scholarly journals The Micrometeorology of the Haifa Bay Area and Mount Carmel during the Summer

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 354
Author(s):  
Ziv Klausner ◽  
Mattya Ben-Efraim ◽  
Yehuda Arav ◽  
Eran Tas ◽  
Eyal Fattal
Keyword(s):  
Atmospheric Transport ◽  
Similarity Theory ◽  
Anthropogenic Pollution ◽  
Temporal Analysis ◽  
Dispersion Modelling ◽  
Statistical Parameters ◽  
Night Time ◽  
Adverse Health Effects ◽  
Bay Area ◽  
Hourly Distribution

The Haifa bay area (HBA), which includes Mount Carmel and the Zevulun valley is the third largest metropolitan area in Israel. It is also a centre of heavy industry and an important transportation hub which serve as sources of local anthropogenic pollution. Such sources are associated with adverse health effects. In order to estimate the possible exposure of the inhabitants in such heterogeneous orographic area, a detailed atmospheric transport and dispersion modelling study is required, which in turn must take into account the local micrometeorology. The aim of this study is to conduct a spatio-temporal analysis of the flow field in the HBA in order to identify the common patterns of the average wind and characterize the statistical parameters of turbulence in this area, essential for detailed pollutants dispersion modelling. This study analyses data collected during four months of summer in a network of 16 weather stations which extend across Mount Carmel and the Zevulun valley. It was found that, during the evening and night time on Mount Carmel, different flow patterns may develop on each side, separated by the watershed line. When such conditions do not develop, as well as during the daytime, the wind field, both on Mount Carmel and the Zevulun valley is approximately homogenous. The analysis of the Monin–Obukhov similarity theory functions for the velocity standard deviations show a distinct difference between Mount Carmel and the Zevulun valley, as well as between strong and weak winds. This difference can be clearly seen also in the diurnal hourly distribution of atmospheric stabilities which exhibit higher proportions of unstable conditions in the Zevulun valley during day time and higher proportion of stable stratifications at the Mount Carmel during night-time.

The Canadian Meteorological Centre's Atmospheric Transport and Dispersion Modelling Suite

2015 ◽  
Vol 53 (2) ◽  
pp. 176-199 ◽  
Author(s):  
Réal D'Amours ◽  
Alain Malo ◽  
Thomas Flesch ◽  
John Wilson ◽  
Jean-Philippe Gauthier ◽  
...  
Keyword(s):  
Atmospheric Transport ◽  
Dispersion Modelling

scholarly journals Estimates of boundary layer parameters in the atmospheres of the terrestrial planets

1971 ◽  
Vol 40 ◽  
pp. 297-303
Author(s):  
G. S. Golitsyn
Keyword(s):  
Boundary Layers ◽  
Wind Velocity ◽  
Lower Layer ◽  
Similarity Theory ◽  
Potential Temperature ◽  
Terrestrial Planets ◽  
Turbulent Heat ◽  
Low Density ◽  
Free Atmosphere ◽  
Night Time

The similarity theory of atmospheric boundary layers is applied to an estimate of the form of vertical profiles of average wind velocity and potential temperature in the atmospheres of the terrestrial planets in day- and night-time conditions.It is then considered, as in the case of the earth, that the magnitude of the turbulent heat flux qT during the day is about 0.1 of q(1 – A), where q is the solar constant for the planet and A is its albedo; at night, qT is several times smaller still. The friction velocity u* is taken equal to 2–5% (depending upon the stratification) of the mean wind velocity in the free atmosphere, which was adopted from previous calculations (Golitsyn, 1968).The boundary layers in the atmospheres of Mars and Venus and in the hypothetical atmosphere of Mercury are examined in detail. Sharp temperature drops are characteristic of Mars within a few tens of meters from the surface, attaining a magnitude of several tens of degrees, especially during the day. Large changes of the wind velocity also take place in this thin lower layer. This effect results from the low density of the Martian atmosphere.For Venus, owing to the very high density of the atmosphere, the stratification is close to neutral, i.e., the temperature profile is close to the adiabatic one and the wind profile is of a logarithmic shape.Owing to high winds, the stratification on Mercury must also be close to neutral with respect to the wind (the profile being close to the logarithmic), but because of the expected low density, the temperature changes near the ground may still be very great.

scholarly journals Importance of Using Observations of Mixing Depths in order to Avoid Large Prediction Errors by a Transport and Dispersion Model

2009 ◽  
Vol 26 (1) ◽  
pp. 22-32 ◽  
Author(s):  
J. M. White ◽  
J. F. Bowers ◽  
S. R. Hanna ◽  
J. K. Lundquist
Keyword(s):  
Boundary Layer ◽  
Atmospheric Transport ◽  
Similarity Theory ◽  
Dispersion Model ◽  
Heat Fluxes ◽  
Synoptic Situation ◽  
Prediction Errors ◽  
Sensible Heat ◽  
Mixing Depth ◽  
Near Surface

Abstract The mixing depth of the boundary layer is an input to most atmospheric transport and dispersion (ATD) models, which obtain mixing depths in one of four ways: 1) observations by radiosondes, sodars, or other devices; 2) simulations by regional or mesoscale meteorological models; 3) parameterizations based on boundary layer similarity theory; or 4) climatological averages. This paper describes a situation during a field experiment when exceptionally low mixing depths persisted in the morning and led to relatively high observed tracer concentrations. The low mixing depths were caused by synoptic effects associated with a nearby stationary front and the outflow from a mesoscale thunderstorm complex located 20–50 km away. For the same time period, the ATD model-parameterized mixing depth was a factor of 5–10 higher, leading to predicted concentrations that were less than the observations by a factor of 5–10. The synoptic situation is described and local radiosonde and radar observations of mixing depth are presented, including comparisons with other more typical days. Time series of local observations of near-surface sensible heat fluxes are also plotted to demonstrate the suppression of turbulence by negative sensible heat fluxes during the period in question.

scholarly journals Diurnal variations of total carbon, dicarboxylic acids, ketoacids and α-dicarbonyls in aerosols in the northern vicinity of Beijing

2013 ◽  
Vol 13 (6) ◽  
pp. 16699-16731 ◽  
Author(s):  
N. He ◽  
K. Kawamura ◽  
K. Okuzawa ◽  
Y. Kanaya ◽  
Z. F. Wang
Keyword(s):  
Atmospheric Transport ◽  
Glyoxylic Acid ◽  
Dicarboxylic Acids ◽  
Abundant Species ◽  
Photochemical Oxidation ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Marine Aerosols ◽  
Night Time ◽  
Aerosol Mass

Abstract. Aerosol samples (TSP, n=58) were collected on day- and night-time basis at Mangshan in the north of Beijing, China in autumn 2007 to better understand the status of air quality and the influence of urban pollutants in the northern vicinity of Beijing. The samples were analyzed for aerosol mass, total carbon (TC), low molecular weight α, ω-dicarboxylic acids (C2-C12), ketoacids (ωC2-ωC9, pyruvic acid), α-dicarbonyls (glyoxal and methylglyoxal), as well as aromatic (phthalic, iso- and tere-phthalic) diacids. Aerosol mass and TC concentrations are higher in daytime than in nighttime. TC/aerosol mass ratios in this study are lower than those reported in megacities in East Asia, but higher than those reported in marine aerosols. Molecular distributions of diacids demonstrated that oxalic (C2) acid was the most abundant species, comprising 38–77% of total diacids, followed by succinic (C4) and malonic (C3) acids. For most compounds, the concentrations were higher in daytime than nighttime, indicating that diacids are produced in daytime by photochemical oxidation of organic precursors emitted from anthropogenic sources in Beijing during the transport to Mangshan area by the northward wind. However, we found that C2 concentrations are higher in nighttime than in daytime. A positive correlation of C2 to glyoxylic acid (ωC2) was obtained at night when relative humidity increased up to 100%, suggesting that aqueous phase production of C2 occurs in nighttime via the oxidation of ωC2. Depletion of C2 by photolysis of Fe-oxalato complexes might be another reason for the lower concentrations of C2 in daytime samples. High phthalic acid/C4 ratios in the aerosol samples suggest that automobile combustion and coal burning products are important sources, which are subjected to photochemical oxidation during the atmospheric transport of urban aerosols from Beijing. In contrast, higher concentrations of methylglyoxal in nighttime than daytime may suggest that isoprene emitted from the northern forest area is oxidized in daytime and then transported to the sampling area at night by northerly winds. This study demonstrates that secondary organic aerosols are significantly produced and aged in the vicinity of Beijing during atmospheric transport.

scholarly journals Comparison of measured residential black carbon levels outdoors and indoors with fixed-site monitoring data and with dispersion modelling

2020 ◽  
Author(s):  
Olena Gruzieva ◽  
Antonios Georgelis ◽  
Niklas Andersson ◽  
Tom Bellander ◽  
Christer Johansson ◽  
...  
Keyword(s):  
Time Series ◽  
Black Carbon ◽  
Health Effects ◽  
Dispersion Model ◽  
Monitoring Data ◽  
Dispersion Modelling ◽  
Night Time ◽  
Urban Background ◽  
Site Monitoring

AbstractEpidemiologic studies on health effects of air pollution usually rely on time-series of ambient monitoring data or on spatially modelled levels. Little is known how well these estimate residential outdoor and indoor levels. We investigated the agreement of measured residential black carbon (BC) levels outdoors and indoors with fixed-site monitoring data and with levels calculated using a Gaussian dispersion model. One-week residential outdoor and indoor BC measurements were conducted for 15 families living in central Stockholm. Time-series from urban background and street-level monitors were compared to these measurements. The observed weekly concentrations were also standardized to reflect annual averages, using urban background levels, and compared spatially to long-term levels as estimated by dispersion modelling. Weekly average outdoor BC level was 472 ng/m3 (range 261–797 ng/m3). The corresponding fixed-site urban background and street levels were 313 and 1039 ng/m3, respectively. Urban background variation explained 50% of the temporal variation in residential outdoor levels averaged over 24 h. Modelled residential long-term outdoor levels were on average comparable with the standardized measured home outdoor levels, and explained 49% of the spatial variability. The median indoor/outdoor ratio across all addresses was 0.79, with no difference between day and night time. Common exposure estimation approaches in the epidemiology of health effects related to BC displayed high validity for residencies in central Stockholm. Urban background monitored levels explained half of the outdoor day-to-day variability at residential addresses. Long-term dispersion modelling explained half of the spatial differences in outdoor levels. Indoor BC concentrations tended to be somewhat lower than outdoor levels.

scholarly journals Methodology for prediction and estimation of consequences of possible atmospheric releases of hazardous matter: "Kursk" submarine study

2003 ◽  
Vol 3 (3) ◽  
pp. 747-762 ◽  
Author(s):  
A. Baklanov ◽  
A. Mahura ◽  
J. H. Sørensen
Keyword(s):  
Atmospheric Transport ◽  
Dispersion Modelling ◽  
Human Errors ◽  
Risk Levels ◽  
Geographical Regions ◽  
Atmospheric Releases ◽  
Fast Transport ◽  
Transport Patterns ◽  
Integral Concentration

Abstract. There are objects with some periods of higher than normal levels of risk of accidental atmospheric releases (nuclear, chemical, biological, etc.). Such accidents or events may occur due to natural hazards, human errors, terror acts, and during transportation of waste or various operations at high risk. A methodology for risk assessment is suggested and it includes two approaches: 1) probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2) forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach could be applied during the preparation stage, and the second - during the operation stage. The suggested methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning) of the ``Kursk" nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137Cs) showed that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allowed to identify the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, the forecasts of possible consequences during phases of the high and medium potential risk levels based on a unit hypothetical release (e.g. 1 Bq) are performed. The analysis showed that the possible deposition fractions of 10-11 (Bq/m2) over the Kola Peninsula, and 10-12 - 10-13 (Bq/m2) for the remote areas of the Scandinavia and Northwest Russia could be observed. The suggested methodology may be used successfully for any potentially dangerous object involving risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature.

scholarly journals Analysis of air mass back trajectories with present and historical volcanic activity and anthropogenic compounds to infer pollution sources in the South Shetland Islands (Antarctica)

2018 ◽  
Vol 15 (1) ◽  
pp. 111-137 ◽  
Author(s):  
Danuta Szumińska ◽  
Sebastian Czapiewski ◽  
Małgorzata Szopińska ◽  
Żaneta Polkowska
Keyword(s):  
South America ◽  
Atmospheric Transport ◽  
Anthropogenic Pollution ◽  
South Shetland Islands ◽  
Eastern Coast ◽  
The South ◽  
Hysplit Model ◽  
Air Mass ◽  
Back Trajectories ◽  
Shetland Islands

Abstract This work analyses atmospheric transport of natural and anthropogenic pollution to the South Shetland Islands (SSI), with particular reference to the period September 2015 – August 2017. Based on data from the Global Volcanism Program database and air mass back trajectories calculated using the HySPLIT model, it was found that it is possible that in the analysed period volcanic pollution was supplied via long-range transport from South America, and from the South Sandwich Islands. Air masses flowed in over the South Shetland Islands from the South America region relatively frequently – 226 times during the study period, which suggests the additional possibility of anthropogenic pollution being supplied by this means. In certain cases the trajectories also indicated the possibility of atmospheric transport from the New Zealand region, and even from the south-eastern coast of Australia. The analysis of the obtained results is compared against the background of research by other authors. This is done to indicate that research into the origin of chemical compounds in the Antarctic environment should take into account the possible influx of pollutants from remote areas during the sampling period, as well as the possible reemission of compounds accumulated in snow and ice.

scholarly journals Contaminant Emissions As Indicators of Chemical Elements in The Snow Along a Latitudinal Gradient in Southern Andes

2020 ◽  
Author(s):  
Jaime Pizarro ◽  
Pablo Vergara ◽  
Sergio Cerda ◽  
Raul Cordero ◽  
Ximena Castillo ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atmospheric Transport ◽  
Chemical Elements ◽  
Spatial Scales ◽  
Anthropogenic Pollution ◽  
Air Contaminants ◽  
Latitudinal Transect ◽  
Volatile Organic ◽  
Particulate Contaminants

Abstract The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 mm and 10 mm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.

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