气候变化领域集成服务门户(CCPortal): Self-Shading and Meltwater Spreading Control the Transition From Light to Iron Limitation in an Antarctic Coastal Polynya

CCPortal

DOI	10.1029/2020JC016636
	Self-Shading and Meltwater Spreading Control the Transition From Light to Iron Limitation in an Antarctic Coastal Polynya
	Twelves A.G.; Goldberg D.N.; Henley S.F.; Mazloff M.R.; Jones D.C.
发表日期	2021
ISSN	21699275
卷号	126 期号:2
英文摘要	Dotson Ice Shelf (DIS) in West Antarctica is undergoing rapid basal melting driven by intrusions of warm, saline Circumpolar Deep Water (CDW) onto the continental shelf. Meltwater from DIS is thought to influence biology in the adjacent Amundsen Sea Polynya (ASP), which exhibits the highest net primary productivity (NPP) per unit area of any coastal polynya in the Southern Ocean. However, the relative importance of iron and light in colimiting the spring phytoplankton bloom in the ASP remains poorly understood. In this modeling study we first investigate the mechanisms by which ice shelves impact NPP, then map spatio-temporal patterns in iron-light colimitation, and finally examine the environmental drivers of iron and light supply. We find that ice shelf melting leads to greater upper ocean iron concentrations, both directly due to release of iron from sediments entrained at the glacier bed, and indirectly via a buoyancy-driven overturning circulation which pulls iron from CDW to the surface. Both of these mechanisms increase NPP compared to experiments where ice shelf melt is suppressed. We then show that the phytoplankton self-shading feedback delays the bloom and reduces peak NPP by 80% compared to experiments where light penetration is independent of chlorophyll. Compared to light limitation, iron limitation due to phytoplankton uptake is more important a) later in the season, b) higher in the water column, and c) further from the ice shelf. Finally, sensitivity experiments show that variability in CDW intrusion influences NPP by controlling the horizontal spreading of iron-rich meltwater. © 2020. The Authors.
英文关键词	Amundsen Sea; colimitation; meltwater; NPP; phytoplankton; self-shading
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186460
作者单位	School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom; Scripps Institute of Oceanography, La Jolla, CA, United States; British Antarctic Survey, NERC, UKRI, Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Twelves A.G.,Goldberg D.N.,Henley S.F.,et al. Self-Shading and Meltwater Spreading Control the Transition From Light to Iron Limitation in an Antarctic Coastal Polynya[J],2021,126(2).
APA	Twelves A.G.,Goldberg D.N.,Henley S.F.,Mazloff M.R.,&Jones D.C..(2021).Self-Shading and Meltwater Spreading Control the Transition From Light to Iron Limitation in an Antarctic Coastal Polynya.Journal of Geophysical Research: Oceans,126(2).
MLA	Twelves A.G.,et al."Self-Shading and Meltwater Spreading Control the Transition From Light to Iron Limitation in an Antarctic Coastal Polynya".Journal of Geophysical Research: Oceans 126.2(2021).