Study of sea waves under the action of deep cyclones

Data from full-scale observations of the coastal zone during the passage of deep cyclones are analyzed. The time interval when three deep cyclones acted in the region of observations was chosen. The generation of long-wave processes during cyclones with different meteorological parameters and at different directions of approaching the shore was of interest. Data from the Management of Hydrometeorological Service were invoked for compiling maps of weather conditions, and meteorological data obtained from digital meteorological stations, as well as the spectral characteristics of oscillations of the hydrostatic pressure level at observational points, were analyzed. The frequencies of excitation of long-wave oscillations caused by cyclones were determined. Particular attention was paid to the range of periods of swell and wind waves. It was detected that swell waves are excited during the approach of cyclones at uncharacteristic frequencies with their subsequent displacement into their own frequency range.     

Dynamics of trace gases and aerosols in the atmosphere with consideration for heterogeneous processes

A combined mathematical model has been developed to reproduce space and time variations in the concentrations of multicomponent gas constituents and aerosols in the atmosphere on both regional and urban scales. This model contains blocks of transport of gas constituents and aerosols in the atmosphere with consideration for homogeneous binary nucleation, the kinetic processes of condensation/evaporation and coagulation, chemical processes occurring in both gas and liquid phases, and the processes of mass exchange during the gas-droplet (particle) interaction. A nonhydrostatic model of atmospheric mesoscale processes is used to calculate the fields of meteorological elements and turbulent characteristics. The generation of new-phase particles from precursor gases by the mechanism of homogeneous binary nucleation and their interaction with background aerosol are considered. The results of numerical experiments are compared with the data obtained from field observations of both space and time variations in the concentrations of gas constituents and aerosols and in the ionic content of aerosol particles over the Baikal region under the influence of emissions from powerful industrial sources.     

Atmospheric Internal Gravity Waves Caused by Tsunamis over Kuril Islands

MODIS (Aqua and Terra) space images of the northwest part of the Pacific Ocean at instants of considerable tsunamis in 2009–2011 have been analyzed. Periodic cloud structures typical for internal gravity waves (IGWs) in the atmosphere have been revealed in the region of the Kuril Islands in five cases. It has been shown that the meteorological conditions observed during those events favored the appearance of such phenomena. The continuous oceanic upwelling in the region of the Kuril–Kamchatka Trench is a favorable factor for IGW generation due to the creation of temperature contrasts observed both in warm and cold seasons between the ground layer of the atmosphere and ocean surface. The estimate of the structure of cloud manifestations of atmospheric waves by satellite images testifies also to the influence of the Kuril Ridge orography on their appearance and propagation over the water area under study. The increase in amplitudes and duration of oscillations caused by the tsunami in the shelf zone can be an auxiliary factor for the IGW generation over coastal territories.     

Studies of hydrophysical processes during monitoring of the anthropogenic impact on coastal basins using the example of Mamala Bay of Oahu Island in Hawaii

This paper presents the main results of processing the data obtained in the study of hydrophysical processes during multidisciplinary monitoring of the anthropogenic impact on the coastal basin of Mamala Bay (Oahu Island, Hawaii). The results of the hydrophysical measurements carried out in August–September of 2002–2004 using stationary moorings and dropped and towed ship sensors were analyzed as the initial data. On the basis of these measurements, spatiotemporal, statistical, and spectral characteristics of different hydrophysical parameters of the marine envrionement in the basin of Mamala Bay were calculated, including three-dimensional components of the velocity vectors, the spectra of different components of velocities, the spectra of temperature fluctuations, and the characteristics of internal waves. The variability of the temperature fields and the correlation of the tidal phenomena with the temperature measurements and fluctuations caused by internal waves were analyzed. The materials and methods of the oceanographic studies and the results of the analysis of the meteorological and hydrological conditions are presented. The results obtained are used for a multidisciplinary analysis of the satellite and sea truth data.     

Influence of internal gravity waves on meteorological fields and gas constituents near Moscow and Beijing

The influence of internal gravity waves on the spatial coherence and temporal variability of the atmospheric pressure, wind velocity, and gas constituents near Moscow and Beijing is studied in the mesoscale range of periods: from a few tens of seconds to several hours. The results of simultaneous measurements of variations in the atmospheric pressure (using a network of spaced microbarographs), wind velocity at different heights of the atmospheric boundary layer, and gas constituents are given for each city. The wave structures are filtered using a coherence analysis of the atmospheric pressure variations at different measurement sites. The dominant periods and the coherences, phase speeds, and horizontal scales of variations corresponding to these periods are estimated. The general mechanism of the influence of wave structures on meteorological fields and gas constituents is discussed, which is independent of the measurement site and the specificity of meteorological conditions.     

Dependence of cerebral-cortex activation in women on environmental factors

The investigation of female physiological reactions to different meteorological conditions and space weather is relevant, since there are little experimental findings in this field. The purpose of this work is to determine how the level of cerebral-cortex activity in women depends on the meteorological and cosmophysical parameters of weather and space processes. We studied electroencephalograms (EEGs) recorded at rest in the sitting position and with eyes closed. We performed four series of measurements of brain bioelectrical activity from February to June 2013. We found that the level of cortical activity recorded by EEG changed significantly during these 6 months. Significant differences were detected between the cortical activity and the parameters of weather and space processes; namely, an increase in the air temperature and a decrease in the wind speed and cosmic-ray energy result in a decrease in the activity rate of the right occipital lobe.     

利用水文、气象要素因子的变化趋势预测南海区赤潮的发生

有些文献指出:“赤潮发生起因因种而异,但大体上气候气象条件诸如温度、风力、风向,季风转换、气压等;海况、潮汐、流等以及海水的理化特征,如盐度、营养元素等,这些皆会成为某种赤潮爆发的因子或诱导因素[1]”。根据赤潮监控区监测资料分析:在南海赤潮多发区,海水富营养化条件已经具备,因此气象、水文要素条件就成为赤潮爆发的重要启动因子,而天气环流的维持与变化决定了气象、水文要素因子的稳定与变化,再根据赤潮生物培养试验,从初期繁殖到后期的爆发性繁殖,直至达到赤潮生物密度,这一过程一般都需要4~5d的时间。针对这一现象,通过对近10a的赤潮发生个例进行统计分析,统计其生成前期的天气环流形势和水文气象要素,分析出赤潮生成前期的环流模式和筛选出诱发赤潮爆发的重要因子,并依此来作为预报赤潮生成的方法,依照此方法对2003年的赤潮进行预报,其效果是另人满意的。     

Elevation trends and shrink–swell response of wetland soils to flooding and drying

Given the potential for a projected acceleration in sea-level rise to impact wetland sustainability over the next century, a better understanding is needed of climate-related drivers that influence the processes controlling wetland elevation. Changes in local hydrology and groundwater conditions can cause short-term perturbations to marsh elevation trends through shrink–swell of marsh soils. To better understand the magnitude of these perturbations and their impacts on marsh elevation trends, we measured vertical accretion and elevation dynamics in microtidal marshes in Texas and Louisiana during and after the extreme drought conditions that existed there from 1998 to 2000. In a Louisiana marsh, elevation was controlled by subsurface hydrologic fluxes occurring below the root zone but above the 4 m depth (i.e., the base of the surface elevation table benchmark) that were related to regional drought and local meteorological conditions, with marsh elevation tracking water level variations closely. In Texas, a rapid decline in marsh elevation was related to severe drought conditions, which lowered local groundwater levels. Unfragmented marshes experienced smaller water level drawdowns and more rapid marsh elevation recovery than fragmented marshes. It appears that extended drawdowns lead to increased substrate consolidation making it less resilient to respond to future favorable conditions. Overall, changes in water storage lead to rapid and large short-term impacts on marsh elevation that are as much as five times greater than the long-term elevation trend, indicating the importance of long-term, high-resolution elevation data sets to understand the prolonged effects of water deficits on marsh elevation change.     

影响我国近海航海的水文气象要素气候分析

本文分析了影响航海活动的我国沿海水文气象要素风、浪、能见度、台风的时空分布及以这些要素为指标所作的近海航海气候区划。得到了我国沿海不同海区航海条件的特征和近海各个航海气候区航海条件的差异及对其的评价，这些结果对近海航海活动很有意义。     

石家庄地区输电线路雷击事故发生的气象条件

为了研究石家庄地区输电线路雷击事故发生的气象条件,利用该地区1990—2018年输电线路雷击事故发生的详细资料和地面、探空气象资料,分析了输电线路雷击事故的时空变化,确定了容易发生输电线路雷击事故的天气系统配置和探空物理量阈值;通过输电线路雷击事故发生的气象条件,检验了2019—2020年输电线路雷击事故预报的准确性。结果表明:石家庄输电线路雷击事故主要发生在夏季傍晚前到前半夜,夏季发生概率明显高于春、秋季;输电线路雷击事故发生日数自西向东逐渐减少,集中发生在西部山区的井陉,其次是市区,井陉发生概率远高于其他地区;对流天气影响系统主要为高空槽型和冷涡型,探空物理量同时满足首要条件和附加条件时,引发输电线路雷击事故概率较高;输电线路雷击事故发生的气象条件在2019—2020年得到较好的预测检验,对防范雷击事故有一定指导意义。     

The seasonal closure of tidal inlets: Wilson Inlet—a case study

The seasonal closure of tidal inlets is a common and important coastal phenomena. However, studies which have been specifically geared to identify processes governing seasonal inlet closure are almost non-existent. Hence, this study was undertaken to gain insight into processes governing seasonal inlet closure. To determine the processes governing this phenomenon, Wilson Inlet, Western Australia, a typical seasonally open tidal inlet is taken as a case study. The study comprised of a field experiment over the summer of 1995, and a numerical modeling exercise employing a morphodynamic model. Results of the field study imply that longshore processes may not be the cause of inlet closure, but that onshore sediment transport due to persistent swell wave conditions in summer may govern seasonal closure of the inlet. Application of a morphodynamic model, which includes both cross-shore and longshore processes, to Wilson Inlet conclusively shows that seasonal closure of the inlet is due to onshore sediment transport under typical summer conditions. The effects of summer streamflow and storm events, which are not uncommon, are also examined using the morphodynamic model. The effect of both streamflow and storm events on the `open duration' of the inlet is shown to be dependent on the intensity and timing of the event.     

The concept of “representative tides” in morphodynamic numerical modelling

Process-based numerical modelling of coastal morphodynamics involves model and data reduction schemes in order to cope with computational limitations. Model reduction, on the one hand, may involve the discretisation of an interactive multidimensional, diverse natural system into a reduced set of coupled process-simulation modules. Data reduction schemes, on the other hand, are used to parameterise processes. The use of schematised open-boundary conditions, which are considered as representative in terms of their cumulative morphological effect, is based on the concept of “morphological” or “representative” boundary conditions. Recent model applications show realistic tendencies in terms of depositional and erosional areas. By contrast, the reproduction of characteristic changes in morphology such as the migration of bars, banks and channels is only occasionally achieved. Using field data on observed morphological impact of a single storm event and numerical model data, it is demonstrated that the concept of representative tides may lead to simulations of morphological development lacking natural dynamics. It is proposed that rather than being based on “representative” single tides, morphodynamic models should be applied with open-boundary conditions which take variations in longer-term tidal and meteorological forcing into account.     

利用水文气象要素因子的变化趋势预测南海区赤潮的发生

有关文献指出:“赤潮发生起因因种而异……,但大体上气候气象条件诸如温度、风力、风向,季风转换、气-压等;海况、潮汐、流等以及海水的理化特征,如盐度、营养元素等,这些皆会成为某种赤潮爆发的因子或诱导因素”。根据赤潮监控区监测资料分析: 在南海赤潮多发区,海水富营养化条件已经具备,因此气象、水文要素条件就成为赤潮爆发的重要启动因子,而大气环流的维持与变化决定了气象、水文要素因子的稳定与变化,然而根据赤潮生物培养试验,从初期繁殖到后期的爆发性繁殖,直至达到赤潮生物密度,这一过程一般都需要4-5d的时间。针对这一现象,通过对近10a的赤潮发生个例进行统计分析,统计其生成前期的大气环流形势和水文气象要素,分析出赤潮生成前期的环流模式和筛选出诱发赤潮爆发的重要因子,并以此来作为预报赤潮生成的方法。依照此方法对2003年的赤潮进行预报,其效果是令人满意的。     

2006年南极长城站的气象要素特征

利用第22次南极长城站越冬气象考察所获取的常规气象观测资料,着重分析了2006年长城站的气压、气温、地温、降水、湿度、风等气象要素和天气现象的特征,并同1985～2005年的多年统计值进行了对比。所作分析有助于了解和研究南极长城站地区的气候特点。     

Novaya Zemlya bora and polar cyclones in spaceborne SAR and optical imagery

Izvestiya, Atmospheric and Oceanic Physics - Mesoscale meteorological phenomena, such as Novaya Zemlya bora and polar cyclones, have been studied based on the respective signatures in synthetic...     

Experimental study of the Rhone plume. Part I: physics and dynamics

The complicated dynamic processes occurring when fluvial waters mix with marine waters control the nature and the fluxes of materials exported by rivers to the sea. Understanding these processes is of primary importance in evaluating budgets. In wide-open estuarine situations these processes take place under the influence of an intense turbulence induced by tides. Conversely, the Rhone waters spread into the Mediterranean Sea in the form of an easily distinguishable buoyant plume often extending far offshore from the mouth of the river. The aim of this study is to describe the dynamic and hydrological fields on the basis of eulerian VHF radar mapping of surface currents coupled with lagrangian in situ physical or geochemical measurements. This paper focuses mainly on physical processes. Data analysis provides an insight into the typical scales of variability of the phenomena, either vertically or horizontally. It is shown that morphological fluctuations can occur (mainly in orientation and offshore extent) according to wind and outflow forcing conditions, and that the vertical structure variations can range from an almost unaltered two-layer distribution to an evolving and deepening mixed layer situation, or even to a more complex superimposed multi-layered structure. The simultaneous examination of radar maps and lagrangian drifter tracking allows the main dynamic tendencies of the Rhone plume to be sketched out.     

The role of cosmic and ionospheric disturbances in global climatic changes and pipeline corrosion

Physical causes controlling the influence of the main cosmic factors on the state of the ionosphere and, further, on weather and climatic phenomena, including the global warming, are investigated. These investigations are based on the Rydberg excitation of the experimentally observed microwave radiation of the Earth’s ionosphere by energetic ionospheric electrons. This microwave radiation virtually freely penetrates into the lower atmosphere, providing channels for the influence of solar variability on terrestrial phenomena. The factors causing an anomalous wear of Russian pipeline systems are also analyzed, and the methods for reducing their rapid corrosion through taking into account the influence of heliogeomagnetic and ionospheric disturbances are described. Such investigations are supported by the space experiment on permanent monitoring of the factors controlling heliogeomagnetic activity, i.e., fluxes of ionizing radiation of the Sun and fluxes of electrons precipitating from the radiation belts.     

Temporal variations in carbon dioxide and methane concentrations under urban conditions

Temporal variations in the surface concentrations of two greenhouse gases (carbon dioxide and methane) in the atmosphere over a large city are studied on the basis of the data obtained during the 2003–2005 observations at a Moscow station for environmental monitoring. This station is based on the TROICA mobile observatory and located at the meteorological station of the Faculty of Geography, Moscow State University, on Vorob’evy gory. The methods of isolating the background concentrations of greenhouse gases under urban conditions are proposed, and the excess concentrations of CO₂ and CH₄ over their background values are estimated for different seasons and times of day. The CO₂ and CH₄ concentrations are shown to have more pronounced diurnal cycles in summer than in winter. The main causes of temporal variations in the surface concentrations of CO₂ and CH₄ under urban conditions and the differences between the mean concentrations of these greenhouse gases in Moscow and other areas of Russia are analyzed. It is shown that variations in the surface concentrations of carbon dioxide and methane on different time scales are caused by different atmospheric processes (global circulation, mesoscale gravity waves, surface temperature inversions, etc.)     

海沧开发区工业废气对厦门市区大气影响的可能性

本文利用厦门的气象资料,从厦门地区的风况、大气稳定度和逆温层的分析,讨论了海沧开发区工业废气影响厦门市区的大气环境的可能性。     

Thermal structure and energy budget in a small high mountain lake: La Caldera,Sierra Nevada,Spain

This work examines the diel change of energy storage and its associated patterns of thermal stratification during the ice‐free period in a high mountain lake (La Caldera Lake, Sierra Nevada, Spain), in response to meteorological conditions. Bihourly data have been implemented to a standard methodology of surface heat exchange calculations in lakes. Strong variations have been observed on the diverse components of the energy budget at different time scales, ranging from diel to seasonal. Additionally, time‐series analyses have been applied to reveal the underlying periodicities involved in relation to the different variables studied. The results obtained from this study provided realistic conditions for the environmental modelling of such processes, which are very sensitive in time scale.