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        검색결과 10

        1.
        2001.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 도식에 식재된 두 침엽수조인 소나무와 잣나무 단목의 연간 CO2, SO2, NO2 흡수 및 O2 생산을 계량화하는 것이다. 자연환경 조건하에서 운반형 적외선가스분석기로 연간 CO2교환율을 측정하여 CO2흡수 및 O2 생산량을 그리고 CO2와 SO2EH는 NO2간 흡수속도비를 적용하여 SO2 및 NO2흡수량을 각각 산정하였다. 흉고직경을 독립변수로 단목의 생장에 다른 연간 CO2흡수 및 대기 정화량을 추정하는 활용 용이한 방정식을 유도하였다. 연구대상 수목 중, 흉고직경 20cm인 잣나무는 연간 양 35kg의 CO2, 11g의 SO2, 19g의 NO2를 각각 흡수하였고 25kg의 O2를 생산하였다. 동일 직경의 소나무는 유도한 방정식을 적용하면, 연간 약 30kg의 CO2, 9g의 SO2, 15g의 NO2를 각각 흡수하였고 22kg의 O2를 생산하였다. 생상기간 중 단위엽면적당 CO2흡수량은 잣나무가 소나무보다 적었으나, 단목의 연간 CO2흡수 및 대기정화량은 총엽면적의 차이로 잣나무가 동일 직경의 소나무보다 많았다. 본 연구결과는 도시 침엽수의 연간 대기정화 가치를 용이하게 계량화학고 도시공간내 수목식재의 환경적 중요성을 홍보하는데 활용될 수 있다.
        4,000원
        2.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        A model coupling a meteorological predictive model and a vegetation photosynthesis and respiration model was used to simulate CO2 concentrations over coastal basin areas, and modeling results were estimated with aircraft observations during a massive sampling campaign. Along with the flight tracks, the model captured the meteorological variables of potential temperature and wind speed with mean bias results of 0.8℃, and 0.2 m/s, respectively. These results were statistically robust, which allowed for further estimation of the model’s performance for CO2 simulations. Two high-resolution emission data sets were adopted to determine CO2 concentrations, and the results show that the model underestimated by 1.8 ppm and 0.9 ppm at higher altitude over the study areas during daytime and nighttime, respectively, on average. Overall, it was concluded that the model’s CO2 performance was fairly good at higher altitude over the study areas during the study period.
        3.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        The Weather Research and Forecasting (WRF) model and Vegetation Photosynthesis and Respiration Model (VPRM) were coupled to simulate atmospheric CO2 concentrations. The performance of the WRF-VPRM to simulate regional scale CO2 concentration was estimated over coastal basin areas. Either Hestia 2011(HST) or Vulcan 2002(VUL) anthropogenic CO2 emission data were used in two numerical experiments for the study regions. Simulated meteorological variables were validated with ground and background CO2 measurement data, and the results show that the model captured temporal variations of CO2 concentration on a daily basis. CO2 directional analysis revealed that the dominant CO2 emission sources are located S and SW. The simulated Net Ecosystem Exchange (NEE) agreed relatively well with measured CO2 fluxes at each vegetation class site, showing approximately 40% at max improvement at shrub areas.
        4.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        The effects of CO2 enrichment on growth of maize (Zea mays L.) were examined. Parameters analyzed include growth characteristics, yields, photosynthetic rates, evaporation rates and photosynthesis-related characteristics under elevated CO2 . The plants were grown in growth chambers with a 12-h photoperiod and a day/night temperature of 28/21~circC at the seedling stage and 30/23~circC from the silking stage. The plants were exposed to two elevated CO2 of 500, 700ppm and ambient levels (350 ppm). Chalok 1 and GCB 70 germinated three days after seeding, and germination rates were faster in the elevated CO2 than the control. Germination rates displayed significant differences among the CO2 treatments. At the seedling stage, leaf area, top dry weight, and photosynthetic rates, and plant height indicated positive relationship with elevated CO2 concentrations. At the 5~6 leaf stage, CO2 concentration also indicated positive relationship with plant height, leaf area, top dry weight, and photosynthetic rates. At the silking stage, increased plant height of Chalok 1 was noted in the CO2 treatments compared to the control. No significant differences were noted for GCB 70, in which leaf area decreased but photosynthetic rates increased progressively with CO2 concentration. Stomatal aperture was a little bigger in the elevated CO2 than the control. CO2 concentration was negatively related to stomatal conductance and transpiration rates, resulting in high water use efficiency.
        8.
        1998.02 KCI 등재 서비스 종료(열람 제한)
        The present study intends to investigate the transient response of an atmosphere/ocean general circulation model to a gradual increase of atmospheric carbon dioxide. To detect the climatic change of the surface air temperature due to gradual increasing carbon dioxide for 100 years, two runs of GFDL CGCM for 1 % CO_2 run with increasing CO_2 and the control run with fixed CO_2 are compared. From results it is noted that the transient response of surface air temperature is more increased over the Northern Hemisphere than the Southern Hemisphere. However, in Northern Hemisphere the transient response of the surface air temperature due to the gradual increase of atmospheric carbon dioxide is slowly increased with latitudes and is clearly larger over continents than oceans. The annual global mean temperature is continuously increased with 0.03552 per one year with strong S/N ratio and distinguished from the natural variability. The time dependent response of the gradual increasing CO_2 has the strong seasonal variability with small change in summer and large change in winter, and the strong regionality in the Asian and the American continents. It has been suggested that the direct and the feedback processes in the climate systems should be investigated by the detailed sensitivity runs to get the meaningful estimate of the CO_2 forced variability.
        9.
        1994.12 KCI 등재 서비스 종료(열람 제한)
        This paper presents the disributions and variations of CO,CO_2, number of people and temperature in underground shopping center and subway of Seomyeon and Jagalchi in Pusan, Korea for two times during October and November in 1993, respectively. NDIR analyzer is used for the analysis of CO and CO_2. The temperature is obtained from a mercury therometer. The results of observation and analysis show that the variation of CO_2 is strongly related to number of people and temperature. The correlation coefficients between temperature, CO_2 and number of people are higher than 0.85 at both of places. The pollution of CO_2 of Seomyeon is higher than that of Jagachi in underground shopping center. However, CO is not correlated with the temperature and the number of people. From the results, we found that the indoor air quality monitoring system is needed for the prevention of the underground air pollution.
        10.
        1991.04 KCI 등재 서비스 종료(열람 제한)
        The atmospheric carbon dioxide concentration is ever-increasing and expected to reach about 600 ppmv some time during next century. Such an increase of CO2 may cause a warming of the earth's surface of 1.5 to 4.5~circC , resulting in great changes in natural and agricultural ecosystems. The climatic scenario under doubled CO2 projected by general circulation model of Goddard Institute for Space Studies(GISS) was adopted to evaluate the potential impact of climate change on agroclimatic resources, net primary productivity and rice productivity in Korea. The annual mean temperature was expected to rise by 3.5 to 4.0~circC and the annual precipitation to vary by -5 to 20% as compared to current normal climate (1951 to 1980), resulting in the increase of possible duration of crop growth(days above 15~circC in daily mean temperature) by 30 to 50 days and of effective accumulated temperature(EAT=∑Ti, Ti~geq 10~circC ) by 1200 to 1500~circC . day which roughly corresponds to the shift of its isopleth northward by 300 to 400 km and by 600 to 700 m in altitude. The hydrological condition evaluated by radiative dryness index (RDI =Rn/ ~ell P) is presumed to change slightly. The net primary productivity under the 2~times CO2 climate was estimated to decrease by 3 to 4% when calculated without considering the photosynthesis stimulation due to CO2 enrichment. Empirical crop-weather model was constructed for national rice yield prediction. The rice yields predicted by this model under 2 ~times CO2 climatic scenario at the technological level of 1987 were lower by 34-43% than those under current normal climate. The parameters of MACROS, a dynamic simulation model from IRRI, were modified to simulate the growth and development of Korean rice cultivars under current and doubled CO2 climatic condition. When simulated starting seedling emergence of May 10, the rice yield of Hwaseongbyeo(medium maturity) under 2 ~times CO2 climate in Suwon showed 37% reduction compared to that under current normal climate. The yield reduction was ascribable mainly to the shortening of vegetative and ripening period due to accelerated development by higher temperature. Any simulated yields when shifted emergence date from April 10 to July 10 with Hwaseongbyeo (medium maturity) and Palgeum (late maturity) under 2 ~times CO2 climate did not exceed the yield of Hwaseongbyeo simulated at seedling emergence on May 10 under current climate. The imaginary variety, having the same characteristics as those of Hwaseongbyeo except growth duration of 100 days from seedling emergence to heading, showed 4% increase in yield when simulated at seedling emergence on May 25 producing the highest yield. The simulation revealed that grain yields of rice increase to a greater