Easterly denitrification signal and nitrogen fixation feedback documented in the western Pacific sediments

Type Article
Date 2011-12
Language English
Author(s) Jia Guodong1, 2, Li Zhiyang2
Affiliation(s) 1 : Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou, Guangdong, Peoples R China.
2 : Chinese Acad Sci, CAS Key Lab Marginal Sea Geol, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China.
Source Geophysical Research Letters (0094-8276) (Amer Geophysical Union), 2011-12 , Vol. 38 , N. 24 / L2460 , P. 1-4
DOI 10.1029/2011GL050021
WOS© Times Cited 20
Abstract A sedimentary delta(15)N record in the equatorial western Pacific (WP) shows glacial-interglacial variability from 6.2 to 11.2 parts per thousand during the last two climatic cycles, similar to the denitrification record in the eastern tropical Pacific (ETP). Contrastively, a record in the South China Sea (SCS) exhibits less changes from 4.4 to 6.4 parts per thousand and is quite alike previously published results in marginal seas in the WP. By ruling out several possible causes for the delta(15)N variability, the delta(15)N record in the equatorial WP is interpreted as the source nitrate delta(15)N signals advected from the ETP. Comparison of several delta(15)N records for the last 25 ka distributed in the WP brings out a pattern of northward decrease in delta(15)N values and variability from the equator to off Mindano and then to marginal seas, supposed to be caused by the northward increase of local N(2) fixation. Therefore, the less glacial-interglacial changes in some delta(15)N records in the WP could imply that the glacial decrease in subsurface delta(15)N due to less denitrification in source waters from the ETP would have been isotopically compensated by a synchronous decrease in local N(2) fixation.
Full Text
File Pages Size Access
Publisher's official version 4 549 KB Open access
Top of the page