摘要:
为了研究黄海生物泵过程，2009 年夏季利用234Th 示踪法对黄海进行了颗粒有机碳输出通量的研究。以小体积海水 MnO2共沉淀-β 计数法测定海水中总态及颗粒态234Th 的活度，在上层水柱中颗粒态及总态234Th活度显著低于母体238U 的活度。基于上层水体中234Th:238U 的不平衡并结合一维稳态不可逆清除模型，估算出从真光层底部输出的 POC 通量。夏季黄海颗粒有机碳的输出通量变化范围为 12.7 ± 1.7~92.0 ± 21.0 mmol C m−2·d−1,平均值为 45.3 ± 41.5 mmol C m−2·d−1 (n = 3, ±1SD)。 本研究结果为进一步厘清黄海在全球碳循环的作用提供了参考。
Abstract: 234Th was utilized as a tracer of particulate organic carbon (POC) fluxes from the euphotic zone to study biological pump process in the Yellow Sea in the summer of 2009. 234Th in the upper water column was determined by using a modified small-volume MnO2 co-precipitation technique, and its deficit with respect to 238U was found to be evident throughout the upper water column. The 234Th:238U disequilibrium in the upper waters and one-dimensional irreversible steady state model were used to calculate the POC export fluxes from the bottom of euphotic layer. The POC export flux varied from 12.7 ± 1.7 mmol C m−2·d−1 to 92.0 ± 21.0 mmol C m−2·d−1, with an average of 45.3 ± 41.5 mmol C m−2·d−1 (n = 3, ±1SD). The results will provide a better understanding of the role that the Yellow Sea plays in the global carbon cycle.