Evaluation of East Asian PM2.5 concentrations in MERRA-2 GMI
Abstract
The concentration of PM2.5 (Particulate Matter with aerodynamic diameter ≤ 2.5 μm) driven from the Global Modeling Initiative (GMI) chemistry transport model integrated with Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) is evaluated with in situ measurements in China, South Korea, and Japan. The PM2.5 concentrations for 2001-2016 are generally underestimated in the MERRA-2 GMI, except for Japanese sites. This negative bias has declined over recent years, but is still considerable in eastern China. An underestimation becomes more apparent in winter especially in the metropolitan area such as Beijing; the simulated PM2.5 concentration is only half of the observations. The observed PM2.5 concentrations are highly correlated with the simulated ones at polluted days (the daily-mean PM2.5 concentration is greater than 25 μg m-3; WMO guideline) than those at clean days. It is also found that the time when the largest underestimation appears in a day depends on the regions. While the maximum bias appears at noon in Beijing, it is observed at midnight in Chengdu, Shanghai, Shenyang, and Seoul. These results demonstrate that the PM2.5 concentrations of MERRA-2 GMI can be used only in qualitative sense in East Asia.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A21G2724J
- Keywords:
-
- 0317 Chemical kinetic and photochemical properties;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0322 Constituent sources and sinks;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES