Radioisotope Studies to Understand Biogeochemical Processes and Particle Dynamics in the Equatorial Pacific

通过放射性同位素研究了解赤道太平洋的生物地球化学过程和粒子动力学

• 批准号: 9022373
• 负责人: Teh-Lung Ku
• 金额: $ 46.52万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-06-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9022373&HistoricalAwards=false
• 关键词: Radioisotope; Studies; Understand; Biogeochemical; Processes

As part of the U.S. Joint Global Ocean Flux Studies (JGOFS) in the central equatorial Pacific, the proposed research is a study of the upper water-column distribution of naturally occurring uranium and thorium decay series nuclides and cosmogenic isotopes of beryllium along a N-S transect across the Equator. The radioisotopes are used as tracers to gather information about the rates of biogeochemical processes that influence the scavenging of chemical species and the behavior/fate of biogenic particles in the sea. Specifically, the data obtained from the distribution of 228Ra and 10Be- normalized 7Be activities, coupled with those of nitrate and dissolved carbon, will enable us to estimate the vertical flux of nitrate and new production at various levels in the surface ocean. By measuring the specific activities of 234Th, 230Th, 228Th, 210Pb, 210PO and 7Be/10Be in the dissolved the P.I:s' will evaluate the forward and backward exchange rate constants for reactions involving dissolved small suspended particulate large settling particulate in three depth zones of the surface ocean, and the scavenging residence time of large particulates in the euphotic zone. It is anticipated that the study will enhance our understanding of the upper ocean biogeochemical dynamics and cycling in the equatorial Pacific, an area thought to play an important role in global carbon fluxes.

作为美国联合全球海洋通量研究的一部分， 中赤道太平洋，拟议的研究是一个 天然气库上层水柱分布研究 发生铀和钍衰变系列核素， 沿着南北向断面的铍的宇宙成因同位素 赤道 放射性同位素被用作示踪剂， 关于地球化学过程速率的信息， 影响化学物质的清除， 海洋中生物颗粒的行为/命运。 具体地说， 从~（228）Ra和~（10）Be- 标准化的7 Be活动，再加上硝酸盐和 溶解的碳，将使我们能够估计垂直通量 硝酸盐和新的生产在不同层次的表面 海洋 通过测定234 Th、230 Th、 228 Th、210 Pb、210 PO和7 Be/10 Be在溶解的P.I：s' 将评估前向和后向汇率常数 对于涉及溶解的小悬浮颗粒的反应 在表面的三个深度区域中的大的沉降颗粒 海洋，以及大颗粒的清除停留时间 在透光层。 预计这项研究将 提高我们对海洋上层地球化学的认识 赤道太平洋的动力学和循环， 在全球碳通量中扮演重要角色。