Summary of Abstract Submission

Abstract Submission No. IO50-03-0028PresentationPoster

ATMOSPHERIC DEPOSITION OF WATER-SOLUBLE TRACE METALS AND NUTRIENTS TO COASTAL ARABIAN SEA

Ashwini Kumar*1, C. Prakashbabu1, V. Ramaswamy1

1 CSIR-National Institute of Oceanography, Dona Paula, Goa-403004, India

ABSTRACT :

Atmospheric deposition is considered as a key process in controlling biogeochemical cycles in the coastal as well as remote oceans. This brings significant amount of macro (eg. nitrate, phosphate) and micro (Fe and other trace metals) nutrients to marine biota at the surface ocean, and thus, significantly modulate ocean primary productivity. It is presumed that the dissolved phase of trace metals in atmospheric deposition are directly available for phytoplankton. Apart from mineral dust, anthropogenic emissions have been also considered as an important contributor of trace metals in atmospheric outflow. In this context, atmospheric aerosols were collected at a coastal station in Goa (15.45oN, 48.80oE) during April, 2012 to May, 2013 to critically assess the concentration and deposition fluxes of trace metals and macro nutrients across the air-sea interface in the Eastern Arabian Sea. The samples were leached with deionized water and water-soluble (WS) major cations, anions and trace metals were measured using Ion Chromatography. Preliminary data shows the dominance of nss-Ca2+ and nss-SO42- among cations and anions, respectively. Higher nss-Ca2+ during summer (March-June) clearly indicates mineral dust intrusion at the study site. Higher concentration of WS-trace metals (Fe[III], Cu[II], Zn[II] and Mn[II]) were observed mostly during winter months (November-March) with presence of WS-Zn[II] throughout the study period. The synoptic winds during north-east monsoon (winter-time) brings continental air-mass enriched in chemical species derived from large scale anthropogenic activities via long-r