Lead-210 and Polonium-210 Across the Frontal Region between the Kuroshio and the East China Sea, Northeast of Taiwan

臺灣東北部黑潮與東海交界鋒面鉛—210，釙—210之研究

楊肇岳(Chao-Yeuh Yang) ； 林慧菁(Hui-Ching Lin)

《Terrestrial, Atmospheric and Oceanic Sciences》 3卷3期 (1992/09) Pp. 379-394

摘要

吾人測量幾個“黑潮邊緣交換過程”大型計劃測站的鉛-210和釙-210的垂直剖面。在B橫斷陸棚路線測站的表水中，鉛-210和釙-210的活性有由淺水站往深水站漸增的趨勢，這反應了在陸棚水中的鉛-210和釙-210被較有效率的清除。而4531，5131的深水站垂直剖面確顯示在上層水（深度小於100米）釙-210係缺乏，釙-210比鉛-210小於1，而在中層水釙-210係超量（深度200米至500米）。以簡單的盒子模式計算，可求出由表層去除的釙-210有85.4％在中層水中釋放而再循環，鉛-210則僅有2.9％再循環。512A站近陸棚邊緣斷崖，時有湧升或入侵的黑潮水，造成此站釙—210活性富集。5323站位於大陸棚坡上端，極為陡峭，此站鉛—210在整個水柱中均較釙-210過量，係由帶過量的鉛-210沉積顆粒由陸棚外緣往棚坡水域輸送之結果。陸棚淺水站則可見大部份水柱中，釙-21O係過量，僅表面上層（深度小於20米）除外。

並列摘要

Concentration profiles of Pb-210, Po-210 were measured on several KEEP (Kuroshio Edge Exchange Process) program stations. Results of both Pb-210 and Po-210 of surface water along B transect (from station 6115 to station 4531) showed an increasing trend toward deeper water. This reflected the more efficient removal of Pb-210, Po-210 from the shelf water. Vertical profiles of deep water station (i.e. 4531, 5131) did show Po-210 deficiencies, Po-210/Pb-210＜1, at upper layer (＜100m); and Po-210 excess in the middle layer (200m-500m).
With Box Model calculation, the recycling efficiency of Pb-210 and Po-210 in the middle laycr is found to bc 2.9% and 85.4%. Vcrtical profilc of the near shelf-break station 512Am where upwelling of intrusion of Kuroshio water occurred, showed the feature of richness in Po-210. the profile of the station 5323, located at a very steep upper slope region, showed the feature of Pb-210 excess all over the water column. Some sediment particles shich contains excess Pb-210 might re-export from the outer shelf to slope water. The shelf water station was characterized with Po-210 excess in most of the water column except the very top layer (＜20m).