摘要

A bias in clear-sky conditions that will be involved in estimating particulate matter (PM) concentration from aerosol optical depth (AOD) was examined using PM10 from two Aerosol Robotic Network sites in Korea. The study periods were between 2004 and 2007 at Anmyon and between 2003 and 2011 at Gosan, when both PM10 and AOD were available. Mean PM10 when AOD was available (PMAOD) was higher than that from all PM10 data (PMall) by 5.1 and 9.9 mu g/m(3) at Anmyon and Gosan, which accounted for 11% and 26% of PMall, respectively. Because of a difference between mean PM10 under daytime clear-sky conditions (PMclear) and PMAOD, the variations in.PM10, the difference of PMall from PMclear rather than from PMAOD, were investigated. Although monthly variations in Delta PM10 at the two sites were different, they were positively correlated to those in Delta T, similarly defined as. PM10 except for temperature, at both sites Delta PM10 at Anmyon decreased to a negative value in January due to an influence of the Siberian continental high-pressure system while Delta PM10 at Gosan was high in winter due to an effect of photochemical production at higher temperatures than at Anmyon.