Arabian Sea Denitrification Data Altabet, M.A.; Higginson, M.J.; Murray, D.W. Altabet, M.A. Higginson, M.J. Murray, D.W. earth science/paleoclimate/paleoceanography (nitrogen,sediment,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,null,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (chlorin,sediment,null,microgram per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,radiocarbon year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (RC27-14>LATITUDE 18.25>LONGITUDE 57.65) (RC27-23>LATITUDE 18>LONGITUDE 57.58) Most global biogeochemical processes are known to respond to climate change, some of which have the capacity to produce feedbacks through the regulation of atmospheric greenhouse gases. Marine denitrification-the reduction of nitrate to gaseous nitrogen-is an important process in this regard, affecting greenhouse gas concentrations directly through the incidental production of nitrous oxide, and indirectly through modification of the marine nitrogen inventory and hence the biological pump for CO2. Although denitrification has been shown to vary with glacial-interglacial cycles, its response to more rapid climate change has not yet been well characterized. Here we present nitrogen isotope ratio, nitrogen content and chlorin abundance data from sediment cores with high accumulation rates on the Oman continental margin that reveal substantial millennial-scale variability in Arabian Sea denitrification and productivity during the last glacial period. The detailed correspondence of these changes with Dansgaard-Oeschger events recorded in Greenland ice cores indicates rapid, century-scale reorganization of the Arabian Sea ecosystem in response to climate excursions, mediated through the intensity of summer monsoonal upwelling. Considering the several-thousand-year residence time of fixed nitrogen in the ocean, the response of global marine productivity to changes in denitrification would have occurred at lower frequency and appears to be related to climatic and atmospheric CO2 oscillations observed in Antarctic ice cores between 20 and 60 kyr ago. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Altabet, M.A. Investigator : Higginson, M.J. Investigator : Murray, D.W. 2002-07-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/2617 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-14-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-23-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/altabet2002 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-14-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-23-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/altabet2002 English https://www.ncdc.noaa.gov/paleo/study/2617 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-14-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/rc27-23-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/altabet2002 Altabet, M.A., M.J. Higginson, and D.W. Murray. 2002. The effect of millennial-scale changes in Arabian Sea denitrification on atmospheric CO2. Nature 415:159-162. START YEAR: 63578 14C yr BP * END YEAR: 130 14C yr BP 57.58 18 57.65 18.25