COLLABORATIVE RESEARCH: EVALUATING DEEP-SEA VENTILATION AND THE GLOBAL CARBON CYCLE DURING EARLY PALEOGENE HYPERTHERMALS

GSTDTAP

项目编号	1536630
	COLLABORATIVE RESEARCH: EVALUATING DEEP-SEA VENTILATION AND THE GLOBAL CARBON CYCLE DURING EARLY PALEOGENE HYPERTHERMALS
	Arne Winguth
主持机构	University of Texas at Arlington
项目开始年	2015
	2015-08-15
项目结束日期	2018-07-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	403114(USD)
国家	美国
语种	英语
英文摘要	Rapid, short-term global warming events in the Early Paleogene (~65-45 Million years ago) were caused by massive greenhouse gas release into the ocean-atmosphere system. These warming events, called "hyper thermals", had far-reaching effects on the evolution of life on Earth, ecosystems, and the carbon cycle. The most extreme of these events was the Paleocene-Eocene Thermal Maximum (~55.5 Million years ago). Hyperthermals resemble what could happen during anthropogenic climate change, and provide analogs for the effects of greenhouse gas emissions and their long-term effects on life on Earth. By testing earth system interactions during the Paleogene hyperthermals, this interdisciplinary project will provide new insight into global climate-carbon cycle feedbacks and extremes in climate. The research will serve the national interest by improving a widely used Community Earth System Model on high-performance computers, and by synthesizing data and model output with observations from novel isotopic and trace element techniques in marine geology and paleoceanography. Multidisciplinary research and educational activities are integrated and will lead to development and widespread circulation of educational materials on abrupt climate change, thus enhancing training in quantitative science for undergraduate and high school students from diverse backgrounds. Specifically, this collaborative effort involves integration of new biotic, isotopic and trace element proxies with existing data into a state-of-the-art, high-resolution, comprehensive earth system model to test the hypothesis that deep-sea ventilation released a massive amount of carbon from the refractory dissolved organic matter (DOM) pool during hyperthermal events, increasing atmospheric CO2 levels, and thus amplifying climate change through carbon-cycle feedback. The research team will investigate the environmental response (e.g., ocean acidification and deoxygenation) and its impact on pelagic ecosystem structure for three Paleogene hyperthermals with different magnitudes and durations. The project will focus on a key mechanism involving remineralization of organic matter and oxidation of the DOM pool in the ocean, with potentially major implications for future climate evolution, addressing these questions: (1) How might changes in oceanic productivity, organic carbon remineralization, ocean oxygenation, and export efficiency during hyperthermals have contributed to changes in the oceanic dissolved organic matter reservoir? (2) Could DOM release due to enhanced ocean ventilation have been at least a partial cause of Paleogene hyperthermals? (3) What are the implications of Paleogene climate?carbon cycle changes associated with DOM storage and release for future extremes in climate and the environment? New data on planktic and benthic foraminifera, and accumulation of marine barite on the same samples will be obtained and integrated with a large amount of existing data to provide insight into ecosystem-dependent export productivity and remineralization, as well as regionally varying vertical carbon fluxes. Recently gathered data from the equatorial regions will be incorporated in a database to provide initial conditions for the earth system model. The model results will give insight into changes in ocean stratification, vertical carbon gradients, DOM reservoirs, oxygenation, and ecosystem composition during transitions into and out of hyperthermals. In particular, the team will evaluate the possibility of extreme changes in response to ecosystem-related fluctuations in DOM accumulation and subsequent oxidation and emission from the oceans, because the DOM pool is the largest reservoir of easily interchangeable carbon. This mechanism has not been thoroughly explored as a contributor to a transition into a hothouse climate with more extreme weather patterns.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68492
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Arne Winguth.COLLABORATIVE RESEARCH: EVALUATING DEEP-SEA VENTILATION AND THE GLOBAL CARBON CYCLE DURING EARLY PALEOGENE HYPERTHERMALS.2015.