Background/Aims: Weather and air pollution are associated with the exacerbation of respiratory diseases. We investigated patterns of medical care use according to meteorological factors and air pollution in patients with asthma or chronic obstructive pulmonary disease (COPD). Methods: We analyzed the medical care utilization patterns of patients with asthma or COPD registered in the Korea Health Insurance Review and Assessment database for the period 2007 to 2013. The patterns were divided into hospitalization and emergency department (ED) use. Results:The medical care use of patients with asthma or COPD increased when the mean temperature and relative humidity were lower, and the temperature difference and atmospheric pressure were greater. Medical care use increased with the concentrations of particulate matter and ozone. Among age groups, sensitivity to pollutants was greatest in patients aged ≥ 65 years. The effect of being elderly was greater for asthma than for COPD, with a higher hospitalization rate. ED utilization affected by environmental factors was significantly greater for females and hospitalization was significantly more common for males. Conclusions: Meteorological factors and air pollutants were shown to contribute to increased medical care utilization by patients with asthma and COPD, particularly elderly patients. The overall effect was greater for COPD, but the effect in elderly patients was greater for asthma. In addition, the patterns of change in medical care use due to environmental factors differed according to sex.

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The meteorological impacts of intertidal land cover variation during summer and winter were simulated using the weather research and forecasting (WRF) meteorological model through two experiments: a TIDE experiment with time‐varying land cover by tidal effects in the intertidal zone using a new modeling method used hourly surface boundary conditions obtained using ocean model and satellite data, and a CNTL experiment with fixed land cover in the intertidal zone using a typical WRF modeling method used to fix the surface boundary conditions. The results of the TIDE experiment were more consistent with the recorded observations, especially during high tides. During summer daytime, the sensible heat flux (SHF) became negative (downward exchanging process) in the intertidal zone due to a low sea surface temperature, which decreased the temperature and increased the water vapor mixing ratio in the intertidal zone and inland areas. The wind speeds in intertidal zones and inland areas increased due to strong sea winds at altitudes from 80 m to 1.5 km, thereby increasing the sea breeze intensity and resulting in meteorological changes in inland areas. During winter, land cover changes in the intertidal zone impacted fog formation. During nighttime high tides, the SHF became positive in the intertidal zone and the latent heat flux increased prior to fog formation. During flood tide, the relative humidity increased and wind speed decreased in the intertidal zone and coastal areas coincident with fog occurrence. Overall, meteorological changes due to tidal effects were more pronounced in the summer.

In this study, the atmospheric dispersion of radioactive material ( 137 Cs) was simulated with regard to its impact within a 50-km radius from the Kori Nuclear Power Plant (NKPP) based on two different types of models (the nonsteady-state puff model CALPUFF and the lagrangian model HYSPLIT) during the spring of 2012 (May 2012). The dispersion distribution of 137 Cs calculated in the CALPUFF model was similar to that of the HYSPLIT model, but the magnitudes of differences in its spatio-temporal concentrations between the two models were different. The Cs concentrations simulated by the CALPUFF were significantly lower than those of the HYSPLIT due to a limitation of puff models (e.g. puff size growth over time). The CALPUFF had the advantage of determining the dispersion of radioactive materials and their impacts on the surrounding regions, compared with the HYSPLIT that had high concentrations of 137 Cs in only small local areas with the movement of air masses along the local winds.

The impact of land cover change in the intertidal zone (8.2% of the total surface area) on meteorology was evaluated using the Weather Research and Forecasting (WRF) model during summer (19-21 August 2016) and winter (9-11 February 2016). The heat flux change in the intertidal zone due to the tidal effects was greater in summer than in winter. During high tide in summer, the heat flux increased before sunrise and after sunset and decreased after sunrise and before sunset. During low tide, the overall heat flux decreased. In winter, a notable feature was the positive sensible heat flux before sunrise and after sunset during high tide due to a high sea surface temperature. The horizontal and vertical impacts of the tidal phenomena on the coastal meteorology were more pronounced during high tide than during low tide. The temperature decreased in inland areas and intertidal zone in summer afternoons, and increased at sea in winter mornings. The water vapor mixing ratio during the summer period increased in inland from the coastline. The wind speed during high tide at sea increased overall in summer and winter due to the decreased roughness length. During the summer period, the westerly wind speed significantly increased in the lower atmosphere (within 0.4 km) over coastal areas, and the easterly wind speed increased at the heights (approximately 1 km) of the return current of the sea breeze. These horizontal and vertical variations in sea breeze circulation induced horizontal meteorological differences in the Seoul metropolitan areas (approximately 30 km away from the coastline) and vertical differences within the planetary boundary layer (approximately 1.5 km altitude).