Pichevin et al. 2007 Arabian Sea 50KYr Denitrification Data Pichevin, L.; Bard, E.; Martinez, P.; Billy, I. Pichevin, L. Bard, E. Martinez, P. Billy, I. earth science/paleoclimate/paleoceanography (nitrogen,sediment,null,weight percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,sediment,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (organic carbon,sediment,null,weight percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,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 (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,duplicate of NMR study?) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (MD04-2876>LATITUDE 24.842833>LONGITUDE 64.008167) Modern seawater profiles of oxygen, nitrate deficit, and nitrogen isotopes reveal the spatial decoupling of summer monsoon-related productivity and denitrification maxima in the Arabian Sea (AS) and raise the possibility that winter monsoon and/or ventilation play a crucial role in modulating denitrification in the northeastern AS, both today and through the past. A new high-resolution 50-ka record of δ 15N from the Pakistan margin is compared to five other denitrification records distributed across the AS. This regional comparison unveils the persistence of east-west heterogeneities in denitrification intensity across millennial-scale climate shifts and throughout the Holocene. The oxygen minimum zone (OMZ) experienced east-west swings across Termination I and throughout the Holocene. Probable causes are (1) changes in ventilation due to millennial-scale variations in Antarctic Intermediate Water formation and (2) postglacial reorganization of intermediate circulation in the northeastern AS following sea level rise. Whereas denitrification in the world's OMZs, including the western AS, gradually declined following the deglacial maximum (10-9 ka BP), the northeastern AS record clearly witnesses increasing denitrification from about 8 ka BP. This would have impacted the global Holocene climate through sustained N2O production and marine nitrogen loss. STUDY NOTES: Site is located within the present day Oxygen Minimum Zone (OMZ). NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Pichevin, L. Investigator : Bard, E. Investigator : Martinez, P. Investigator : Billy, I. 2009-12-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/8716 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pichevin2007/pichevin2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/md4-2876-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pichevin2007/pichevin2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/md4-2876-tab.txt English https://www.ncdc.noaa.gov/paleo/study/8716 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pichevin2007/pichevin2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/md4-2876-tab.txt Pichevin, L., E. Bard, P. Martinez, and I. Billy. 2007. Evidence of ventilation changes in the Arabian Sea during the late Quaternary: Implication for denitrification and nitrous oxide emission. Global Biogeochem. Cycles, 21, GB4008. doi: 10.1029/2006GB002852 START YEAR: 49549 cal yr BP * END YEAR: 89 cal yr BP 64.008167 24.842833 64.008167 24.842833