| Summary: | 碩士 === 國立臺灣海洋大學 === 海洋環境資訊系 === 107 === In this study, 11 sets of size-fractionated aerosol samples were collected and analyzed from Pengjia (remote island). From May 2015 to April 2016, 66 aerosol samples were collected; In this study, 106 rainwater samples were collected. Aerosol samples were analyzed to examine the water-soluble total nitrogen (WSTN), and major ions in the samples.Rainwater samples were analyzed to examine the total dissolved nitrogen (TDN).WSTN can be divided into water-soluble inorganic nitrogen (WSIN) and water-soluble organic nitrogen (WSON); TDN can also be divided into dissolved inorganic nitrogen (DIN) and dissolved organic nitrogen (DON). This study, we tried to understand the composition of WSON and DON, employed ultrafiltration to separate WSON and DON into low molecular weight-WSON(LMW-WSON), high molecular weight-WSON(HMW-WSON), low molecular weight-DON(LMW-DON), and high molecular weight-DON(HMW-DON). The concentrations of LMW-WSON accounted for 47 % of the WSON (the monthly average concentration of WSON was 148 nmol m-3). The concentrations of LMW-DON accounted 55% of the DON (the monthly average concentration of DON was 25μm;). The part of the fluxes, the WSIN (9.7±4.4 mmol m-2 yr-1) and WSON (30.0±27.4 mmol m-2 yr-1); DIN (40 mmolm-2 yr-1) and DON (24.8 mmol m-2 yr-1). In order to discuss the contribution of atmospheric nitrogen deposition to new production in the regional sea, this study consider the difference in bioavailability of different molecular weights of organic nitrogen in the past study. Base on the composition ratio of phytoplankton in distinct pools of high (low) molecular weight dissolved organic matter (>1 kDa，C/N：21；<1 kDa，C/N：6),dry and wet deposition can be converted to 4.92 g C m-2 yr-1 and5.79 g C m-2 yr-1 fixed by marine phytoplankton. This would account for 15.4% of new production in the regional sea annually, which is taken to be 69.5 g C m-2 yr-1 based on the particulate organic carbon export fluxes.
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