Abstract
In the recent past observational and modelling studies have shown that the vertical displacement of water parcels, and therefore, phytoplankton particles in regions of deep-reaching convection plays a key role in late winter/early spring primary production. The underlying mechanism describes how convection cells capture living phytoplankton cells and recurrently expose them to sunlight.This study presents a parameterisation called 'phytoconvection' which focusses on the influence of convection on primary production. This parameterisation was implemented into a three-dimensional physical-biogeochemical model and applied to the Northwestern European Continental Shelf and areas of the adjacent Northeast Atlantic. The simulation was compared to a 'conventional' parameterisation with respect to its influence on phytoplankton concentrations during the annual cycle and its effect on the carbon cycle.The simulation using the new parameterisation showed good agreement with observation data recorded during winter, whereas the reference simulation did not capture the observed phytoplankton concentrations. The new parameterisation had a strong influence on the carbon export through the sinking of particulate organic carbon. The carbon export during late winter/early spring significantly exceeded the export of the reference run.Furthermore, a non-hydrostatic convection model was used to evaluate the major assumption of the presented parameterisation which implies the matching of the mixed layer depth with the convective mixing depth. The applied mixed layer depth criterion principally overestimates the actual convective mixing depth. However, the results showed that this assumption is reasonable during late winter, while indicating a mismatch during spring.
| Language | English |
|---|---|
| Pages | 138-152 |
| Number of pages | 15 |
| Journal | Journal of Marine Systems |
| Volume | 147 |
| Early online date | 11 Jul 2014 |
| DOIs | |
| Publication status | Published - 31 Jul 2015 |
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Keywords
- biogeochemical modelling
- convection
- Northeast Atlantic
- Northwestern European Continental Shelf
- parameterisation
- primary production
Cite this
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The influence of winter convection on primary production : a parameterisation using a hydrostatic three-dimensional biogeochemical model. / Große, Fabian; Lindemann, Christian; Pätsch, Johannes; Backhaus, Jan O.
In: Journal of Marine Systems, Vol. 147, 31.07.2015, p. 138-152.Research output: Contribution to journal › Article
TY - JOUR
T1 - The influence of winter convection on primary production
T2 - Journal of Marine Systems
AU - Große, Fabian
AU - Lindemann, Christian
AU - Pätsch, Johannes
AU - Backhaus, Jan O.
PY - 2015/7/31
Y1 - 2015/7/31
N2 - In the recent past observational and modelling studies have shown that the vertical displacement of water parcels, and therefore, phytoplankton particles in regions of deep-reaching convection plays a key role in late winter/early spring primary production. The underlying mechanism describes how convection cells capture living phytoplankton cells and recurrently expose them to sunlight.This study presents a parameterisation called 'phytoconvection' which focusses on the influence of convection on primary production. This parameterisation was implemented into a three-dimensional physical-biogeochemical model and applied to the Northwestern European Continental Shelf and areas of the adjacent Northeast Atlantic. The simulation was compared to a 'conventional' parameterisation with respect to its influence on phytoplankton concentrations during the annual cycle and its effect on the carbon cycle.The simulation using the new parameterisation showed good agreement with observation data recorded during winter, whereas the reference simulation did not capture the observed phytoplankton concentrations. The new parameterisation had a strong influence on the carbon export through the sinking of particulate organic carbon. The carbon export during late winter/early spring significantly exceeded the export of the reference run.Furthermore, a non-hydrostatic convection model was used to evaluate the major assumption of the presented parameterisation which implies the matching of the mixed layer depth with the convective mixing depth. The applied mixed layer depth criterion principally overestimates the actual convective mixing depth. However, the results showed that this assumption is reasonable during late winter, while indicating a mismatch during spring.
AB - In the recent past observational and modelling studies have shown that the vertical displacement of water parcels, and therefore, phytoplankton particles in regions of deep-reaching convection plays a key role in late winter/early spring primary production. The underlying mechanism describes how convection cells capture living phytoplankton cells and recurrently expose them to sunlight.This study presents a parameterisation called 'phytoconvection' which focusses on the influence of convection on primary production. This parameterisation was implemented into a three-dimensional physical-biogeochemical model and applied to the Northwestern European Continental Shelf and areas of the adjacent Northeast Atlantic. The simulation was compared to a 'conventional' parameterisation with respect to its influence on phytoplankton concentrations during the annual cycle and its effect on the carbon cycle.The simulation using the new parameterisation showed good agreement with observation data recorded during winter, whereas the reference simulation did not capture the observed phytoplankton concentrations. The new parameterisation had a strong influence on the carbon export through the sinking of particulate organic carbon. The carbon export during late winter/early spring significantly exceeded the export of the reference run.Furthermore, a non-hydrostatic convection model was used to evaluate the major assumption of the presented parameterisation which implies the matching of the mixed layer depth with the convective mixing depth. The applied mixed layer depth criterion principally overestimates the actual convective mixing depth. However, the results showed that this assumption is reasonable during late winter, while indicating a mismatch during spring.
KW - biogeochemical modelling
KW - convection
KW - Northeast Atlantic
KW - Northwestern European Continental Shelf
KW - parameterisation
KW - primary production
UR - http://www.scopus.com/inward/record.url?scp=84930179979&partnerID=8YFLogxK
U2 - 10.1016/j.jmarsys.2014.07.002
DO - 10.1016/j.jmarsys.2014.07.002
M3 - Article
VL - 147
SP - 138
EP - 152
JO - Journal of Marine Systems
JF - Journal of Marine Systems
SN - 0924-7963
ER -