Collaborative Research: Biogeochemistry of Trace Elements in the Western Pacific: Atmospheric Input and Upper Ocean Cycling

虽然先前在大西洋和阿拉伯海的研究已经证明了大气粉尘沉积与地表水中活性微量元素添加之间的直接关系，但对亚洲粉尘羽对北太平洋西部地表水中活性微量元素分布的影响知之甚少。因此，夏威夷大学、老道明大学和佛罗里达州立大学的研究人员将在2002年4月至5月期间参加一次前往北太平洋中部和西部的巡航，这段时间恰逢该地区的亚洲尘埃最多。在这次巡航期间，将实现以下四个研究目标：(1)利用地表水样品中的溶解铝浓度量化该地区大气尘埃的面积范围和浓度，并将结果与2001年ACE-ASIA项目的一部分进行的实地研究以及历史沉积模型所获得的估计结果进行比较；(2)比较气溶胶和雨水中生物活性微量金属的溶解度及其在地表水样品中的浓度和分布与Al值，以评估大气沉积在控制/改变这些元素的上层海洋生物地球化学循环中的作用；(3)确定大气输入进入北太平洋温跃层和中央水域的幅度和途径；(4)提供痕量金属的基线浓度。在航行过程中，pi将通过安装在改进的深海温度仪和垂直剖面上的聚四氟乙烯内衬聚乙烯管向船上泵水来收集表面样本，这些观测站将包括该地区的主要水文系统。样品（总、颗粒、溶解、胶体）将分析金属Ag、Al、Cd、Cu、Co、Fe、Mn、Ni、Pb、Zn和类金属As、Sb、Se。气溶胶和降雨样本也将分别收集和分析金属/主要离子和金属/类金属。此外，还将对选定的样品进行营养物质、盐度、氧气、叶绿素a、颗粒有机碳、颗粒有机氮、颗粒有机硫、溶解有机碳和溶解有机氮的分析。

ABSTRACTOCE-0117917OCE-0117655OCE-0117648While previous studies in the Atlantic Ocean and Arabian Sea have documented a direct relationship between atmospheric dust deposition and reactive trace element additions to surface waters, little is known about the effect that the Asian dust plume has on the distribution of reactive trace elements in surface waters of the western North Pacific. For this reason, PIs from the University of Hawaii, Old Dominion University and Florida State University will participate in a cruise to the central and western North Pacific during April/May 2002, a time period coincident with maximum Asian dust over that region. During this cruise the following four research objectives will be addressed: (1) quantify the areal extent and concentration of atmospheric dust in this region using dissolved Al concentrations in surface water samples and compare results with estimates obtained during field studies carried out as part of the ACE-ASIA program in 2001, as well as historical deposition models; (2) compare the solubility of bioactive trace metals in aerosols and rainwater along with their concentration and distribution in surface water samples versus Al values to assess the role that atmospheric deposition has in controlling/altering the upper ocean biogeochemical cycles of these elements; (3) ascertain the magnitude and pathways via which atmospheric inputs get incorporated into the thermocline and central waters of the North Pacific; and (4) provide baseline concentrations for trace metals. The PIs will collect surface samples while underway by pumping water onto the ship through a Teflon-lined, polyethylene tube mounted on a modified bathythermograph and vertical profiles at 8 stations that will encompass the key hydrographic regimes of the area. Samples (total, particulate, dissolved, colloidal) will be analyzed for the metals Ag, Al, Cd, Cu, Co, Fe, Mn, Ni, Pb, Zn and the metalloids As, Sb, Se. Aerosols and rainfall samples also will be collected and analyzed for metals/major ions and metals/metalloids, respectively. In addition, selected samples also will be analyzed for nutrients, salinity, oxygen, chlorophyll a, particulate organic carbon, particulate organic nitrogen, particulate organic sulfur, dissolved organic carbon and dissolved organic nitrogen.