Numerical study of Asian dust transport during the springtime of 2001 simulated with the Chemical Weather Forecasting System (CFORS) model

Abstract

[1] The regional-scale aerosol transport model Chemical Weather Forecasting System (CFORS) is used for analysis of large-scale dust phenomena during the Asian Pacific Regional Characterization Experiment (ACE-Asia) intensive observation. Dust modeling results are examined with the surface weather reports, satellite-derived dust index (Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI)), Mie-scattering lidar observation, and surface aerosol observations. The CFORS dust results are shown to accurately reproduce many of the important observed features. Model analysis shows that the simulated dust vertical loading correlates well with TOMS AI and that the dust loading is transported with the meandering of the synoptic-scale temperature field at the 500-hPa level. Quantitative examination of aerosol optical depth shows that model predictions are within 20% difference of the lidar observations for the major dust episodes. The structure of the ACE-Asia Perfect Dust Storm, which occurred in early April, is clarified with the help of the CFORS model analysis. This storm consisted of two boundary layer components and one elevated dust (>6-km height) feature (resulting from the movement of two large low-pressure systems). Time variation of the CFORS dust fields shows the correct onset timing of the elevated dust for each observation site, but the model results tend to overpredict dust concentrations at lower latitude sites. The horizontal transport flux at 130°E longitude is examined, and the overall dust transport flux at 130°E during March-April is evaluated to be 55 Tg.

Mixture of Kosa (Asian dust) and bioaerosols detected in the atmosphere over the Kosa particles source regions with balloon-borne measurements: possibility of long-range transport

“…The tethered balloon used here has a volume of about 15 m 3 and potential payload of 10 kg at ceiling level of 4 km altitude. As suggested by Uno et al (2004) and Sun et al (2001), geographical features of the Tarim basin largely contributes to the formation of active local circulation systems which are effectively mixing atmospheric constituents up to the heights of the summit of mountains surrounding the Tarim basin (about 5 km), and westerly wind existing above the summit of mountains can easily transport those constituents long range. Iwasaka et al (2003a) suggested, on the basis the balloon-borne and lidar measurements made at Dunhuang, China, that westerly wind appeared clearly above about 5 km even in the summer season and that dust-like particulates were well mixed from near the ground to about 5 km due to active local circulations in the Taklamakan desert and after then transported long range by westerly wind.…”

“…As suggested by Sun et al (2001), Iwasaka et al (2003a), and Uno et al (2004), Taklamakan desert has large potential to inject dust particulate into the atmosphere and to transport those particle long range by westerly wind, even in the time without severe low pressure system, through active local circulations formed on the slope of the mountains surrounding the Tarim basin.…”

Size Distribution and Characteristics of Chemical Components in Ambient Particulate Matter

“…The occurrence and transportation of continental yellow sand from China to Japan were simulated using the Chemical Weather Forecasting System (CFORS) developed by Uno et al 24 These simulations suggested that the high concentrations of Si, Al, Ca, Mg, and Fe in Kyoto during these periods may be largely due to the effects of continental yellow sand from China (Fig. 8).…”

Determination of Upwind and Downwind Areas of Seoul, Korea Using Trajectory Analysis

“…SO 2 concentrations measured by a ship crossing the Yellow Sea are high only near the coastal areas but very low on the sea (Kim et al, 2010). Air-quality modeling demonstrates the transport of air pollutants over the continent and the ocean (Uno et al, 2004;Song and Carmichael, 2001), but its impact on the air quality at the surface level cannot be ascertained because of the limitations of the vertical grid resolution.…”