Objective and approach

Primary objective of AD-Net is to observe vertical distributions of Asian dust and other aerosols (including industrial, forest fire, volcanic) continuously, for studying the effects of aerosols on the environment in East Asia. The targets of our study include quantitative understanding of Asian dust emission, transport and deposition, long-term variation of Asian dust and anthropogenic aerosols, effects of aerosols on human health, vegetation, and atmospheric radiation.

Continuous observation with automatic lidars is our approach. The standard lidar system in AD-Net is a two-wavelength (1064 nm, 532 nm) polarization sensitive (532 nm) Mie-scattering lidar (Sugimoto et al., 2008).

The measured data are transferred to the National Institute for Environmental Studies, Japan (NIES) in realtime and processed automatically. Basic parameters derived are the attenuated backscattering coefficients at 1064 nm and 532 nm, and the volume depolarization ratio at 532 nm. Extinction coefficient estimates for non-spherical and spherical aerosols are also derived with the method using the backscattering and depolarization ratio (Sugimoto et al., 2003; Shimizu et al., 2004).

For quantitative analysis of aerosol optical characteristics, receivers for nitrogen Raman scattering at 607 nm were added to the lidars at primary stations. Also, some stations are collocated with SKYNET skyradiometers.

Shimizu, A., N. Sugimoto, I. Matsui, K. Arao, I. Uno, T. Murayama, N. Kagawa, K. Aoki, A. Uchiyama, and A. Yamazaki, Continuous observations of Asian dust and other aerosols by polarization lidar in China and Japan during ACE-Asia, J. Geophys. Res., 109, D19S17, doi:10.1029/2002JD003253, 2004.

Sugimoto, N., I. Uno, M. Nishikawa, A. Shimizu, I. Matsui, X. Dong, Y. Chen, H. Quan, Record Heavy Asian Dust in Beijing in 2002: Observations and Model Analysis of Recent Events, Geophys. Res. Lett. 30, 12, 1640, doi:10.1029/2002GL016349, 2003.

Sugimoto, N., I. Matsui, A. Shimizu, T. Nishizawa, Y. Hara, C. Xie, I. Uno, K. Yumimoto, Z. Wang, S.-C. Yoon, Lidar Network Observations of Troposheric Aerosols, SPIE Vol. 7153, 2008 doi: 10.1117/12.806540.