Observational Studies on Atmospheric Aerosols—Long-range Transport, Local Pollution, and Radioactive Aerosols—

Abstract

In this commemorative review article, an overview is presented of observational studies on atmospheric aerosols in which the author has engaged, and related studies that had preceded or competed with those of the author are briefly introduced. Outflow patterns and mechanisms of air pollutants from the Asian continent from winter to spring were studied by airborne and shipboard measurements in the early 1990s. At least two transport types of highly polluted air masses were found, which are driven by a synoptic-scale meteorological cycle. Early winter severe aerosol pollution in the Kanto Plain, Japan, in the 1990s was also formed and dissolved during the course of the meteorological cycle. Possible effects of long-range transport on PM_2.5 concentration in Northern Kyushu, Japan, were investigated by simultaneous monitorings at an urban site (Fukuoka) and on an island located upwind in the westerlies where no major emission sources existed (Fukue Island). The recent research subject with which the author has been involved is the physico-chemical form and an alternative deposition mechanism of radioactive aerosols released from the accident at the Fukushima Dai-ichi Nuclear Power Plant, a subject with which other researchers were not concerned in the early weeks and months after the accident.