| 摘要: |
| 边缘海初级生产力普遍较高,有机碳在沉积物中的埋藏高达全球的80%。黄渤海是位于我国东部的一个半封闭的温带陆架边缘海,在近20年中,黄渤海经历的台风事件频率不断增大,对碳循环关键过程发生多重影响。文章利用多组卫星及再分析资料,围绕2003~2020年期间夏季台风过境对黄渤海关键环境变量的影响,分析生物和非生物过程对不同海域水体中颗粒有机碳的贡献。结果表明,夏季台风过境一次、两次对黄渤海叶绿素的影响没有明显差异,叶绿素浓度增加主要在渤海西南部和南黄海约50%的海域。总体上看,台风过境对渤海、北黄海大部分海域水体中颗粒有机碳影响不大,但两次台风过境引起了南黄海约80%的离岸海域颗粒有机碳浓度的显著增加。南黄海中部海域水体中颗粒有机碳与叶绿素的比值在台风过后明显降低,表明该海域颗粒有机碳浓度的提高主要是由生物固碳过程的增强引起。台风过境加剧了黄海与渤海、近岸与离岸的水流交换,此过程增强了高营养盐和有机物水向南黄海尤其是中部海域的输送,因而提高了南黄海大部分海域颗粒有机碳浓度。除了光合作用等生物过程及水流交换对颗粒有机碳有影响外,黄渤海水体中颗粒有机碳浓度还受到沉积物再悬浮、陆源有机碳输入等过程的影响。台风过境可以加剧沉积物再悬浮和陆源有机物的输入,进一步提高黄渤海近岸及离岸海域颗粒有机碳的浓度。 |
| 关键词: 叶绿素 颗粒有机碳 季节变化 台风事件 黄渤海 |
| DOI：10.11693/hyhz20211200328 |
| 分类号:P734 |
| 基金项目:NSFC-山东联合重点基金,U1806227号。 |
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| IMPACTS OF TYPHOON EVENTS ON THE SEASONAL VARIATION OF PARTICULATE ORGANIC CARBON IN THE YELLOW-BOHAI SEA IN THE PAST TWO DECADES |
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WANG Xiu-Jun1, WANG Xiao-Wen1, YOU Zai-Jin2,3, SHI Hong-Yuan3
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1.College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China;2.College of Transportation Engineering, Dalian Maritime University, Dalian 315100, China;3.Centre for Ports and Coastal Disaster Mitigation, Ludong University, Yantai 264025, China
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| Abstract: |
| Typhoon events have large impacts on marginal seas’ environmental conditions with implications for carbon cycling. However, little is known about the responses of particulate organic carbon (POC) to typhoon events in the Yellow-Bohai Sea (YBS). In this study, we utilized satellite-derived datasets of chlorophyll (chl) and POC, together with key physical parameters, to analyze their responses to the typhoon events during 2003~2020. In the past 18 years, there were 6 years experiencing 1 typhoon event and another 6 years having 2 typhoons, between June and October with weakened wind (lower than category 3 in intensity) and heavy rainfall. Result shows that Chl-a was increased in summer of typhoon years in the western Bohai Sea (BS) and western/central South Yellow Sea (SYS), especially in the upper layer of Yellow Sea Cold Water Mass, but decreased in most parts of the North Yellow Sea (NYS). POC is increased in the western/central SYS (by ~50%) and decreased in the BS and most parts of the NYS. In addition, POC/chl ratio was decreased in the BS and central SYS in typhoon years, indicating that elevated POC was largely resulted from enhanced phytoplankton growth. Some coastal regions in the YBS showed an increase in POC/chl ratio, suggesting that there were other POC sources rather than biological contribution, such as sediment resuspension and terrestrial runoff. This study highlights the complex impacts of typhoon on the carbon cycle in marginal seas. |
| Key words: chlorophyll particulate organic carbon seasonal variation typhoon events Yellow-Bohai Sea |
