Publication Date:
2014-08-12
Description:
Climate warming is expected to reduce oxygen (O2) supply to the ocean and expand its oxygen minimum zones (OMZs). We reconstructed variations in the extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification (delta(15)N) from multiple sediment cores. Increasing delta(15)N since ~1990 records an expansion of anoxia, consistent with observed O2 trends. However, this was preceded by a longer declining delta(15)N trend that implies that the anoxic zone was shrinking for most of the 20th century. Both periods can be explained by changes in winds over the tropical Pacific that drive upwelling, biological productivity, and O2 demand within the OMZ. If equatorial Pacific winds resume their predicted weakening trend, the ocean's largest anoxic zone will contract despite a global O2 decline.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Deutsch, Curtis -- Berelson, William -- Thunell, Robert -- Weber, Thomas -- Tems, Caitlin -- McManus, James -- Crusius, John -- Ito, Taka -- Baumgartner, Timothy -- Ferreira, Vicente -- Mey, Jacob -- van Geen, Alexander -- New York, N.Y. -- Science. 2014 Aug 8;345(6197):665-8. doi: 10.1126/science.1252332.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Oceanography, University of Washington, Seattle, WA, USA. cdeutsch@uw.edu. ; Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA. ; Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC, USA. ; School of Oceanography, University of Washington, Seattle, WA, USA. ; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA. ; U.S. Geological Survey, University of Washington School of Oceanography, Seattle, WA, USA. ; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA. ; Departamento de Oceanografia Biologica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Baja California, Mexico. ; Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA. Department of Physical Sciences, Kingsborough Community College, City University of New York, New York, NY, USA. ; Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25104384" target="_blank"〉PubMed〈/a〉
Keywords:
Anaerobiosis
;
Denitrification
;
*Global Warming
;
Oxygen/*analysis
;
Pacific Ocean
;
Seawater/*chemistry
;
*Tropical Climate
;
*Wind
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
