• 한국대기환경학회지
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• 제34권5호
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• pp.727-734
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• 2018

In this study, real-time absorption coefficients of carbonaceous species in $PM_{2.5}$ was observed using a dual-spot 7-wavelength Aethalometer between November 1, 2016 and December 31, 2017 at an urban site of Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were simultaneously collected at the same site and analyzed for organic carbon and elemental carbon (OC and EC) using the thermal-optical transmittance protocol. A main objective of this study was to estimate mass absorption cross section (MAC) values of black carbon (BC) particles at the study site using the linear regression between aethalometer-based absorption coefficient and filter-based EC concentration. BC particles observed at 880 nm is mainly emitted from combustion of fossil fuels, and their concentration is typically reported as equivalent BC concentration (eBC). eBC concentration calculated using MAC value of $7.77m^2/g$ at wavelength of 880 nm, which was proposed by a manufacturer, ranged from 0.3 to $7.4{\mu}g/m^3$ with an average value of $1.9{\pm}1.2{\mu}g/m^3$, accounting for 7.3% (1.5~20.9%) of $PM_{2.5}$. The relationship between aerosol absorption coefficients at 880 nm and EC concentrations provided BC MAC value of $15.2m^2/g$, ranging from 11.4 to $16.2m^2/g$. The eBC concentrations calculated using the estimated MAC of $15.2m^2/g$ were significantly lower than those reported originally from aethalometer, and ranged from 0.2 to $3.8{\mu}g/m^3$, with an average of $1.0{\pm}0.6{\mu}g/m^3$, accounting for 3.7% of $PM_{2.5}$ (0.8~10.7%). Result from this study suggests that if the MAC value recommended by the manufacturer is applied to calculate the equivalent BC concentration and radiative forcing due to BC absorption, they would result in significant errors, implying investigation of an unique MAC value of BC particles at a study site.

• 통합자연과학논문집
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• 제4권1호
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• pp.38-43
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• 2011

The recent global warming may be estimated to give lots of impacts to the human society and biosphere of influencing climate change included by the natural climate variations through the human activity which can directly and/or indirectly play a major role of total atmospheric composition overall. Therefore it currently appears evidences such as hot wave, typhoon, and biosphere disturbance, etc. over the several regions to be influenced by global warming due to increasing the concentration of greenhouse gases in the atmosphere through inducing forest destruction, fossil fuel combustion, greenhouse gases emission, etc. since industrial revolution era. Through the working group report of IPCC (Intergovernmental Panel on Climate Change) for climate change was analyzed by the individual country's current status and figure out the important issues and problems related to the future trend of climate change science with advanced countries preparedness and research, In this study, the first working group report of IPCC focuses on those aspects of the current understanding of the physical science of climate change that are judged to be most relevant to policymakers. As this report was assessed and analyzed by including the progress of climate change science, the role of climate models and evolution in the treatment of uncertainties. This consists of the changes in atmospheric constituents(both aerosols and gases) that affect the radiative energy balance in the atmosphere and determine the Earth's climate, considering the interaction between biogeochemical cycles that affect atmospheric constituents and climate change, including aerosol/cloud interactions, the extensive range of observations snow available for the atmosphere and surface, for snow, ice, and frozen ground and for the oceans, respectively and changes in sea level, the paleoclimate perspective and assessment of evidence for past climate change and the extension, the ways in which physical processes are simulated in climate models and the evaluation of models against observed climate, the development plans and methods of improving expert and building manpower urgently and R&D fund expansion in detail for climate change science in Korea will be proposed.