气候变化领域集成服务门户(CCPortal): Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico

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DOI	10.1029/2020JC016152
	Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico
	Wang H.; Lehrter J.; Maiti K.; Fennel K.; Laurent A.; Rabalais N.; Hussain N.; Li Q.; Chen B.; Scaboo K.M.; Cai W.-J.
发表日期	2020
ISSN	21699275
卷号	125 期号:10
英文摘要	It is known that surface water eutrophication enhances bottom water ocean acidification via respiration in coastal oceans. However, the role of benthic processes in influencing bottom water acidification has not been sufficiently explored. We examined this issue by analyzing a 10-year summer carbonate chemistry dataset in bottom water together with recent benthic flux measurements and literature benthic flux data in the northern Gulf of Mexico. The difference between the observed and estimated pH (Ω) values calculated from anthropogenic CO2 increase and water column aerobic respiration were defined as ΔpH (ΔΩ). We found that ΔpH and ΔΩ values in hypoxic condition were −0.03 ± 0.04 (mean ± standard deviation) and −0.15 ± 0.39, respectively. Both ΔpH and ΔΩ values in hypoxic conditions were significantly lower than zero (p < 0.05). The net results of anaerobic respiration, oxidation of reduced chemcials, burial of iron sulfide minerals, and possible CaCO3 dissolution may have led to an alkalinity to DIC production ratio of less than 1 in porewater. This caused the ratio of alkalinity to dissolved inorganic carbon fluxes from sediment to bottom water to be less than 1, which led to additional bottom water acidification. Our analysis and model simulations demonstrate that severe hypoxic and anoxic conditions, which correspond to less water movement, favor the accumulation of benthic respiration products, leading to additional pH and Ω reductions. The findings on sediment processes contributing to acidification in bottom waters provide new insights into the sensitivity of coastal ocean acidification to low-oxygen conditions under current and future climates and anthropogenic nutrient loading scenarios. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	eutrophication; hypoxia; norther Gulf of Mexico; ocean acidification; sediment anaerobic respiration
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/186657
作者单位	School of Marine Science and Policy, University of Delaware, Newark, DE, United States; Department of Marine Sciences, University of South Alabama, Dauphin Island Sea Laboratory, Dauphin Island, AL, United States; Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States; Department of Oceanography, Dalhousie University, Halifax, NS, Canada
推荐引用方式 GB/T 7714	Wang H.,Lehrter J.,Maiti K.,et al. Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico[J],2020,125(10).
APA	Wang H..,Lehrter J..,Maiti K..,Fennel K..,Laurent A..,...&Cai W.-J..(2020).Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico.Journal of Geophysical Research: Oceans,125(10).
MLA	Wang H.,et al."Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico".Journal of Geophysical Research: Oceans 125.10(2020).