Bubbles Transport Massive Amounts of Oxygen to the Deep Ocean through Marine ‘Trap Door’

Scripps Oceanography study co-authors Jannes Koelling (left) and Uwe Send

“The SeaCycler was designed to collect sophisticated profiling measurements and carry a very large payload under extreme, very difficult conditions. You really don’t want to be out in the Labrador Sea on a ship, making measurements yourself in winter when these bubble processes are most important,” said Uwe Send of Scripps Oceanography who was also the driving force behind SeaCycler’s development, working closely with engineers at Canada’s Bedford Institute of Oceanography.

Send and his student Jannes Koelling are the two Scripps Oceanography co-authors of the study.

Understanding how much oxygen is transferred is important because deep ocean waters flow out of the Labrador Sea and supply oxygen to a vast area of the ocean, worldwide.

“We often refer to the Labrador Sea as being one of the lungs of the deep ocean and the deep circulation as being like a blood stream,” said Atamanchuk.

Previous research has suggested that the Labrador Sea’s trap door might be closing, mainly due to increasing amounts of fresh water from melting ice on Greenland and the rapidly changing Arctic. “More fresh water means shallower mixing and that would cause the ocean’s breathing to, literally, become shallower,” said Doug Wallace, an oceanographer at Dalhousie who initiated the study.

Atamanchuk added that the effect of closing a similar trap door off Antarctica may already have been felt in the deep South Atlantic Ocean, which has recorded high and otherwise difficult-to-explain levels of deoxygenation over the past 50 years.

“While the details of transfer by bubbles are not fully understood, our measurements show clearly that they deliver massive amounts of gases such as oxygen to the deep sea when the trap door opens around December,” said Wallace. “The importance of this bubble-mediated transfer may have been overlooked and our finding definitely justifies more observation and study in extreme locations like the Labrador Sea.”

The Natural Sciences and Engineering Research Council of Canada; Canada Excellence Research Chair in Ocean Science and Technology; Government of Canada (Canada Excellence Research Chairs Program); National Aeronautics and Space Administration (NASA); National Science Foundation funded the research.

– Adapted from Dalhousie University

	Bubbles Transport Massive Amounts of Oxygen to the Deep Ocean through Marine ‘Trap Door’
	admin
	2020-02-03
发布年	2020
语种	英语
国家	美国
领域	资源环境
正文(英文)	Crew deploys the SeaCycler on May 22, 2016 for year-long measurements in the central Labrador Sea. Photo: Kat Fupsova Much more oxygen than previously thought is being transported into deep layers of the ocean through a ‘trap door’ off Canada’s Atlantic coast, that some researchers say could be closing as a result of climate change. Scientists from Dalhousie University in Halifax, Nova Scotia, and Scripps Institution of Oceanography at the University of California San Diego measured the higher-than-expected transfer of oxygen from the atmosphere to depths as great as two kilometers (1.2 miles) in the Labrador Sea, attributing it to the injection of air bubbles during winter storms. The transfer happens at the same time as surface water becomes cold and dense enough to trigger mixing with deep, oxygen-deficient waters. This “trap door” connecting the atmosphere with the deep ocean opens for only a few months each year and the Labrador Sea is one of only a handful of regions in the world where it occurs. “While bubble-mediated gas transfer has been recognised for decades, we have shown how critically important it is when the trap door is open, exposing a vast volume of oxygen-deficient deep ocean water to the atmosphere,” said Dariia Atamanchuk, a research associate in Dalhousie’s Department of Oceanography and the lead author of the study. The researchers estimate that 10 times more oxygen is transferred to the deep sea each year compared to models that typically do not account for bubbles. This implies that oxygen in the deep ocean may be more sensitive to climate change than previously thought. The scientists were working as part of a Canadian-led project called VITALS (Ventilation and Interactions Across the Labrador Sea) and outlined their findings in a paper published today in Nature Geoscience. The researchers gathered the information using SeaCycler, a unique, robotic profiling system that was anchored in the Labrador Sea in 2016 and collected a wide range of chemical, physical and biological data. “The SeaCycler was designed to collect sophisticated profiling measurements and carry a very large payload under extreme, very difficult conditions. You really don’t want to be out in the Labrador Sea on a ship, making measurements yourself in winter when these bubble processes are most important,” said Uwe Send of Scripps Oceanography who was also the driving force behind SeaCycler’s development, working closely with engineers at Canada’s Bedford Institute of Oceanography. Send and his student Jannes Koelling are the two Scripps Oceanography co-authors of the study. Understanding how much oxygen is transferred is important because deep ocean waters flow out of the Labrador Sea and supply oxygen to a vast area of the ocean, worldwide. “We often refer to the Labrador Sea as being one of the lungs of the deep ocean and the deep circulation as being like a blood stream,” said Atamanchuk. Previous research has suggested that the Labrador Sea’s trap door might be closing, mainly due to increasing amounts of fresh water from melting ice on Greenland and the rapidly changing Arctic. “More fresh water means shallower mixing and that would cause the ocean’s breathing to, literally, become shallower,” said Doug Wallace, an oceanographer at Dalhousie who initiated the study. Atamanchuk added that the effect of closing a similar trap door off Antarctica may already have been felt in the deep South Atlantic Ocean, which has recorded high and otherwise difficult-to-explain levels of deoxygenation over the past 50 years. “While the details of transfer by bubbles are not fully understood, our measurements show clearly that they deliver massive amounts of gases such as oxygen to the deep sea when the trap door opens around December,” said Wallace. “The importance of this bubble-mediated transfer may have been overlooked and our finding definitely justifies more observation and study in extreme locations like the Labrador Sea.” The Natural Sciences and Engineering Research Council of Canada; Canada Excellence Research Chair in Ocean Science and Technology; Government of Canada (Canada Excellence Research Chairs Program); National Aeronautics and Space Administration (NASA); National Science Foundation funded the research. – Adapted from Dalhousie University Note to broadcast and cable producers: University of California San Diego provides an on-campus satellite uplink facility for live or pre-recorded television interviews. Please phone or email the media contact listed above to arrange an interview. About Scripps OceanographyScripps Institution of Oceanography at the University of California San Diego, is one of the oldest, largest, and most important centers for global science research and education in the world. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical, and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today on every continent and in every ocean. The institution has a staff of more than 1,400 and annual expenditures of approximately $195 million from federal, state, and private sources. Scripps operates oceanographic research vessels recognized worldwide for their outstanding capabilities. Equipped with innovative instruments for ocean exploration, these ships constitute mobile laboratories and observatories that serve students and researchers from institutions throughout the world. Birch Aquarium at Scripps serves as the interpretive center of the institution and showcases Scripps research and a diverse array of marine life through exhibits and programming for more than 430,000 visitors each year. Learn more at scripps.ucsd.edu and follow us at Facebook, Twitter, and Instagram.About UC San DiegoAt the University of California San Diego, we embrace a culture of exploration and experimentation. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren’t afraid to look deeper, challenge expectations and redefine conventional wisdom. As one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth and make our world a better place. Learn more at www.ucsd.edu.
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来源平台	Scripps Institution of Oceanography
文献类型	新闻
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/227943
专题	资源环境科学
推荐引用方式 GB/T 7714	admin. Bubbles Transport Massive Amounts of Oxygen to the Deep Ocean through Marine ‘Trap Door’. 2020.

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