• Journal of Korean Society for Atmospheric Environment
• /
• v.7 no.2
• /
• pp.96-104
• /
• 1991

An investigation is carried out for the roles of the synoptic meteorology in governing $SO_2$ concentrations in Seoul during the wintertime. This study has used the daily records of wind and temperature measured at the Korea Meteorological Administration in Seoul. A one-dimensional diffusion model has been used for investigating the influence of the mixing height on the diurnal variation of concentration. The day to day variations of the concentration are well correlated with those of wind and temperature. The diurnal variation of the concentration is dictated by the variation of mixing height. It is also found that mesoscale wind field is required to explain the mesoscale distribution of the concentration.

• 한국해양학회지
• /
• v.19 no.2
• /
• pp.210-216
• /
• 1984

Diurnal variations of coastal surface wind speed are analyzed with five years of hourly wind from Port Aransas, Texas. These data reveal the highest frequency of occurrence of the nighttime wind maximum near midnight, especially during those seasons when onshore flow prevails. Nighttime wind maxima with a southerly component occurred approximately three times more frequently than with a northerly component on the annual average. The neutral atmospheric stability prevails near the coast. Thus it allows downward transfer of momentum from the nocturnal low level jet under the onshore wind situation and strong wind shear between an elevated frontal and ground-based inversion for offshore wind, resulting in the nocturnal coastal surface wind maximum.

• Journal of Microbiology
• /
• v.34 no.4
• /
• pp.300-304
• /
• 1996

To define the effects of zooplankton and phytoplankton to bacteria, bacterial numbers, frequency of dividing cells (FDC) and size distribution were performed with image analysis in the surface layer of Lake Soyang. In August 1992, when Anabaena was blooming, the bacterial number increased at daytime. Bacterial numbers and FDC value had a negative correlation (r = 0.83, P < 0.01). Bacterial size spectrums were dynamically changed during the day and night, especially the small bacteria less than $0.5\;{\mu}m^3$. Meanwhile, in October, after the bloom, the bacterial number was only one third of that in August, even though the FDC was higher than that in August. The bacterial numbers of small size class dropped at 13:00. But the size spectrums were relatively constant during the night time. These results suggest that the bacterial growth was tightly coupled with phytoplankton during Anabaena bloom. And after the bloom, the bacterial number was controlled grazing activity of zooplankton at daytime.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.04a
• /
• pp.45-54
• /
• 2003

This paper deal with the GPS performance for determining the ocean tidal loading components(M$_2$, N$_2$, S$_2$, K$_2$) and the availability of permanent GPS stations(CHJU, KANR) established in Korea. We determined the ocean tidal loading components from GPS observation by spectrum analysis and compared to that from global ocean tidal models(GOT00.2, FES99, CRS4.0, NAO99). Through this study, we have a sense that amplitude and phase lags of ocean tidal loading components from observed GPS data was almost equal to value calculated in ocean tide models. The diurnal ocean tide loading constituents are not considered, because unmodeled troposhere effects increase the noise level near the diurnal frequency band and prevent us from obtaining significant results.

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2002.11a
• /
• pp.127-131
• /
• 2002

The OJIP transients were investigated from leaves of Crinum asiaticum var. japonicum, Osmanthus insularis, Chloranthus glaber and Asplenium antiquum, in order to screen the indicators for quantification of environmental stresses and to apply them to the plant vitality test. The obvious diurnal changes or OJIP transients were found in Crinum asiaticum var. japonicum, Osmanthus insularis growing in sunny habitats, showing lower Fp and higher Fo in day time. The values of SF $I_{no}$ and P $I_{NO}$ increased dramatically in day time in leaves of Crinum asiaticum var. japonicum, Osmanthus insularis, and Asplenium antiquum. Although the value of RC/CS decreased slightly in day time in leaves of 4 tropica $l_tropical plants, the obvious diurnal changes or OJIP transients were not seen in winter, suggesting that tropica $l_tropical paints used in this research seemed to be irreversibly damaged in winter. However, the values of ETo/RC and Ψo/(1-Ψo) increased significantly in leaves of Crinum asiaticum var. japonicum, indicating that ETO/RC and Ψo/(1-Ψo) were useful as indicator parameters for scensing of low temperature.ature.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.4
• /
• pp.48-53
• /
• 2010

Roadside measurement of ultrafine particles, black carbon, and NOx was carried out to investigate air pollution at a junction area contaminated with vehicle emissions in Seoul from March 19 to 23, 2007. Diurnal variation of ultrafine particles, black carbon, and $NO_x$ concentrations at a roadside showed minimum at around 2-4 a.m. and two peak modes during the morning and evening rush hours. Since these pollutants might be mainly emitted from vehicles, the roadside was highly contaminated with vehicles.

• Journal of Ocean Engineering and Technology
• /
• v.16 no.2
• /
• pp.6-9
• /
• 2002

The long-term monthly variations of tide with tidal harmonic analysis in Pusan Harbour are investigated. The present spring tidal range decreased 1.4 cm and the variation of phase lag increased than 1974. The high and low water level of yearly mean sea level is show during the February to March and August to September, respectively. It is important to note that the larger lunar elliptic N2 is large in comparison with lunisolar diurnal K1 and principal lunar diurnal O1. The ratios (Correction Factors) of monthly mean sea level and the main 4 tidal constituents are evaluated to correct the shortly (monthly) observed tide for the design of harbour facilities.

• Journal of Environmental Science International
• /
• v.2 no.2
• /
• pp.103-113
• /
• 1993

The land and sea breeze over the Pusan coastal area is studied by three dimensional mesoscale numerical model. According to the results of the simulation experiments, both Pusan areas and Kimhae areas, the sea breeze began at 0800LST and the strongest at 1500LST and then at 1800LST. After midnight, the sea breeze changed about the land breeze and become weaker than that of the sea breeze in the daytime. Comparisons between calculations and observations showed that the characteristics of diurnal variation and v-component of the wind velocity relatively is similar to the Pusan areas. On the Kimhae areas, however, observations showed time lag which compared to the results of simulation experiments in the velocity of sea breeze and diurnal variation. From the above results, comparisons between calculations and observations is much more similar to the coastal areas than on the inland area.

• 한국해양학회지
• /
• v.23 no.2
• /
• pp.62-69
• /
• 1988

Analyzing short-term records of sea level data, we show that the amplitudes of diurnal tides along the southern coast of Jeju-Do are significantly larger than those along its northern coast. The amplitude-phase diagrams of $K_1$ and $O_1$ look very similar to that of $M_2$ shown by Kim and Lee (1986), indicating characteristics of the scattering of long waves by Jeju-Do.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2005.11a
• /
• pp.268-269
• /
• 2005