A high-resolution study of particle export in the southern South China Sea based on 234Th:238U disequilibrium
A high-resolution study of particle export in the southern South China Sea based on 234Th:238U disequilibrium
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基于234Th:238U不平衡的南海南部颗粒输出高分辨率研究
DOI：
10.1029/2007jc004268
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发表时间：
2008-04
影响因子：
3.6
通讯作者：
蔡平河
中科院分区：
文献类型：
--
作者：
蔡平河
在2004年春季季风期间的巡航中，在南海南部（SCS）的36个站收集了100米以上的总Th-234和颗粒Th-234的深度剖面，覆盖了大约1.0 x 10（6）km（2）的表面积。钍-234采样通过使用修改后的小体积MnO 2共沉淀技术，它允许映射的Th-234分布具有高的空间分辨率。Th-234/U-238不平衡的分层结构在100 m以上的水柱中普遍观察到，表明该季节南海南部的真光层可以分为两层：上层低输出生产率和下层高输出生产率。与此同时，我们观察到广泛的Th-234过剩区的真光层内，这可能是由于强烈的颗粒物质的矿化。颗粒有机碳（POC）的出口估计从三维稳态模型的Th-234通量结合悬浮颗粒的POC/Th-234比的测量。该区域POC输出量从最低的-10.7 +/- 1.5 mmolC m（-2）d（-1）到最高的12.6 +/- 1.1 mmolC m（-2）d（-1）不等，平均值为3.8 +/- 4.0 mmolC m（-2）d（-1）。POC输出的负通量被解释为来自附近沃茨的颗粒物的横向输入的结果。POC输出的区域模式显示，沿研究区域的西部和南部边界沿着的通量增强，低输出的“舌头”向西北方向延伸，从类似于7度N 116度E到类似于10度N 111度E。这一地理分布与南海南部在这一季的总体地面环流格局是一致的。
During a spring intermonsoon cruise in 2004, depth profiles of total and particulate Th-234 in the upper 100 m were collected at 36 stations in the southern South China Sea (SCS), covering a surface area of similar to 1.0 x 10(6) km(2). Thorium-234 was sampled by using a modified small-volume MnO2 co-precipitation technique, which allows mapping the Th-234 distribution with a high spatial resolution. A stratified structure of Th-234/U-238 disequilibria was generally observed in the upper 100 m water column, suggesting that the euphotic zone of the southern SCS in this season can be separated into two layers: an upper layer with low export production rates and a lower layer with high export production rates. At the same time, we observed extensive zones of Th-234 excess within the euphotic layer, which is possibly due to intense remineralization of particulate matter. Particulate organic carbon (POC) export was estimated from a three-dimensional steady state model of Th-234 fluxes combined with measurements of the POC/Th-234 ratio on suspended particles. The POC export for this region varied from a low of -10.7 +/- 1.5 mmolC m(-2) d(-1) to a high of 12.6 +/- 1.1 mmolC m(-2) d(-1), with an average of 3.8 +/- 4.0 mmolC m(-2) d(-1). A negative flux of POC export is interpreted as the result of lateral input of particulate matter from nearby waters. Regional patterns in POC export show enhanced fluxes along the western and southern boundaries of the study region, and a "tongue'' of low export extending northwestward from similar to 7 degrees N 116 degrees E to similar to 10 degrees N 111 degrees E. This geographic distribution is consistent with the overall surface circulation pattern of the southern SCS in this season.
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影响因子：
--
作者：
M. Charette;S. B. Moran;S. Pike;John N. Smith
通讯作者：
M. Charette;S. B. Moran;S. Pike;John N. Smith
影响因子：
5.3
作者：
CHEN, JH;EDWARDS, RL;WASSERBURG, GJ
通讯作者：
WASSERBURG, GJ
影响因子：
4.5
作者：
COALE, KH;BRULAND, KW
通讯作者：
BRULAND, KW
DOI：
10.1016/0967-0645(96)00016-1
发表时间：
1996
影响因子：
3
作者：
M. Bacon;J. Cochran;D. Hirschberg;T. Hammar;A. P. Fleer
通讯作者：
M. Bacon;J. Cochran;D. Hirschberg;T. Hammar;A. P. Fleer
DOI：
10.1016/s0967-0645(00)00075-8
发表时间：
2000-01-01
影响因子：
3
作者：
Cochran, JK;Buesseler, KO;Fleer, A
通讯作者：
Fleer, A