Long-range transport of mineral dust observed with the Asian Dust and aerosol lidar observation Network (AD-Net)

Abstract

AD-Net is an aerosol observation network using continuously operated multi-parameter lidars consists of 20 stations in East Asia. It is a “contributing network” of the WMO Global Atmosphere Watch (GAW) Program and is an Asian component of the GAW Aerosol Lidar Observation Network (GALION). The standard lidars in AD-Net are two-wavelength (1064 and 532 nm) and polarization (532 nm) lidars, but multiwavelength Raman lidars and a multiwavelength high-spectral-resolution (532 nm) and Raman (355 nm) lidar are also employed. The Mie scattering data from the AD-Net lidars are processed in near realtime (every hour) and published on the AD-Net www page in NetCDF format and graphical indications. AD-Net data are used in monitoring and various studies of Asian dust and regional air pollution. Analyses combining with chemical transport models showed that dust affecting the lower troposphere in Japan was mostly from the Gobi Desert, and dust from the Taklamakan was often transported in the free troposphere very long range. A case of Sahara dust transported through the Middle East and Central Asia was also found. Asian dust transported through polluted areas in East Asia is often internally mixed with air pollution. Results of studies using AD-Net lidars, in-situ polarization particle counters (POPCs), and sampling measurements of chemical composition are introduced.