scholarly journals Double Compressions of Atmospheric Depth by Geopotential Tendency, Vorticity, and Atmospheric Boundary Layer Affected Abrupt High Particulate Matter Concentrations at a Coastal City for a Yellow Dust Period in October

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Hyo Choi ◽  
Mi Sook Lee
Keyword(s):  
Boundary Layer ◽  
Inversion Layer ◽  
Ground Surface ◽  
Internal Boundary ◽  
Gobi Desert ◽  
Particulate Matters ◽  
Atmospheric Depth ◽  
Hysplit Model ◽  
On The Road ◽  
The City

Using GRIMM-aerosol sampler, NOAA-HYSPLIT model, and 3D-WRF-3.3 model, the transportation of dusts from Gobi Desert toward Gangneung city, Korea was investigated from 09:00 LST October 27 to 04:00 LST October 28, 2003. Maximum PM10 (PM2.5, PM1) concentration was detected with 3.8 (3.4, 14.1) times higher magnitude than one in non-Yellow Dust period. The combination of dusts transported from the desert under westerly wind with particulate matters and gases from vehicles on the road of the city caused high PM concentrations near the ground surface at 09:00 LST and their maxima at 17:00 LST near sunset with further pollutants from heating boilers in the resident area. Positive geopotential tendency at the 500 hPa level of the city (∂Φ/∂t; m day−1) corresponding to negative vorticity of-4×10-5 sec−1(-2.5×10-5 sec−1) at 0900 LST (21:00 LST; at night) was +83 m day−1(+30 m day−1) and it caused atmospheric depth between 500 hPa level and the ground surface to be vertically expanded. However, its net reduction to −53 m/12 hrs until 21:00 LST indicated synoptic-scale atmospheric layer to be vertical shrunken, resulting in the increase of PM concentrations at 17:00 LST. Simultaneously, much shallower microscale stable nocturnal surface inversion layer (NSIL) than daytime thermal internal boundary layer induced particulate matters to be merged inside the NSIL, resulting in maximum PM concentrations at 17:00 LST.

TO THE QUESTION OF THE IMPACT OF CLIMATE CHANGE ON THE ECOLOGICAL STATE OF ARTIFICIAL PLANTATIONS OF PITSUNDSKAYA PINE IN THE SEASIDE AREA OF GELENDZHIK

2017 ◽  
Author(s):  
Elizaveta Derevenets ◽  
Elizaveta Derevenets
Keyword(s):  
Negative Impact ◽  
Standard Technique ◽  
Negative Influence ◽  
Exhaust Gases ◽  
The Road ◽  
Industrial Enterprises ◽  
Federal Highway ◽  
On The Road ◽  
The Impact ◽  
The City

Gelendzhik is the resort town, there aren't a lot of industrial enterprises here. The main pollutant is transport. The work purpose is the assessment of a condition of the artificial landings of a pine located along the Federal highway "Don" and landings, which is nearly the sea coast. Researches were conducted to a standard technique of the General vital state (A. S. Bogolyubov). The assessment of a condition of pines was carried out during 6 years: from 2010 to 2015. For carrying out research we used 6 experimental grounds on the Markotkhsky spine and 2 control grounds within the town. We investigated 24 trees on each platform, middle age of the trees were 30 - 40 years. Results. 1. The condition of trees in the pine forests located in immediate proximity with the Federal highway "Don" (No. 1, 2, 3) is unsatisfactory. As even weak influences of the majority of atmospheric gaseous pollutants (sulphurous gas, nitrogen oxides, etc.) give effect of a necrosis and hloroz of pine needles, the condition of pines is connected with technogenic pollution. So near the Federal highway "Don" the air environment is strongly polluted by exhaust gases. Information of 2012 confirm that negative influence of the route on Markotkh's vegetation decreases at reduction of load of the route. 2. On the sites located above on a slope (No. 4,5,6) thanks to remoteness and the wind mode intensity of influence of pollutants is lower and a condition of pines the quite satisfactory. 3. Trees on the sites located near the sea (No. 7,8) are in a good shape. Small deterioration of a state is noted in very droughty years. Conclusion. Results of six years' research show that the condition of the plantings which are in close proximity with the road worsens. It is explained by increase in intensity of the movement on the road, especially during a resort season. Gelendzhik is the city with a good ecological shape, but the damage to environment is already caused. If not to take measures, we can lose a unique part of the nature in the future, recreate it will be impossible. Measures of reduction of negative impact of exhaust gases were offered. Results of researches are transferred to ecological department of the City administration of Gelendzhik.

TO THE QUESTION OF THE IMPACT OF CLIMATE CHANGE ON THE ECOLOGICAL STATE OF ARTIFICIAL PLANTATIONS OF PITSUNDSKAYA PINE IN THE SEASIDE AREA OF GELENDZHIK

2017 ◽  
Author(s):  
Elizaveta Derevenets ◽  
Elizaveta Derevenets
Keyword(s):  
Negative Impact ◽  
Standard Technique ◽  
Negative Influence ◽  
Exhaust Gases ◽  
The Road ◽  
Industrial Enterprises ◽  
Federal Highway ◽  
On The Road ◽  
The Impact ◽  
The City

Gelendzhik is the resort town, there aren't a lot of industrial enterprises here. The main pollutant is transport. The work purpose is the assessment of a condition of the artificial landings of a pine located along the Federal highway "Don" and landings, which is nearly the sea coast. Researches were conducted to a standard technique of the General vital state (A. S. Bogolyubov). The assessment of a condition of pines was carried out during 6 years: from 2010 to 2015. For carrying out research we used 6 experimental grounds on the Markotkhsky spine and 2 control grounds within the town. We investigated 24 trees on each platform, middle age of the trees were 30 - 40 years. Results. 1. The condition of trees in the pine forests located in immediate proximity with the Federal highway "Don" (No. 1, 2, 3) is unsatisfactory. As even weak influences of the majority of atmospheric gaseous pollutants (sulphurous gas, nitrogen oxides, etc.) give effect of a necrosis and hloroz of pine needles, the condition of pines is connected with technogenic pollution. So near the Federal highway "Don" the air environment is strongly polluted by exhaust gases. Information of 2012 confirm that negative influence of the route on Markotkh's vegetation decreases at reduction of load of the route. 2. On the sites located above on a slope (No. 4,5,6) thanks to remoteness and the wind mode intensity of influence of pollutants is lower and a condition of pines the quite satisfactory. 3. Trees on the sites located near the sea (No. 7,8) are in a good shape. Small deterioration of a state is noted in very droughty years. Conclusion. Results of six years' research show that the condition of the plantings which are in close proximity with the road worsens. It is explained by increase in intensity of the movement on the road, especially during a resort season. Gelendzhik is the city with a good ecological shape, but the damage to environment is already caused. If not to take measures, we can lose a unique part of the nature in the future, recreate it will be impossible. Measures of reduction of negative impact of exhaust gases were offered. Results of researches are transferred to ecological department of the City administration of Gelendzhik.

scholarly journals Ventilation of a Mid-Size City under Stable Boundary Layer Conditions: A Simulation Using the LES Model PALM

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 401
Author(s):  
Jonathan Biehl ◽  
Bastian Paas ◽  
Otto Klemm
Keyword(s):  
Boundary Layer ◽  
Stable Boundary Layer ◽  
Passive Scalar ◽  
City Center ◽  
Street Canyons ◽  
Stable Boundary ◽  
Northwest Germany ◽  
Stable Conditions ◽  
Les Model ◽  
The City

City centers have to cope with an increasing amount of air pollution. The supply of fresh air is crucial yet difficult to ensure, especially under stable conditions of the atmospheric boundary layer. This case study used the PArallelized Large eddy simulation (LES) Model PALM to investigate the wind field over an urban lake that had once been built as a designated fresh air corridor for the city center of Münster, northwest, Germany. The model initialization was performed using the main wind direction and stable boundary layer conditions as input. The initial wind and temperature profiles included a weak nocturnal low-level jet. By emitting a passive scalar at one point on top of a bridge, the dispersion of fresh air could be traced over the lake’s surface, within street canyons leading to the city center and within the urban boundary layer above. The concept of city ventilation was confirmed in principle, but the air took a direct route from the shore of the lake to the city center above a former river bed and its adjoining streets rather than through the street canyons. According to the dispersion of the passive scalar, half of the city center was supplied with fresh air originating from the lake. PALM proved to be a useful tool to study fresh air corridors under stable boundary layer conditions.

scholarly journals Extracting Road Traffic Volume in the City before and during covid-19 through Video Remote Sensing

2021 ◽  
Vol 13 (12) ◽  
pp. 2329
Author(s):  
Elżbieta Macioszek ◽  
Agata Kurek
Keyword(s):  
Travel Behavior ◽  
Traffic Management ◽  
Road Traffic ◽  
Traffic Volume ◽  
The Road ◽  
Traffic Characteristics ◽  
Annual Average Daily Traffic ◽  
On The Road ◽  
The Impact ◽  
The City

Continuous, automatic measurements of road traffic volume allow the obtaining of information on daily, weekly or seasonal fluctuations in road traffic volume. They are the basis for calculating the annual average daily traffic volume, obtaining information about the relevant traffic volume, or calculating indicators for converting traffic volume from short-term measurements to average daily traffic volume. The covid-19 pandemic has contributed to extensive social and economic anomalies worldwide. In addition to the health consequences, the impact on travel behavior on the transport network was also sudden, extensive, and unpredictable. Changes in the transport behavior resulted in different values of traffic volume on the road and street network than before. The article presents road traffic volume analysis in the city before and during the restrictions related to covid-19. Selected traffic characteristics were compared for 2019 and 2020. This analysis made it possible to characterize the daily, weekly and annual variability of traffic volume in 2019 and 2020. Moreover, the article attempts to estimate daily traffic patterns at particular stages of the pandemic. These types of patterns were also constructed for the weeks in 2019 corresponding to these stages of the pandemic. Daily traffic volume distributions in 2020 were compared with the corresponding ones in 2019. The obtained results may be useful in terms of planning operational and strategic activities in the field of traffic management in the city and management in subsequent stages of a pandemic or subsequent pandemics.

scholarly journals Nocturnal Boundary Layer Evolution and Its Impacts on the Vertical Distributions of Pollutant Particulate Matter

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 610
Author(s):  
Yu Shi ◽  
Lei Liu ◽  
Fei Hu ◽  
Guangqiang Fan ◽  
Juntao Huo
Keyword(s):  
Boundary Layer ◽  
Nitrate Concentration ◽  
Inversion Layer ◽  
Mixing Layer ◽  
Early Morning ◽  
Nocturnal Boundary Layer ◽  
Atmospheric Environment ◽  
Considerable Proportion ◽  
Surface Inversion ◽  
Vertical Distributions

To investigate the evolution of the nocturnal boundary layer (NBL) and its impacts on the vertical distributions of pollutant particulates, a combination of in situ observations from a large tethered balloon, remote sensing instruments (aerosol lidar and Doppler wind lidar) and an atmospheric environment-monitoring vehicle were utilized. The observation site was approximately 100 km southwest of Beijing, the capital of China. Results show that a considerable proportion of pollutant particulates were still suspended in the residual layer (RL) (e.g., the nitrate concentration reached 30 μg m−3) after sunset. The NBL height calculated by the aerosol lidar was closer to the top of the RL before midnight because of the pollutants stored aloft in the RL and the shallow surface inversion layer; after midnight, the NBL height was more consistent with the top of the surface inversion layer. As the convective mixing layer gradually became established after sunrise the following day, the pollutants stored in the nocturnal RL of the preceding night were entrained downward into the mixing layer. The early morning PM2.5 concentration near 700 m in the RL on 20 December decreased by 83% compared with the concentration at 13:34 on 20 December at the same height. The nitrate concentration also decreased significantly in the RL, and the mixing down of nitrate from the RL could contribute about 37% to the nitrate in the mixing layer. Turbulence activities still existed in the RL with the bulk Richardson number (Rb) below the threshold value. The corresponding increase in PM2.5 was likely to be correlated with the weak turbulence in the RL in the early morning.

Mitigation of road traffic crash hazard in Pakistan

2014 ◽  
Vol 23 (5) ◽  
pp. 567-585
Author(s):  
Muhammad Masood Rafi ◽  
Ashar Hashmat Lodi ◽  
Muhammad Arsalan Effendi
Keyword(s):  
Road Traffic ◽  
Evaluation Model ◽  
Road Traffic Crash ◽  
Potential Hazard ◽  
Suggested Model ◽  
Male Population ◽  
Content Type ◽  
The Road ◽  
On The Road ◽  
The City

Purpose – Road traffic crashes (RTCs) result in creating significant social and economic hazard for affectees, their families and society. The purpose of this paper is to present studies which were conducted to study the patterns of RTCs in Karachi which is a metropolitan city of Pakistan. The studies were conducted on one of the busiest roads in the city named as Shara-e-Faisal. The influence and contribution of different factors in RTCs has been studied and hazardous road sections of Shara-e-Faisal have been identified. Based on the data analysis, an evaluation model has been suggested to reduce the hazard of RTCs on Shara-e-Faisal. The objective of the presented studies is to increase the present level of safety of road travel by reducing crashes on Shara-e-Faisal. Design/methodology/approach – Existing data of RTCs in Karachi have been analysed for the presented studies. For this purpose, Shara-e-Faisal was divided in sections of 1 km length to study the vehicle crash pattern. Location surveys were conducted to record physical conditions of this road. A cluster analysis was carried out to identify hazardous sections of the road. An evaluation model has been suggested in the end to reduce the hazard of RTCs by identifying hazardous road sections of Shara-e-Faisal. Findings – The analysis of the data revealed that the crashes were higher over weekend and on Monday. Male population, particularly young people, and motorcycle riders were the largest affectees of RTCs. In general, more daytime crashes were recorded as compared to nighttime crashes. The crashes in the mid block of the road and those involving rear-end collisions were higher. The hazardous road locations were related to poor road conditions. Statistical analysis indicated that alternate routes were required to reduce the RTC hazard on Shara-e-Faisal. Research limitations/implications – The paper is a small, but an original, contribution to identify a potential hazard which is faced by the community in the city. This is the first attempt (to the best of authors’ knowledge) to address the issue of RTCs in Karachi from an engineering view point. Practical implications – The suggested model can be employed by the authorities as a guideline to mitigate the hazard of road crashes in the country. Originality/value – The paper provides valuable information on the road traffic incidents, their pattern and contributing factors in one of the largest metropolis of Pakistan. The suggested model can become helpful in reducing RTCs in Pakistan.

A study of wind speed modification and internal boundary-layer heights in a coastal region

1988 ◽  
Vol 42 (4) ◽  
pp. 313-335 ◽  
Author(s):  
Hans Bergström ◽  
Per-Erik Johansson ◽  
Ann-Sofi Smedman
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Coastal Region ◽  
Internal Boundary Layer ◽  
Internal Boundary

Art. VII.—An Account of Jerusalem, translated for the late Sir H. M. Elliot, from the Persian text of Náṣir ibn Khusrú's Safarnámah

1873 ◽  
Vol 6 (1) ◽  
pp. 142-164
Author(s):  
A. R. Fuller
Keyword(s):  
The Other ◽  
The Road ◽  
On The Road ◽  
The Hill ◽  
The City

On the 3rd of Ramazán, I left Ramlah, and went to a village called Khátún, and from thence to another, which they styled Kariatu-l-'Anab (Grape hamlet). On the road I observed plenty of wild rue growing spontaneously on hill and dale. I also noticed at this village a very delightful spring of water gushing out of a rock, where they had constructed reservoirs, and built edifices. From thence I proceeded up some rising ground, under the impression that I was ascending a hill, and that on going down the other side the city would lie before me. After I had climbed the ascent however for a short way, a vast wilderness lay in my front, partly stony, and partly showing merely the bare earth. At the summit of the hill stands the city of the “Baitu-l-Mukaddas” (Sacred Tabernacle, i.e. Jerusalem), between which and Tarábulis, whichis on the coast, are 56 parasangs, and from Balkh to Jerusalem 876.

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