This study investigates the concentration sudden rise in fine particle according to resuspended dust from paved roads after sudden heavy rain in Busan on August 25, 2015. The localized torrential rainfall in Busan area occurred as tropical airmass flow from the south and polar airmass flow from north merged. Orographic effect of Mt. Geumjeong enforced rainfall and it amounted to maximum 80 ㎜/hr at Dongrae and Geumjeong region in Busan. This heavy rain induced flood and landslide in Busan and the nearby areas. The sudden heavy rain moved soil and gravel from mountainous region, which deposited on paved roads and near roadside. These matters on road suspended by an automobile transit, and increased fine particle concentration of air. In addition outdoor fine particle of high concentration flowed in indoor by shoes, cloths and air circulation.

The study investigates the characteristics of PM10 concentration in Guducsan air quality observatory and in particular, analyzes the relationship between sudden increase of PM10 concentration in the morning of spring 2014 and meteorological parameters. PM10 concentration in April was 46.9 ㎍/㎥, the highest, followed by 45.5 ㎍/㎥ and 44.6 ㎍/㎥ in March and May, and 21.9 ㎍/㎥ in August. The low concentration in the early morning appeared on 0800 LST in spring, summer, and fall, whereas it emerged on 0900 LST in winter. High concentration in daytime lasted from 1200 LST to 1500 LST in spring and fall, whereas it continued from 1300 LST to 1600 LST in winter. The findings of PM10 concentration and change of meteorological parameters in Guducsan from April 20th to 27th in 2014 are as follows. The low concentration at dawn and in the morning decreased due to strong land breeze. Also, the sudden increase of PM10 concentration in the morning was attributable to low wind speed. Lastly, the sudden decrease of PM10 concentration in the afternoon was attributed to diffusion by strong sea breeze.

This study investigates weekday/weekend characteristics of PM10 concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO4 2- to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. [NO3 -/SO4 2-] ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and Cl-/Na+ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

This study investigates weekday/weekend characteristics of PM10 and PM2.5 concentration and metallic elements in Busan in the springtime of 2013. PM10 concentration on weekday/weekend were 77.54 and 67.28 ㎍/㎥, respectively. And PM2.5 concentration on weekday/weekend were 57.81 and 43.83 ㎍/㎥, respectively. Also, PM2.5/PM10 concentration ratio on weekdays/weekend was 0.75 and 0.65, respectively. The contribution rates of Na to total metallic elements in PM10 on weekday/weekend were 38.3% and 38.9%, respectively. It would be useful in control effectively with management of urban fine particle to understand characteristics of fine particle concentration on weekday/weekend.

The study investigates weekday/weekend characteristics of PM10 and PM2.5 concentrations and meteorological elements in Busan. The PM10 concentration is highest on Wednesday and Thursday, and lowest on Sunday. On the other hand, the PM2.5 concentration is highest on Wednesday and lowest on Sunday. The location where concentrations of weekdays and weekend differ the most is Hwakjang-dong, the industrial area, and where they differ the least is Gijang-up and Joa-dong, the residential area. Fine particle concentration in the industrial area was consistent at dawn and in the morning, but varied in the afternoon and at night. The visibility of Sunday was 0.49 km higher than that of weekdays, and the solar radiation of Sunday was 0.11 MJ/㎡ higher than that of weekdays. These results indicate that the concentration of fine particles had influence on the change of visibility and solar radiation.

This study analyzes the characteristics of ozone weekend effect(OWE) in Busan. O3 concentration on Sunday was over 10% higher than that on weekdays in all areas except for Kwangbokdong, Taejongdae, and Joadong. Such a difference was higher in the industrial area than in the residential area. O3 generation was facilitated by the decrease in NOx emission on Sunday in VOC-limited regime where the VOC/NOx ratio is low. Low NO concentration in the Sunday morning decreased inhibition of O3. NO-O3 crossover time on Sunday was shorter than that on weekdays which in turn extended the accumulated duration of O3. Future studies can include whether the entire Busan is VOCS-limited or the coastal area is VOCS-limited while the inland area is NOX-limited.

This study analyzes the chemical composition of metallic elements and water-soluble ions in PM10 and PM2.5. PM10 and PM2.5 concentrations in Busan during 2010-2012 were 97.2±67.5 and 67.5±32.8 ㎍/㎥, respectively, and the mean PM2.5/PM10 concentration ratio was 0.73. The contribution rate of water-soluble ions to PM10 ranged from 29.0% to 58.6%(a mean of 38.6%) and that to PM2.5 ranged from 33.9% to 58.4%(a mean of 43.1%). The contribution rate of sea salt to PM10 was 13.9% for 2011 and 9.7% for 2012, while that to PM2.5 was 17.4% for 2011 and 10.1% for 2012. PM10 concentration during Asian dust events was 334.3 ㎍/㎥ and 113.3 ㎍/㎥ during non-Asian dust events, and the PM10 concentration ratio of Asian Dust/Non Asian dust was 2.95. On the other hand, the PM2.5 concentration in Asian dust was 157.4 ㎍/㎥ and 83.2㎍/㎥ in Non Asian dust, and the PM2.5 concentration ratio of Asian Dust/Non Asian dust was 1.89, which was lower than that of PM10.

The purpose of this study was to analyze the effects of partial solar eclipse on 21 May 2012 in Korea on meteorological variables in Busan. 0800 LST(Local Standard Time) solar radiation was similar or lower than 0700 LST solar radiation, and sunshine duration decreased by 0.2∼0.5 hours in Busan and great cities under the influence of the partial solar eclipse. Temperature drop due to the partial solar eclipse was 0.2∼2.0℃, time taken to arrive at maximum temperature after onset of eclipse was 8∼62 minutes, and time taken to arrive at minimum temperature after maximum eclipse was -9∼17 minutes in Busan. Change of wind speed was negligible as partial solar eclipse occurred in the morning. Soil temperature of 5 ㎝was minute as well, the increase of soil temperature due to sunset was delayed by more than 1 hour.

The purpose of this study was to analyze the meteorological characteristics of wintertime high PM10 concentration episodes in Busan. PM10 concentration has been reduced for the past four years and recorded near or exceeded 100 ㎍/㎥ (national standard of PM10). High concentration episodes in Busan were 6 case, PM2.5/PM10 ratio was 0.36∼0.39(mean 0.55). High PM10 concentration occurred during higher air temperature, more solar radiation and sunshine, lower relative humidity, and smaller cloud amount. Synoptically, it also occurred when Busan was in the center or the edge of anticyclone and when sea breeze intruded. An analysis of upper air sounding showed that high PM10 concentration occurred when surface inversion layer and upper subsidence inversion layer existed, and when boundary layer depth and vertical mixing coefficient were low. An analysis of backward trajectory of air mass showed that high PM10 concentration was largely affected by long range transport considering that it occurs when air mass is intruded from China.

This paper examines the effects of the partial solar eclipse of 22 July 2009 across the Korean peninsular on surface temperature and ozone concentrations in over the Busan metropolitan region (BMR). The observed data in the BMR demonstrated that the solar eclipse phenomenon clearly affects the surface ozone concentration as well as the air temperature. The decrease in temperature ranging from 1.2 to 5.4℃ was observed at 11 meteorological sites during the eclipse as a consequence of the solar radiation decrease. A large temperature drop exceeding 4℃ was observed at most area (8 sites) of the BMR. Significant ozone drop (18∼29 ppb) was also observed during the eclipse mainly due to the decreased efficiency of the photochemical ozone formation. The ozone concentration started to decrease at approximately 1 to 2 hours after the event and reached its minimum value for a half hour to 2 hours after maximum eclipse. The rate of ozone fall ranged between 0.18 and 0.49 ppb/min. The comparison between ozone measurements and the expected values derived from the fitted curve analysis showed that the maximum drop in ozone concentrations occurred at noon or 1 PM and was pronounced at industrial areas.

The purpose of this study was to analyze the effects on meteorological variables in Seoul, Busan and Jeju during the partial solar eclipse event of 22 July 2009 in Korea. Solar irradiance decreased 16 and 19 minutes after eclipse in Seoul and Busan, and 6 minutes before eclipse in Jeju. Minimum solar irradiance occurred 7 and 3 minutes after maximum eclipse in Seoul and Busan, respectively, and 8 minutes before maximum eclipse in Jeju. Solar irradiance began to increase after maximum eclipse in Seoul and Busan, and recovered to the original state as eclipse ended. On the other hand, recovery of solar irradiance after maximum eclipse in Jeju was slower than those of two cities. Temperature drop due to partial solar eclipse were 0.7℃, 4.0℃, 1.5℃ in Seoul, Busan, and Jeju, respectively, and time needed to arrive minimum temperature from maximum eclipse were each 12, 32, 30 minutes, respectively. Change of relative humidity during partial solar eclipse were 2.6%, 17.4%, 12.3% in Seoul, Busan, and Jeju, respectively. Temperature drop turned out to be sharper as altitude increases. Wind speed decreased by each about 1.1 ㎧, 3.4 ㎧, 1.4 ㎧ due to partial solar eclipse in Seoul, Busan, and Jeju. Soil temperature of 5 ㎝ equally decreased by 0.2℃ in Seoul and Busan, soil temperature of 10 cm maintained almost constant, and soil temperature of 20 cm was hardly affected by eclipse.

The purpose of this study was to analyze the characteristics of spacio-temporal variation for PM10 and PM2.5 concentration in Busan. PM10 concentration has been reduced for the past three year and exceeded 50 ㎍/㎥ of the national standard for PM10. PM2.5 concentration showed gradual decrease or stagnant trends and exceeded the U.S. EPA standard. Seasonal analysis of PM10 and PM2.5 suggested spring>winter>fall>summer(by Asian dust) and winter>spring>summer>fall(by anthropogenic effect) in the order of high concentration, respectively. Characterization of diurnal variations suggests that PM10 levels at all the three sites consistently exhibited a peak at 1000LST and PM2.5 at Jangrimdong experienced the typical PM2.5 diurnal trends such that a peak was observed in the morning and the lowest level at 1400LST. In the case of seasonal trends, the PM2.5/PM10 ratio was in the order of summer>winter>fall>spring at all the study sites, with a note that spring bears the lowest concentration. During AD events, PM10 concentration exhibited the highest level at Jangrimdong and the lowest level at Joadong. And PM2.5/PM10 ratio in AD was 0.16∼0.28.

In order to understand chemical characteristics and formation of dewfall in Busan, we analysed monthly distribution of dewfall, and investigated its chemical composition of dewfall. This study used the modified teflon plate (1m × 1m) at Jangyongsil science high school from June 2005 to October 2005. In order to estimate qualitatively water soluble components, IC, ICP and UV methods for water soluble ions are also used respectively. Dewfall amount of sampling periods (26 day) collected 1.29 ㎜. Distribution of water soluble ions in dewfall founded the highest concentration (81.3 μeq/ℓ for NO3-, 146.6 μeq/ℓ for SO42-, and 114.3 μeq/ℓ for nss-SO42-) during the June. pH was the lowest by 5.12 June, and October (pH 6.68) by most high and average pH was 5.46. Monthly equivalent ratio of [SO42-]/[NO3-] showed the highest value (2.94) during the September, the lowest value (1.77) during the July, and the mean value was 3.45.

In order to understand chemical characteristics and dewfall formation in western Busan area, we analysed monthly distribution of dewfall, and investigated the correlation between dewfall formation amount and meteorological factors. This study used the modified teflon plate (1m×1m) at Silla university in Busan from August 2002 to April 2003. In order to estimate qualitatively water soluble components, IC, ICP and UV methods for water soluble ions are also used respectively. Dewfall amount of sampling periods (47 day) collected 3.8 ㎜. Meteorological conditions for the formation of dewfall above 50 g/m2 showed that temperature diurnal range(℃) was 5.6℃ above, cloud amounts (1/10) at dawn of the sampling day was 7/10 below, mean wind speed at dawn (0～6hr) of the sampling day was 4.4 m/sec below, and mixing ratio at 6hr of the sampling day was 3.2 g/kg above. Distribution of water soluble ions in dewfall founded the highest concentration (206.1 μeq/ℓ for SO42-, 42.4 μeq/ℓ for NH4+, 249.2 μeq/ℓ for Ca2+, and 42.0 μeq/ℓ for Mg2+) during the March, the lowest concentration (73.0 μeq/ℓ for SO42-, 4.6 μeq/ℓ for NH4+ and 72.7μeq/ℓ for Ca2+) during the August. Monthly equivalent ratio of [SO42-]/[NO3-] showed the highest value (4.99) during the October, the lowest value (1.84) during the August, and the mean value was 3.45.

Hourly data of PM10 concentration collected from nine automatic air quality monitoring stations in Busan from 1999 to 2002 were analyzed to evaluate the spatio-temporal variation and meteorological characteristics of PM10 episodes in Busan metropolitan area. Mean concentrations ranged from 47㎍/m3 to 77㎍/m3. For most stations, mean seasonal hourly concentrations are lowest in summer and highest in spring. PM10 episode above daily mean standard(150㎍/m3) exhibited a maximum frequency at Gamjeondong and a minimum at Dongsamdong, and a maximum in March and a minimum in July and August. The diurnal variation of PM10 episode days is strongly influenced by traffic loads and meteorological conditions.

The PM10 concentration and chemical composition in an western area of Busan were surveyed between March, 2001 and February, 2002. The mean concentration was 98.2 ㎍/㎥ with a range of 18.1 to 330.6 ㎍/㎥. The magnitude of metallic elements in PM10 is as follows in decreasing order: K>Ca>Na>Al>Fe. The mean values of crustal enrichment factors for four elements (Cd, Ni, Pb and Zn) were all higher than 10, which presumably resulted from the effect of anthropogenic origin. Moreover, the wintertime values were higher than springtime and summertime values, possibly due to emissions westerly transported from industries around this area. The contribution of soil particle to airborne particle in the study area was estimated to be 9.5%.

This study was performed to research ozone concentration related to airmass thunderstorm using 12 years meteorological data(1990～2001) at Busan. The occurrence frequency of thunderstorm during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence at summertime(59%). In case August 4, 1996, increase of ozone concentration was simultaneous with the decrease of temperature and increase of relative humidity. In case July 23, 1997, ozone concentration of western site at Busan increased, while its of eastern site decreased as airmass thunderstorm occurred(about 1500LST). It is supposed that these ozone increases are the effect of ozone rich air that is brought down by cumulus downdrafts from height levels where the ozone mixing ratio is larger. Thunderstorms can cause downward transport of ozone from the reservoir layer in the upper troposphere into planetary boundary layer(PBL). This complex interaction of source and sink processes can result in large variability for vertical and horizontal ozone distributions. Thus a variety of meteorological processes can act to enhance vertical mixing between the earth's surface and the atmospheric in the manner described for thunderstorm.

This study was performed to research the characteristics of suspended particulate for Yellow Sand of January, 1999 in Busan. Yellow Sand frequency during 13 years(1988~2000) in Busan showed maximum in April(57%), next to March(21%), May(16%). According to result of 850hPa weather map and backward isentropic trajectory, this event originated from the Gobi Desert and the Loess Plateau of China. And three mode was found in time series of TSP and PM10 concentration, primary peak showed the maximum hourly concentration at all station. Gamjeondong as industrial site showed the highest TSP concentration and also had the longest high concentration(≥700㎍/m3). In PM10, concentration of primary peak showed maximum value at Yeonsandong, maximum concentration of secondary and third peak was Deokcheondong. Lasted time from primary peak to secondary peak was about 30 hours, between secondary peak and third peak was 18 hours in Busan, The traveling time between occurrence of Yellow Sand the finding of it was 8~9 hours in Busan and 4~5 hours in central area.

The meteorological elements were measured to investigate cause of summertime ice formation at Unchiri, Gangwon Province. The cause of freezing at valley was conformed as adiabatic expansion theory, latent heat of evaporation, natural convective theory, cold air remain theory, and convective freezing theory according to former study. However nither theory produced a satisfactory explanation. This studying area is not valley but ridge, and underground water surface exists at below than freezing height. wintertime temperature drop and summertime cold air spouting were explain as natural convective theory, generation of water drop on the rock was explained as cooling theory by air expansion, and ice formation on the rock was explained as adiabatic expansion theory. In conclusion, formation of ice valley at Unchiri was formed by natural convective theory, adiabatic expansion theory, and latent heat of evaporation successively.