https://repository.kopri.re.kr/handle/201206/5518 2026-04-28T16:17:49Z https://repository.kopri.re.kr/handle/201206/6361 Title: Quantification of coastal new ultra-fine particles formation from in situ and chamber measurements during the BIOFLUX campaign Authors: Sellegri; Hoffmann; Chen; Jennings; ODowd; Cautenet; Pirjola; Yoon, Y. J. Abstract: New particle formation processes were studied during the BIOFLUX campaign in September 2003 and June 2004. The goals were to bring new information on the role of I-2 in new particle formation from seaweeds and to quantify the amount of I-2 emitted and new particles formed by a given amount of seaweed. These two goals were achieved by using a simulation chamber filled with selected species of seaweeds from the Mace Head area and flushed with particle-free atmospheric air. It was found that total particle concentrations and particles in the 3-3.4 nm size range produced in the chamber are positively correlated with gaseous I-2 concentrations emitted by the seaweeds, with a typical source rate of 2800 particles cm(-3) ppt((I2))(-1) in the 3-3.4 nm size range. In fact, I-2 and particle concentrations are also both directly positively correlated with the seaweed mass (64 300 particles cm(-3) formed per kg of seaweed, and 24 ppt of I-2 per kg of seaweeds) until saturation was reached for a seaweed biomass of 7.5 kg m(-2). From the chamber experiments, the flux of 3-3.4 nm particles was calculated to be 2.5 x 10(10) m(-2) s(-1) for a seaweed loading of 2.5 kg m(-2) (representative of a typical seaweed field density), decreasing to 1 x 10(10) m(-2) s(-1) for a seaweed loading of 1 kg m(-2). At a seaweed loading of 2.5 kg m(-2), the growth rate of particles produced in the chamber was calculated to be 1.2 nm min(-1). The source rates and growth rates determined from the chamber experiments were used in conjunction with seaweed coverage in and around Mace Head to produce local emission inventories for a meso-scale dispersion model. Comparison of the resulting aerosol size distributions from the model simulations and those observed exhibited good agreement suggesting that the chamber fluxes and growth rates are consistent with those associated with the tidal emission areas in and around Mace Head. 2005-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6362 Title: Modelling iodine particle formation and growth from seaweed in a chamber Authors: ODowd; Prijola; Sellegri; Yoon, Y. J. Abstract: A sectional atmospheric chemistry and aerosol dynamics box model (AEROFOR) was further developed and used to simulate ultra-fine particle formation and growth from seaweed in a chamber flushed with particle-free atmospheric air. In the model, thermodynamically stable clusters were formed by dimer nucleation of OIO vapour, whose precursor was assumed to be molecular I-2 emitted by seaweed. Fractal geometry of particles was taken into account. For the I-2 fluxes of (0.5-1.5) x 10(9) cm(-3) s(-1) the model predicted strong particle bursts, the steady state concentrations of I-2 vapour and particles larger than 3 nm were as high as 4 x 10(9)-1.2 x 10(10) cm(-3) and 5.0 x 10(6)-9.2 x 10(6) cm(-3) respectively. The steady state was reached in less than 150 s and the predicted growth rates of 3-6 nm particles varied in the range of 1.2-3.6 nm min(-1). Sensitivity of the size distribution against I2O3 cluster formation, an extra condensable vapour, the photolysis rate of the OIO vapour as well as against the density of (OIO)(n)-clusters was discussed. The modelled results were in good agreement with the chamber measurements performed during the BIOFLUX campaign in September, 2003, in Mace Head, Ireland, confirming that I-2 emissions and nucleation of iodine oxides can largely explain the coastal nucleation phenomenon. 2005-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6632 Title: Surface Flux Measurements at King Sejong Station in West Antarctica: Ⅱ. Turbulent exchanges of sensible heat and latent heat in the austral summer of 2002-2003 Authors: Choi, Taejin; Lee, Bang Yong; Kim, Seong-Joong; Hong, Sung-Min; Lee, Hee-Choon Abstract: Turbulent fluxes of sensible heat and latent heat were analyzed at King Sejong station in the austral summer of 2002 (December) and 2003 (January and February). Monthly mean air temperatures of January and February (2.2oC) were similar to those averaged over 1988 to 2001. Precipitation wasless in January and greater in February than those averaged over last 14 years. In December of 2002 and January, there was precipitation primarily when easterly wind blew usually. The frequency of snowfallwas equal to or larger than that of rainfall. In the mean while, precipitation primarily in forms of rainfall occurred with westerly wind in February. In addition, while for easterly wind, temperature and humidity was low, temperature and humidity were high in case of westerly wind. Based on flux footprint,measured flux mainly came from within 300 m with maximum of 40 m upwind, indicating the insignificant role of the sea around the study site. Half-hourly downward short wave radiation amounted up to∼ 1000 Wm-2 and net radiation ranged from -50 to 600 Wm-2. Half-hourly sensible heat flux waspositive at daytime with maximum of ∼ 400 Wm-2, except the 27th and 28th in February of 2003 when it was negative all day despite of positive net radiation at short daytime. Latent heat flux was positive with maximum of ∼ 130 Wm-2. Depending on wind direction, the partitioning of net radiationinto the sum of sensible heat flux and latent heat flux was larger than 0.8, indicating the strong source of the land surface for the atmospheric heating. The daytime averaged Bowen ratio (=sensible heat flux /latent heat flux) was significantly greater than 1, indicating that sensible heat flux was the main source to heat the atmosphere over the site. 2005-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6631 Title: Climatic Characteristics Related with Sedimentary Process in Bransfield Strait, Antarctica Authors: Lee, Bang Yong; Lee, Jeong Soon; 윤영준; Yoon, Ho Il; 권태영 Abstract: This study examines the relationships among sea ice concentration, surface air temperature, surfacewind, and SST (Sea Surface Temperature) in Bransfield Strait to understand the climatic characteristicsand its related sedimentary process there. In analyses of the monthly data, during the austral autumn(Mar., Apr., and May), the frequency of southeasterlies is correlated positively with the sea ice concentrationand negatively with the surface air temperature, whereas that of northwesterlies is reverse. Theserelationships are explained by the process that the southeasterlies of the cold air from the AntarcticContinent affect the ocean current around Bransfield Strait. And then the ocean current makes thesea ice generated in the Weddell Sea drift into the strait. During the spring (Sep., Oct., and Nov.),sea ice concentration and surface air temperature are closely correlated with the frequency ofnorthwesterlies with warm air mass. In the some parts of the northern boundary region, the sea iceconcentration in Bransfield Strait is positively correlated with the SST during the autumn and spring.Such relationship may rather propel the sea ice melting in proportion to the sea ice concentrationduring the autumn. 2005-01-01T00:00:00Z