scholarly journals Effects of storms on primary productivity and air-sea CO<sub>2</sub> exchange in the subarctic western North Pacific: a modeling study

2008 ◽  
Vol 5 (1) ◽  
pp. 65-81 ◽  
Author(s):  
M. Fujii ◽  
Y. Yamanaka
Keyword(s):  
Primary Production ◽  
North Pacific ◽  
Western North Pacific ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Light Limitation ◽  
Co2 Uptake ◽  
Co2 Efflux ◽  
Marine Ecosystem Model ◽  
Strong Winds

Abstract. Biogeochemical responses of the open ocean to storms and their feedback to climate are still poorly understood. Using a marine ecosystem model, we examine biogeochemical responses to the storms in the subarctic western North Pacific. The storms in summer through early autumn enhance primary production by wind-induced nutrient injections into the surface waters while the storms in the other seasons reduce primary production by intensifying light limitation on the phytoplankton growth due to vertical dilution of the phytoplankton. The two compensating effects diminish the storm-induced annual change of primary production to only 1%. On the contrary, the storms enhance the annual sea-to-air CO2 efflux by no less than 34%, resulting from storm-induced strong winds. Our results suggest that previous studies using climatological wind and CO2 data probably underestimated the sea-to-air CO2 efflux during storms in the subarctic western North Pacific, and therefore, that continuous observations are required to reduce uncertainties in the global oceanic CO2 uptake.

scholarly journals Effects of storms on primary productivity and air-sea CO<sub>2</sub> exchange in the subarctic western North Pacific: a modeling study

2008 ◽  
Vol 5 (4) ◽  
pp. 1189-1197 ◽  
Author(s):  
M. Fujii ◽  
Y. Yamanaka
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Light Limitation ◽  
Co2 Uptake ◽  
Net Community Production ◽  
Marine Ecosystem Model ◽  
Strong Winds ◽  
Community Production

Abstract. Biogeochemical responses of the open ocean to storms and their feedback to climate are still poorly understood. Using a marine ecosystem model, we examined biogeochemical responses to the storms in the subarctic western North Pacific. The storms in summer through early autumn enhance net community production by wind-induced nutrient injections into the surface waters while the storms in the other seasons reduce net community production by intensifying light limitation on the phytoplankton growth due to vertical dilution of the phytoplankton. The two compensating effects diminish the storm-induced annual change of net community production to only 1%. On the contrary, the storms reduce the annual oceanic uptake of the atmospheric CO2 by 3%, resulting from storm-induced strong winds. Our results suggest that previous studies using climatological wind, sea level pressure, and CO2 data probably overestimated the air-to-sea CO2 influx during storms in the subarctic western North Pacific, and therefore, continuous high-frequent observations of these variables are required to reduce uncertainties in the global oceanic CO2 uptake.

scholarly journals Biological data assimilation for parameter estimation of a phytoplankton functional type model for the western North Pacific

2017 ◽  
Author(s):  
Yasuhiro Hoshiba ◽  
Takafumi Hirata ◽  
Masahito Shigemitsu ◽  
Hideyuki Nakano ◽  
Taketo Hashioka ◽  
...  
Keyword(s):  
Data Assimilation ◽  
North Pacific ◽  
Western North Pacific ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Biological Data ◽  
Physiological Parameters ◽  
Biological Parameters ◽  
Ecosystem Models ◽  
Marine Ecosystem Model

Abstract. Ecosystem models are used to understand ecosystem dynamics and ocean biogeochemical cycles and require optimum physiological parameters to best represent biological behaviours. These physiological parameters are often tuned up empirically, while ecosystem models have evolved to increase the number of physiological parameters. We developed a three-dimensional (3D) lower trophic level marine ecosystem model known as the Nitrogen, Silicon and Iron regulated Marine Ecosystem Model (NSI-MEM) and employed biological data assimilation using a micro-genetic algorithm to estimate 23 physiological parameters for two phytoplankton functional types in the western North Pacific. The approach used a one-dimensional emulator that referenced satellite data. The 3D NSI-MEM with biological parameters optimised by assimilation improved the timing of a modelled plankton bloom in the subarctic and subtropical regions compared to models without data assimilation. Furthermore, the model was able to simulate not only surface concentrations of phytoplankton but also subsurface maximum concentrations of phytoplankton. Our results show that surface data assimilation of biological parameters from two observatory stations benefits the representation of vertical plankton distribution in the western North Pacific.

scholarly journals Biological data assimilation for parameter estimation of a phytoplankton functional type model for the western North Pacific

Ocean Science ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 371-386 ◽  
Author(s):  
Yasuhiro Hoshiba ◽  
Takafumi Hirata ◽  
Masahito Shigemitsu ◽  
Hideyuki Nakano ◽  
Taketo Hashioka ◽  
...  
Keyword(s):  
Data Assimilation ◽  
North Pacific ◽  
Western North Pacific ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Biological Data ◽  
Physiological Parameters ◽  
Ecosystem Dynamics ◽  
Ecosystem Models ◽  
Marine Ecosystem Model

Abstract. Ecosystem models are used to understand ecosystem dynamics and ocean biogeochemical cycles and require optimum physiological parameters to best represent biological behaviours. These physiological parameters are often tuned up empirically, while ecosystem models have evolved to increase the number of physiological parameters. We developed a three-dimensional (3-D) lower-trophic-level marine ecosystem model known as the Nitrogen, Silicon and Iron regulated Marine Ecosystem Model (NSI-MEM) and employed biological data assimilation using a micro-genetic algorithm to estimate 23 physiological parameters for two phytoplankton functional types in the western North Pacific. The estimation of the parameters was based on a one-dimensional simulation that referenced satellite data for constraining the physiological parameters. The 3-D NSI-MEM optimized by the data assimilation improved the timing of a modelled plankton bloom in the subarctic and subtropical regions compared to the model without data assimilation. Furthermore, the model was able to improve not only surface concentrations of phytoplankton but also their subsurface maximum concentrations. Our results showed that surface data assimilation of physiological parameters from two contrasting observatory stations benefits the representation of vertical plankton distribution in the western North Pacific.

scholarly journals A new marine ecosystem model for the University of Victoria Earth System Climate Model

2012 ◽  
Vol 5 (5) ◽  
pp. 1195-1220 ◽  
Author(s):  
D. P. Keller ◽  
A. Oschlies ◽  
M. Eby
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Light Limitation ◽  
Earth System ◽  
New Model ◽  
Previous Version ◽  
Marine Ecosystem Model ◽  
The University

Abstract. Earth System Climate Models (ESCMs) are valuable tools that can be used to gain a better understanding of the climate system, global biogeochemical cycles and how anthropogenically-driven changes may affect them. Here we describe improvements made to the marine biogeochemical ecosystem component of the University of Victoria's ESCM (version 2.9). Major changes include corrections to the code and equations describing phytoplankton light limitation and zooplankton grazing, the implementation of a more realistic zooplankton growth and grazing model, and the implementation of an iron limitation scheme to constrain phytoplankton growth. The new model is evaluated after a 10 000-yr spin-up and compared to both the previous version and observations. For the majority of biogeochemical tracers and ecosystem processes the new model shows significant improvements when compared to the previous version and evaluated against observations. Many of the improvements are due to better simulation of seasonal changes in higher latitude ecosystems and the effect that this has on ocean biogeochemistry. This improved model is intended to provide a basic new ESCM model component, which can be used as is or expanded upon (i.e., the addition of new tracers), for climate change and biogeochemical cycling research.

Fundy Tidal Power Development and Potential Fish Production in the Gulf of Maine

1986 ◽  
Vol 43 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Daniel E. Campbell ◽  
J. S. Wroblewski
Keyword(s):  
Primary Production ◽  
Gulf Of Maine ◽  
Marine Ecosystem ◽  
Vertical Mixing ◽  
Ecosystem Model ◽  
Fish Production ◽  
Power Development ◽  
Tidal Power ◽  
Marine Ecosystem Model ◽  
Induced Changes

The possible effects of tidal amplitudes altered by Fundy tidal power development upon potential fish production in the Gulf of Maine are examined with a marine ecosystem model. Three areas off the Maine coast are delineated on the basis of winds, tides, and the extent of vertical mixing. An optimum kinetic energy from wind and tide exists for maximum primary production in the water column. Primary production in the model is the base for a simple pelagic food chain leading from phytoplankton through zooplankton to fish. If the construction of a tidal power dam in the upper Bay of Fundy results in a 5–10% increase in tidal amplitude, our first-order model predicts that enhanced vertical mixing from May to October will increase potential fish production along the Maine west coast by 7–12%. Fish production along the Maine east coast and in offshore waters is predicted to remain at present levels. Climatic variation is predicted to have as large an impact on fish production as man-induced changes in vertical mixing caused by tidal power development.

scholarly journals A new marine ecosystem model for the University of Victoria Earth system climate model

2012 ◽  
Vol 5 (2) ◽  
pp. 1135-1201 ◽  
Author(s):  
D. P. Keller ◽  
A. Oschlies ◽  
M. Eby
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Light Limitation ◽  
Earth System ◽  
New Model ◽  
Previous Version ◽  
Marine Ecosystem Model ◽  
The University

Abstract. Earth system climate models (ESCMs) are valuable tools that can be used to gain a better understanding of the climate system, global biogeochemical cycles, and how anthropogenically-driven changes may affect them. Here we describe improvements made to the marine biogeochemical ecosystem component of the University of Victoria's ESCM (version 2.9). Major changes include corrections to the code and equations describing phytoplankton light limitation and zooplankton grazing, the implementation of a more realistic zooplankton growth and grazing model, and the implementation of an iron limitation scheme to constrain phytoplankton growth. The new model is evaluated after a 10 000-yr spin-up and compared to both the previous version and observations. For the majority of biogeochemical tracers and ecosystem processes the new model shows significant improvements when compared to the previous version and evaluated against observations. Many of the improvements are due to better simulation of seasonal changes in higher latitude ecosystems and the effect that this has on ocean biogeochemistry. This improved model is intended to provide a basic new ESCM model component, which can be used as is or expanded upon (i.e., the addition of new tracers), for climate change and biogeochemical cycling research.

Sign in / Sign up

Export Citation Format

Share Document