NICOPP - Nitrogen Cycle in the Ocean, Past and Present
Major sources (green arrows) and sinks (white arrows) of fixed N in the marine environment and their most important controlling factors over time (italics). From Galbraith et al., 2008, Nitrogen in Past Marine Environments, in: Capone et al. (Eds) Nitrogen in the Marine Environment, 1497-1535.
NICOPP is a joint working group of PAGES and IMAGES. NICOPP studies Nitrogen isotope (d15N) dynamics as recorded in the sedimentary record in order to learn about the dynamics of the marine nutrient cycle in the Quaternary and the present.
Marine nutrient cycling is a globally important biogeochemical process that, if perturbed, can shift carbon and nutrient budgets significantly within the Earth System, with immediate implications for global climate. However, projections for the coming decades disagree even on the sign of the cumulative climatic feedback of marine nutrient cycling and associated biological changes.
If we wish to be able to meaningfully assess the potential impact of marine nutrient cycling on ecosystems and atmospheric composition, and ultimately the feedbacks with the climate system, we need to better understand the processes and effects involved. The large oceanographic and biogeochemical changes that occurred during the last glacial cycle provide pronounced and accessible targets for paleoceanographic studies (reconstruction and modeling) of marine nutrient cycles.
Nitrogen cycling is considered to be a dominant component of the marine biogeochemistry, and is the focus of this working group. With nitrogen isotopes there is a paleo-oceanographic proxy that seems well understood and frequently applied.
Accordingly, NICOPP aims to compile a quantitative global synopsis of the d15N data, to reveal patterns of nitrogen cycling processes, such as N-fixation, denitrification, and nitrate utilization, and to synthesize the findings and implications.
NICOPP brings together international colleagues active in marine N-isotope research as applied to the past ocean, and carries out activities such as workshops aimed at synthesizing currently available paleo data and publishing review papers.
Specifically, NICOPP has four goals:
1) Compilation, mapping and synthesis of modern (surface sediment) sedimentary d15N variability, and comparison of this data set to modern oceanographic and biogeochemical parameters and modeling. This will further and refine our understanding of this proxy.
2) Compilation and synthesis of sedimentary d15N records covering the last glacial-interglacial cycle (last 150,000 years) with the aim of defining regionally (or globally) consistent patterns and trends.
3) Comparison of the modern, surface sediment d15N variations to the sedimentary d15N distribution during past time periods, e.g. the Last Glacial Maximum (following MARGO approaches and criteria).
4) Comparing results from biogeochemical ocean modeling with the new quantitative synthesis of sedimentary d15N records.
The NICOPP working group is comprised of scientists who have attended NICOPP workshops and/or co-authored a NICOPP paper. It is generally open to all interested scientists who are willing to share their data.
Images below, R-L: 2010 NICOPP workshop in Montreal / 2011 NICOPP workshop in Halifax
Working group participants
Albuquerque, Ana Luiza
Calvert, Stephen E.
Contreras, Quintana Sergio
De Pol Holz, Ricardo
Hsu, Leon Ting-Chang
Lehmann, Moritz F.
Meckler, Anna Nele
Studer, Anja S.
Van Geen, Lex
Yang, Jin-Yu Terence
- NICOPP 2: Sedimentary d15N - data synthesis, analysis and modeling
Dalhousie University, Halifax, Canada // 2011-07-08
- AGU Fall Meeting 2010
San Francisco, California, USA // 2010-12-13
- NICOPP: Sedimentary d15N - surface sediment distribution and records of Quaternary variability
McGill University, Montreal, Canada // 2010-05-14
The acceleration of oceanic denitrification during deglacial warming
Eric D. Galbraith and Markus Kienast et al.
Nature Geoscience, 6, 579–584 (2013)
Nitrogen isotopes in bulk marine sediment: Linking seafloor observations with subseafloor records
J. E. Tesdal, E. D. Galbraith, and M. Kienast
Biogeosciences, 10, 101-118 (2013)
A review of nitrogen isotopic alteration in marine sediments
Robinson et al.
Paleoceanography, 27(4), (2012)