제주-대한해협 해역에서 에어로졸의 화학적 특성과 침적

Abstract

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO3-, non-sea-salt (nss)-SO42-, and NH4+ in aerosols were 2.19, 5.59, 6.16 and 2.08 μg m-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO3-/nss-SO42- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NOx and SOx emitted from China, Korea and Japan. The equivalent concentration ratio of [NH4+]/[nss-SO42- + NO3-] with the average of 0.58±0.29 indicates that nss-SO42- and NO3- are not neutralized by NH4+. A high activity concentration of 210Pb with 1.13–1.23 mBq m-3 was observed during the high yellow dust period, indicating that 210Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of 7Be and NH4+ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×106 tons yr-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH4+ and NO3- was 0.103 mole N m-2 yr-1 was estimated to support 4% of the annual primary productivity in the East China Sea.