| 摘要: |
| 基于2020年1—12月在赤道印度洋中部海域获取的沉积物捕获器时间序列样品，分析了沉降颗粒物与颗粒有机碳（particulate organic carbon， POC）通量的季节变化特征，并结合卫星遥感、数值模式及再分析数据探究上层物理过程对生物泵输出通量的调控作用。结果表明，2020年赤道印度洋中部海域的沉降颗粒物总通量与颗粒有机碳通量的变化范围分别为4.57~35.75 mg/(m2·d)\[(18.94±10.18) mg/(m2·d)\]和0.27~2.97 mg/(m2·d)\[(1.09±0.66) mg/(m2·d)\]，两者均呈现显著的季节变化特征。总体上，1—3月、6月和9—11月呈现出3个显著的高通量事件。通过分析发现混合层深度变化与营养盐跃层波动的耦合作用可能是调控中深层通量变化的主要原因。与此同时，西南季风流（Southwest Monsoon Current， SMC）与赤道Wyrtki急流生消也可能通过改变温跃层或营养盐跃层深度对沉降颗粒物通量强度和季节变化起调控作用。 |
| 关键词: 海洋化学 沉降颗粒物 沉积物捕获器 混合层 温跃层 赤道印度洋 |
| DOI：10.3969/J.ISSN.2095-4972.20230607001 |
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| 基金项目:全球变化与海气相互作用专项II(GASI-04-HYST-01，GASI-01-EIND-STwin)；中央级公益性科研院所基本科研业务费专项资金项目(JB2307)；国家自然科学基金(42176039，42206038) |
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| Seasonal variations of sinking particle flux and its regulation mechanism in the central equatorial Indian Ocean |
| YU Jinping,ZHANG Jingjing,LI Hongliang,LU Yangyang,HE Xingju,WU Zezhou,CHEN Jianfang |
| (Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, MNR, Hangzhou 310012, China) |
| Abstract: |
| Based on time series sediment trap samples collected in the southern Sri Lanka of the central equatorial Indian Ocean from January to December 2020, we measured the magnitude of total sinking particle and particulate organic carbon (POC) fluxes, and evaluated the impact of upper ocean physical processes on sinking particle fluxes in combination with remote sensing physical parameters, numerical model and reanalysis data. Results showed significant seasonal variations in total sinking particle and POC fluxes ranged from 4.57 to 35.75 mg/(m2·d)［(18.94 ± 10.18) mg/(m2·d)］ and 0.27 to 2.97 mg/(m2·d)［(1.09 ± 0.66) mg/(m2·d)］, respectively. Overall, three discrete high-flux events occurred in periods of January to March, June and September to November. The coupling regulation of surface mixing and thermocline fluctuation was supposed to responsible for the variability in fluxes. While the development of Southwest Monsoon Current and equatorial Wyrtki Jet may also depress the biological carbon pump due to the deepening effect on the thermocline/nutricline depth. |
| Key words: marine chemistry sinking particle sediment trap mixed layer thermocline equatorial Indian Ocean |
