheric and Oceanic Physics - In using the nonlinear analytical model of the flow over the mountains, orographic disturbances and model adequacy are studied. Theoretically calculated...     

台湾海峡MERIS数据大气校正研究

根据MERIS(Medium Resolution Imaging Spectrometer,中等分辨率成像光谱仪)L1B产品特点,以台湾海峡为研究区域,开展MERIS数据大气校正研究。在阐述水色遥感数据大气校正原理的基础上,首先进行水体像元提取和辅助参数空间内插,获取大气校正所需的数据集。接着进行耀斑反射率计算和校正并利用加倍法精确计算瑞利散射。最后针对台湾海峡水体为清洁到轻度浑浊,提出先区分水体类别,再分别利用epsilon指数外推法进行一类水体气溶胶散射计算,和利用神经网络法计算二类水体离水反射率即ρw的方法。对大气校正的结果进行ρw负值像元数统计和光谱分析表明,该方法不仅降低ρw为负值的像元数,而且使大气校正后水体的光谱曲线同现场数据保持较好的一致性。     

A quasitropical cyclone over the Black Sea: Observations and numerical simulation

A long-living mesoscale cyclone observed over the Black Sea in September 2005 was characterized by a high wind velocity (25 m/sec) and induced an abnormal lowering of the sea-surface temperature (by more than 10°C). We performed the numerical simulation of this cyclone by using the MM5 model and the data of global operative analysis. The evolution of the cyclone and its structure similar to the structure of a tropical cyclone are reproduced. The primary azimuthal and secondary radial circulations, the clear-sky eye with warm core at medium levels, and the eyewall with strong air updraft and intense convection and precipitation are well visible. The fluxes of sensible and latent heat on the sea surface played the key role in the initiation and development of this cyclone. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 3, pp. 41–55, May–June, 2008.     

Observations of the von Karman constant over open-ocean waves

Forty-six open-ocean observations of the von Karman constant k , estimated from the momentum flux, wind velocity, and air temperature differences observed at the Argus Island tower, yielded an average value of 0.40±0.18 for |Ri|⩽0.014, where Ri is the gradient Richardson number. This average value agrees with the determinations of k over land by U. Hogstrom (1988) and S.F. Zhang et al. (1988). Scatter in these oceanic data sets may be due in part to ocean-wave influence as well as to instrumental and statistical variability     

Forecast of Convective Events and Its Verification against Atmospheric Electricity Observations

Izvestiya, Atmospheric and Oceanic Physics - A regional system of a short-term forecast of hazardous convective phenomena within WRF-ARW is described. It is shown that major maxima of errors in...     

Studying of biogenic volatile organic compounds in the atmosphere over Russia

The volatile organic compounds (VOCs) emitted from vegetation into the atmosphere play an important role in atmospheric chemistry and participate in the formation and growth of aerosol particles that affect the atmospheric radiation balance and the earth’s climate. A number of VOCs, such as isoprene, monoterpene, methylvinylketone, and methacrolein, whose surface concentrations were measured between Moscow and Vladivostok in the course of the Transcontinental Observations into the Chemistry of the Atmosphere (TROICA-12) experiment in July–August 2008, are considered. For the first time in Russia, a PTR-MS proton mass-spectrometer was used to measure the VOC concentrations. The continuous series of VOC concentrations in the atmosphere over the Trans-Siberian Railway were obtained, and the characteristic features of their variations were determined. The spatial distribution of the concentrations of biogenic VOC was compared with a map of Russia’s forests. It was found that the maximum concentrations of isoprene between Moscow and Vladivostok correspond to the zones of broad-leaved forests in the Far East and Primorskii Krai, and the maximum concentrations of monoterpene correspond to coniferous forests in Siberia. The obvious correlation between the concentrations of isoprene and the total concentration of methylvinylketone and methacrolein was revealed.     

Atmospheric trace gas measurements during SEEDS-II over the northwestern pacific

Atmospheric trace gas measurements were conducted during SEEDS-II. Atmospheric dimethylsulfide (DMS) was continuously measured by GC-MS during the R/V Hakuho cruise. Further, ambient air was sampled into canisters (42 samples) and analyzed by GC-MS and GC-FID for various biogenic and anthropogenic volatile organic compounds (VOCs) after the cruise. CO, O₃, SO₂, and NOx were monitored continuously aboard the ship.A fertilization experiment was conducted in a high-nitrate, low-chlorophyll (HNLC) region (48°N, 165°E). The atmospheric concentrations inside a patch (fertilized area) were compared with those outside it (natural area); however, clear differences were not observed for biogenic trace gasses (DMS, CH₃Cl, CH₃I, isoprene, and alkenes) in the atmosphere. However, a high DMS concentration was observed over the northwestern Pacific Ocean. The fertilized area was also observed by R/V Kilo Moana, and DMS was measured by GC-FPD. A good agreement was observed between the results of the measurements made aboard the two independent ships by different measurement methods.The atmospheric SO₂ concentration was compared with the atmospheric DMS concentration. The SO₂ concentration was found to vary with the atmospheric DMS concentration. A diurnal variation of the atmospheric DMS concentration was observed around the fertilized region. The DMS content tends to increase during the night and decrease during the day. A box model calculation was conducted to explain the diurnal variation of the atmospheric DMS. Since there was no diurnal variation of the wind speed, a constant DMS flux from the ocean surface was assumed. Further, the atmospheric OH radical concentration was assumed to be dependent on sunlight. The box model can roughly reproduce the atmospheric DMS diurnal variation mainly caused by its removal reaction with OH radicals.     

南海区域红外波段大气透过特征分析

利用MODTRAN大气辐射传输模型,输入我国南海区域大气廓线数据,对比分析气溶胶对红外波段大气透过特性的影响。研究表明,气溶胶、温度和季节对该波段在大气中传输均有一定影响;南海区域大气透过率随季节变化很大,夏季比冬季小10%以上,00时大气透过率略大于12时;采用近似国外模式大气带来的误差最大可达到50%以上。该研究结果充分说明:在红外波段大气透过率计算中引入实际大气廓线数据具有重要的军事和工程应用意义。     

Time Variations in the Composition of Atmospheric Aerosol in Moscow in Spring 2020

Izvestiya, Atmospheric and Oceanic Physics - The results of an intensive complex experiment carried out from March 25 to May 3, 2020, to study the composition and time variability of urban aerosol...     

Study of the formation of the methane field in the atmosphere over northwestern Russia

Major processes of generation of the methane field in the atmosphere over northwestern Russia have been studied on the basis of measured surface concentration and total content of methane in the environs of St. Petersburg, air-mass trajectories, and a three-dimensional regional pollution transport model. It is shown that the contribution of methane emission from an industrial center to the total column amount of methane is no more than 2% of its average value. At the same time, because of this emission, the surface methane concentration in the environs of St. Petersburg varies by as much as 50%. The origin of air masses arriving at the site of measurements influences both the total content and the surface concentration of methane. The air masses that passed over the continental part of western and eastern Europe are characterized by the values of total content and surface concentration of methane that are about 4% higher than those in the air masses formed over the ocean, which come to the region from the northwest. The regional transport model for greenhouse gases satisfactorily describes the results of surface measurements and adequately simulates observed tendencies in the change of total methane content. An estimate of the integral emission of methane into the atmosphere from St. Petersburg and its industrial suburbs is about 100 kt per year.     

Effects of the equatorial quasi-biennial oscillation in the total ozone content over Russia

On the basis of ground-based measurements of total ozone content (TOC) over Russia and a number of neighboring states during 1973–2002, the amplitudes and phases of TOC variations caused by the quasi-biennial oscillation (QBO) of wind in the equatorial stratosphere are estimated for different regions and for the whole area. The seasonal dependence of the QBO effect in the TOC is analyzed. It is shown that the magnitude and even the sign of the effect depend on the relation between the equatorial QBO phase and the season. The regional empirical models of seasonally dependent QBO effects are constructed. It is found that the seasonal dependence of regional effects accounts for 4% (in the north of the area) to 20% (in the south) of the interannual variability of the TOC. The relation between the QBO effect and the 11-year cycle of solar activity is analyzed. Significant differences are revealed in the effects under the conditions of maximum and minimum solar activity. The QBO effects obtained from observations at Russian stations, satellite measurements with a TOMS instrument, and spectrometric observations of the TOC at western European stations are compared, and their satisfactory agreement is shown. An analysis of the results suggests that the QBO effects in the TOC over Russia are caused by several interacting factors and apparently reflect their regional properties.     

Aerosols over the Arabian Sea: Atmospheric transport pathways and concentrations of dust and sea salt

This paper provides an overview of dust transport pathways and concentrations over the Arabian Sea during 1995. Results indicate that the transport and input of dust to the region is complex, being affected by both temporally and spatially important processes. Highest values of dust were found off the Omani coast and in the entrance to the Gulf of Oman. Dust levels were generally lower in summer than the other seasons, although still relatively high compared to other oceanic regions. The Findlater jet, rather than acting as a source of dust from Africa, appears to block the direct transport of dust to the open Arabian Sea from desert dust source regions in the Middle East and Iran/Pakistan. Dust transport aloft, above the jet, rather than at the surface, may be more important during summer. In an opposite pattern to dust, sea salt levels were exceedingly high during the summer monsoon, presumably due to the sustained strong surface winds. The high sea salt aerosols during the summer months may be impacting on the strong aerosol reflectance and absorbance signals over the Arabian Sea that are detected by satellite each year.     

Water-vapor content in the atmosphere over European Russia during the summer 2010 fires

We study the water vapor (WV) content over European Russia (ER) during the period of forest and peatbog fires in July–August 2010 using total column water vapor observations from MODIS instruments (both Aqua and Terra platforms) as well as aerological data and NCEP/NCAR reanalysis. It is found that the spatial distribution of total column water vapor (TCWV) over ER in this period was anomalous, with the WV excess in the north of the territory and its deficit in the south of ER. The relationship between WV variations, atmospheric dynamics and the fire situation is analyzed. Along with the processes of the WV advection and evaporation we evaluate the contribution of pyrogenic emission of WV in spatial-temporal evolution of WV over ER during wildfires. The changes of water vapor at different heights in the troposphere and stratosphere are investigated. The results of a comparative analysis of WV contents during the periods of summertime atmospheric blockings in 1972 and 2010 are also presented. The near-infrared total-column precipitable water MODIS products (L3) are validated by upper-air radiosonde data.     

Determining the Gravitational Gradient Tensor Using Satellite-Altimetry Observations over the Persian Gulf

With the advent of satellite altimetry in 1973, new scientific applications became available in oceanography, climatology, and marine geosciences. Moreover, satellite altimetry provides a significant source of information facilitated in the geoid determination with a high accuracy and spatial resolution. The information from this approach is a sufficient alternate for marine gravity data in the high-frequency modeling of the marine gravity field quantities. The gravity gradient tensor, consisting of the second-order partial derivatives of the gravity potential, provides more localized information than gravity measurements. Marine gravity observations always carry a high noise level due to environmental effects. Moreover, it is not possible to model the high frequencies of the Earth's gravity field in a global scale using these observations. In this article, we introduce a novel approach for a determination of the gravity gradient tensor at sea level using satellite altimetry. Two numerical techniques are applied and compared for this purpose. In particular, we facilitate the radial basis functions (RBFs) and the harmonic splines. As a case study, the gravitational gradient tensor is determined and results presented in the Persian Gulf. Validation of results reveals that the solution of the harmonic spline approach has a better agreement with a theoretical zero-value of the trace of the Marussi gravitational gradient tensor. However, the data-adaptive technique in the RBF approach allows more efficient selection of the parameters and 3-D configuration of RBFs compared to a fixed parameterization by the harmonic splines.     

Mesoscale Atmospheric Modeling of Extreme Velocities over the Sea of Okhotsk and Sakhalin

A detailed modeling of meteorological parameters over the last 30 years (1985–2014) has been performed for the Sea of Okhotsk and Sakhalin regions in the frame of the COSMO-CLM regional mesometeorological nonhydrostatic atmospheric model. The downscaling technology is suggested and achieved with three consequent “nesting domains” (with 13.2-, 6.6-, and 2.2-km grid scales). The COSMO-CLM model reproduces (especially successfully on the 2.2-km grid scale) the extremes of wind velocity observed by meteorological stations well. Synoptic situations accompanied by extreme wind speeds are reproduced in detail.     

北黄海大气颗粒态营养元素的季节分布特征

2006年7月～2007年10月对北黄海海域大气气溶胶及其负载的营养元素在春、夏、秋、冬4个季节的浓度分布进行了调查.结果显示,大气总悬浮颗粒物(TSP)、大气颗粒态总碳、钠、钙、镁、氮和磷都呈现出明显的季节变化,但是不同元素的季节分布规律不同.TSP、总碳和氮浓度都是春冬季较高,秋季次之,夏季最低.钠的季节变化与TSP不同,为夏季>冬季>春季>秋季,水溶性钙和镁分别呈现出春季>秋季>冬季>夏季及秋季>冬季>春季>夏季的季节变化.而水溶性磷酸盐浓度夏季最高,春季次之,秋冬季浓度很低.春、夏、秋、冬4季TSP、总碳和氮在不同采样海域的分布特征类似,即在离岸较近海域采集的样品TSP浓度较高,尤其是靠近辽东半岛和山东半岛海域.钠在不同采样海域的分布与TSP完全不同.各航次内钙、镁在不同采样海域的分布特征较复杂,呈现出与TSP和钠都不尽相同的分布特征.