Characterization of soil dust aerosol in China and its transport and distribution during 2001 ACE‐Asia: 2. Model simulation and validation

Abstract

A size‐segregated soil dust emission and transport model, Northern Aerosol Regional Climate Model (NARCM), was used to simulate the production and transport of Asian soil dust during the Aerosol Characterization Experiment‐Asia (ACE‐Asia) period from March to May 2001. The model is driven by the NCEP reanalyzed meteorology and has all the atmospheric aerosol physical processes of soil dust: production, transport, growth, coagulation, and dry and wet deposition. A Chinese soil texture map that infers the soil grain‐size distribution with 12 categories was generated to drive the size‐distributed soil dust emission scheme [Alfaro et al., 1997; Marticorena and Bergametti, 1995]. The size distribution of vertical dust flux was derived from the observed surface dust‐size distribution in the desert regions. Parameters applicable to the Asian deserts for the dust emission scheme are assessed. Model simulations were compared with ground‐based measurements in East Asia and North America and with satellite measurements for the same period of time. The model captured most of the dust mobilization episodes during this period in China and reasonably simulated the concentrations in source regions and downwind areas from East China to western North America. About 252.8 Mt of soil dust below d < 40 μm was estimated to be emitted in the East Asian deserts between 1 March and 31 May 2001 with ∼60% attributed to four major dust storms. The vertical dust loadings above 700 hPa correlate reasonably well with Total Ozone Mapping Spectrometer aerosol index (TOMS AI) observations. The sensitivity analysis of model performance to soil size distribution, water moisture, and meteorology was carried out with the observational data to establish the most appropriate parameters and conditions for the Chinese soil dust production and transport.

Study of Aerosol Optical Properties Based on Ground Measurements over Sichuan Basin, China

“…Combined with the variations in AOD, the main reason for high AOD but low Ångström exponent in spring is the long-distance transport of dust particles from the north and northwest of China Gong et al, 2003). Convective precipitation occurs frequently in summer with the majority of coarse particles eliminated by wet settlement.…”

“…Large AOD values appeared in the winter and spring and ranged from 0.45 to 0.47, from 0.53 to 0.55, from 0.72 to 0.74 and from 1.07 to 1.13 for each wavelength, respectively. In spring, the Sichuan Basin region could be affected by dust storms from North China (Gong et al, 2003), which could contribute high AOD over the Basin. While in winter, the cold air has weak effect on the Sichuan Basin, aerosol particles from local pollution sources could not diffuse well.…”

“…8(a) illustrates the paths of air mass motion for the dusty day. Both the air masses of 500m and 1000 m above ground level on April 25 th , 2009 passed through the Gobi and deserts of North China, which are considered to be the major sources of Asian dust in spring (Gong et al, 2003;Zhang et al, 2003). Fig.…”

Sensitivity Experiments on the Effects of Optical Properties of Dust Aerosols on Their Radiative Forcing under Clear Sky Condition

“…Among them, some studies (Zhang et al 2003 have showed that the DS3 is the strongest one with the longest transportation from East Asia crossing Pacific Ocean to the west coast of America, which is called as ''perfect dust storm''. In this paper we mainly focused on this dust storm to evaluate the radiative forcing over East Asia and North Pacific region (75 E-225 W, 16-70 N) and examine the impacts of dust optical properties on it.…”

Size Distribution and Optical Properties of Particulate Matter (PM10) and Black Carbon (BC) during Dust Storms and Local Air Pollution Events across a Loess Plateau Site

“…For the coarse-mode particles, N 1-10 was not only very high in the cold season but also remained at its highest number concentration in spring, which is characterized by local soil dust or dust events. Gong et al (2003) noted that ~252.8 Mt of soil dust was estimated to have been produced in the East Asian deserts in a spring season, with ~60% of this being due to four major dust storms. When dust storms occur over northern China, N 1-10 can increase sharply.…”