• Journal of Environmental Science International
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• v.3 no.4
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• pp.305-315
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• 1994

The field observation was carried out to investigate the characteristics of surface inversion layer at Kimhae using the feild observed date and upper layer meteorological data during 4-5 February 1993. The results of the study can be summarized as follows : The maximum height of surface inversion layer observed at Kimhae is 193m and the height of upper level inversion layer ranges from 2nm to 300m. The surface weather elements was influenced the formation of surface inversion layer. According to the pasquill stability and time variation of temperature with height, both the surface heating from insolation and the disturbance of upper level of inversion layer was influenced the disappearance of inversion layer. And the stability of surface temperature inversion layer generally belongs to the class of F, that of upper level temperature inversion layer commonly to the class of E.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.195-202
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• 1998

The low level atmospheric obsewation carried out to Investigate magnitude, formation and dissipation of nocturnal surface Inversion layer, also to survey relation to each meterological parameter In Inversion layer at Pusan power plant for Oct. 13, 1996. As coastal area, the surface Inversion layer height was relatively high(186m), and after sunset unstable layer formated firom surface to around 40m, and the Inversion layer was left still in the upper layer. The surface Inversion layer dissipated at 0920LST perfectly. The layer that strong Inversion layer was formated, showed steep variation of potential temperature and wand speed and relative humidity.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.155-160
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• 2002

Using measured data at Daegu by tethersonde for the period of 1984∼1987, we have investigated the lower atmospheric boundary layer structure including relationships between inversion layer and meteorological factors(wind and temperature), and the inversion strength and inversion height. The inversion layer was defined from the vertical temperature profile and its strength was analyzed with the wind shear as well as the vertical temperature gradient. From October to January, measured inversion layer isn't destroyed, however, in June, after sun rise, it is destroyed by surface heating and mixed layer is developed from surface. According to Pasquill stability classes, the moderately stable cases dominated. It's the larger vertical temperature gradient the lower SBL height. We have introduced B(bulk turbulence scale) which indicated SBL height. It's larger B, the higher SBL height and vice versa. It was noted that the bulk turbulence scale (B) is appropriate to determine the stable boundary layer height.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.103-113
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• 1997

The research described in this paper was conducted to estimate the stability and heat budget in planetary boundary layer (PBL) at Kimhae. The upper air observation was carried out during period from 3 Februsry 1993 to 5 February 1993 at Kimhae. The surface observation data used the one during period from 1 April 1994 to 31 March 1995. The maximum height of inversion layer observed at Kimhae was 310 m. Destruction of the inversion was simultaneously occurred at the surface and the mid-layer (200 $\sim$ 300 m), however the origin of destruction is different each other. The surface inversion is destructed by surface heating owing to growing radiation in surface but disappearance of the mid-layer inversion is related to the upper cold air movement.

• Journal of Environmental Science International
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• v.5 no.4
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• pp.441-451
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• 1996

The surface meteorological and upper layer meteorological observation carried out to investigate influences of sea breeze effect on lower layer atmosphere at Gori nuclear power plant for 29∼30 July, 1996. According to surface meteorological data, the inflow of sea breeze was occurred 11:30 on 29 July, 10:30-on 30 July, respectively, at observation site. And the meteorological tower data showed that wind direction of sea breeze was identified as south-westerly, and wind speed of 58 m was 2 times stronger than that of 10 m. It is notworthy that surface inversion layer which built from the night time to daybreak of next day was not broken off by seab reeze's inflow for daytime, and strong inversion layer observed at 47∼243 m with moderately stable class (F) by URC. It was found that strong stable layer of potential temperature appeared at that layer, maximum relative humidity observed at the bottom of inversion layer and maximum mixing ratio observed in the low of inversion layer.

• Ocean and Polar Research
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• v.42 no.2
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• pp.97-113
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• 2020

In-situ observations were carried out in April 2015 to investigate the occurrence of water temperature inversion in a region west of Jeju Island. Analysis of in-situ in the western part of Jeju island showed that cold water moved to the southeast from the surface to the middle layer and warm water moved from the middle to the lower layer of the northwest direction. The water temperature inversion occurred at 84 stations (63.1%) out of 133 stations. At the boundary of the water temperature inversion layer, it was formed in the middle layer and disappeared. In the strongly appearing, it started from the middle layer to the lower layer. The shape of the water temperature inversion layer was different. As a result of horizontal water temperature slope analysis of the water temperature inversion zone, maximum 0.23℃/km was obtained and the mean was 0.06℃/km. The role of water temperature inversion as an indicator to determine the formation of water front. As a result of the water mass analysis, Jeju Warm Current Water and Tsushima Warm Current Water of high temperature and high salt intruded from the middle to the bottom. In the middle layer occurred as the Yellow Sea Cold Water of low water temperature and low salinity expanded.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.555-563
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• 2005

This study presents the characteristics of nocturnal inversion layer and their effect on the concentration variations of surface air pollutants using tethersonde and automatic weather station (AWS, 2 layer tower) system in Ulsan during 2003, The method for the distinction of inversion intensity was decided based on the sum of nocturnal temperature gradient. As the results, there was a close correlation (correlation coefficient of 0,76) between the maximum inversion height obtained from tethersonde and the sum of nocturnal temperature gradient. The air pollutant concentration was also directly proportional to the inversion intensity. When the inversion intensity was strong in the nighttime, ozone $(O_3)$ concentration was lower, while nitrogen dioxide $(NO_2)$ concentration was higher. The carbon monoxide (CO) concentration was gradually higher according to the nocturnal inversion intensity, whereas sulfur dioxide $(SO_2)$ concentration was relatively constant. In addition, we found that there was no correlation between the inversion intensity and TSP concentration.

• Membrane Journal
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• v.15 no.2
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• pp.85-104
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• 2005

Recently, membrane can be prepared by two methods, phase inversion and electrospinning techniques. Phase inversion technique is a conventional but commercially preparation membrane. The most versatile of preparation in this technique is immersion of the cast film into nonsolvent bath, causing dense top layer with a finger-like pattern in the sub layer membrane. The membrane pore size getting from phase inversion is in the range of micro or submicrometer. As a result, it can be used as microfiltration and ultrafiltration applications. A new technique, electrospinning, is introduced for membrane preparation. Nonwoven nanofibrous mat or nanofibrous membrane is obtained. In this technique, electrostatic charge is introduced to the solution jet, causing a thin fiber with high surface area; hence it can be used in the applications where high surface area-to-volume or length-to-diameter ratios are required. Moreover, the pore size can be controlled by controlling the time of electrospinning. Hence, it can be used as a filter for filtering microparticles as well as nanoparticles.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.244-254
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• 2018

Ulaanbaatar, the capital of Mongolia, is subject to high levels of atmospheric pollution during winter, which severely threatens the health of the population. By analyzing surface meteorological data, ground-based LIDAR data, and radiosonde data collected from 2008 to 2016, we studied seasonal variations in particulate matter (PM) concentration, visibility, relative humidity, temperature inversion layer thickness, and temperature inversion intensity. PM concentrations started to exceed the 24-h average standard ($50{\mu}g/m^3$) in mid-October and peaked from December to January. Visibility showed a significant negative correlation with PM concentration. Relative humidity was within the range of 60-80% when there were high PM concentrations. Both temperature inversion layer thickness and intensity reached maxima in January and showed similar seasonal variations with respect to PM concentration. The monthly average temperature inversion intensity showed a strong positive correlation with the monthly average $PM_{2.5}$ concentration. Furthermore, the temperature inversion layer thickness exceeded 500 m in midwinter and overlaid the weak mixed layer during daytime. Radiative cooling enhanced by the basin-like terrain led to a stable urban atmosphere, which strengthened particulate air pollution.

• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.557-564
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• 2011

This study was conducted to investigate the sudden rise of fine particle concentration after the passage of typhoon USAGI and NARI in Busan. Nocturnal inversion layer was formed at atmospheric boundary layer and wind direction changed from southerly wind to northeasterly wind after USAGI passed through Busan. Fine particle concentration in Busan rapidly increased by subsidence of air pollutants released from sources and dust transported from in the vicinity of industrial regions. Wind direction changed from northeasterly wind to southeasterly wind, wind velocity increased and lower atmosphere became extremely unstable after NARI passed through Busan. $PM_{10}$ concentration of Busan increased sharply because of surface dust dispersed by strong wind. Fine particle concentration generally decreases by precipitation and wind after typhoon passes through. However, the concentration can also go up not only by subsidence and transportation in nocturnal inversion layer but also by surface dust which temporarily occurs by strong wind.