Characterization of Asian dust and Siberian smoke with multi‐wavelength Raman lidar over Tokyo, Japan in spring 2003

Abstract

In the spring of 2003, we observed lofted Asian dust and Siberian forest‐fire smoke plumes in the free troposphere over Tokyo, Japan with a dual‐wavelength Raman lidar. These data show clear signatures of the optical characteristics depending on the aerosol type. The Asian‐dust layer shows that the particle depolarization ratio (PDR) at 532 nm is ∼20%, and the extinction‐to‐backscatter ratio (lidar ratio) at 355 nm is ∼49 sr, which is close to ∼43 sr measured at 532 nm. On the contrary, the smoke layers show that the PDR is as small as 5–8% or less, and the lidar ratio at 355 nm is ∼40 sr, which is considerably lower than ∼65 sr which was measured at 532 nm. We also applied an inversion algorithm for the smoke case. The effective radius was ∼0.22 μm and the single‐scattering albedo at 532 nm was ∼0.95.