Oceanic controls on the primary production of the northwest European continental shelf: model experiments under recent past conditions and a potential future scenario


Autoria(s): Holt, JT; Butenschon, M; Wakelin, SL; Artioli, Y; Allen, JI
Data(s)

01/01/2012

Resumo

In this paper we clearly demonstrate that changes in oceanic nutrients are a first order factor in determining changes in the primary production of the northwest European continental shelf on time scales of 5–10 yr. We present a series of coupled hydrodynamic ecosystem modelling simulations, using the POLCOMS-ERSEM system. These are forced by both reanalysis data and a single example of a coupled ocean-atmosphere general circulation model (OA-GCM) representative of possible conditions in 2080–2100 under an SRES A1B emissions scenario, along with the corresponding present day control. The OA-GCM forced simulations show a substantial reduction in surface nutrients in the open-ocean regions of the model domain, comparing future and present day time-slices. This arises from a large increase in oceanic stratification. Tracer transport experiments identify a substantial fraction of on-shelf water originates from the open-ocean region to the south of the domain, where this increase is largest, and indeed the on-shelf nutrient and primary production are reduced as this water is transported on-shelf. This relationship is confirmed quantitatively by comparing changes in winter nitrate with total annual nitrate uptake. The reduction in primary production by the reduced nutrient transport is mitigated by on-shelf processes relating to temperature, stratification (length of growing season) and recycling. Regions less exposed to ocean-shelf exchange in this model (Celtic Sea, Irish Sea, English Channel, and Southern North Sea) show a modest increase in primary production (of 5–10%) compared with a decrease of 0–20% in the outer shelf, Central and Northern North Sea. These findings are backed up by a boundary condition perturbation experiment and a simple mixing model.

Formato

text

Identificador

http://plymsea.ac.uk/5284/1/Holt%20et%20al%20Biogeosciences%202012.pdf

Holt, JT; Butenschon, M; Wakelin, SL; Artioli, Y; Allen, JI. 2012 Oceanic controls on the primary production of the northwest European continental shelf: model experiments under recent past conditions and a potential future scenario. Biogeosciences, 9. 97 - 117. 10.5194/bg-9-97-2012 <http://doi.org/10.5194/bg-9-97-2012>

Idioma(s)

en

Relação

http://plymsea.ac.uk/5284/

http://dx.doi.org/10.5194/bg-9-97-2012

doi:10.5194/bg-9-97-2012

Palavras-Chave #Computer Science #Data and Information #Ecology and Environment #Marine Sciences #Oceanography
Tipo

Publication - Article

PeerReviewed