One-Dimensional Coupled Ecosystem-Carbon Flux Model for the Simulation of Biogeochemical Parameters at Ocean Weather Station P PDF Download

Author: S. Signorini
Publisher:
ISBN:
Category : Biogeochemistry
Languages : en
Pages : 50

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Book Description
In this report, we describe the model functionality and analyze its application to the seasonal and interannual variations of phytoplankton, nutrients, pCO2 and CO2 concentrations in the Eastern Subarctic Pacific at Ocean Weather Station P. We use a verified one-dimensional ecosystem model, coupled with newly incorporated carbon flux and carbon chemistry components, to simulate 22 years. This relatively long period of simulation verifies and extends the findings of previous studies using an explicit approach for the biological component and realistic coupling with the carbon flux dynamics. The slow currents and the horizontally homogeneous ocean in the Subarctic Pacific make OWS P one of the best available candidates for modeling the chemistry of the upper ocean in one dimension. The chlorophyll and ocean currents composite for 1998 shown in Figure 1 illustrates this permise. The chlorophyll concentration map was derived from SeaWiFS data and the currents are from an OGCM simulation.

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720653035
Category :
Languages : en
Pages : 48

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Book Description
In this Technical Publication, we describe the model functionality and analyze its application to the seasonal and interannual variations of phytoplankton, nutrients, pCO2 and CO2 concentrations in the eastern subarctic Pacific at Ocean Weather Station P (OWSP, 50 deg. N 145 deg. W). We use a verified one-dimensional ecosystem model, coupled with newly incorporated carbon flux and carbon chemistry components, to simulate 22 years (1958-1980) of pCO2 and CO2 variability at Ocean Weather Station P (OWS P). This relatively long period of simulation verifies and extends the findings of previous studies using an explicit approach for the biological component and realistic coupling with the carbon flux dynamics. The slow currents and the horizontally homogeneous ocean in the subarctic Pacific make OWS P one of the best available candidates for modeling the chemistry of the upper ocean in one dimension. The chlorophyll and ocean currents composite for 1998 illustrates this premise. The chlorophyll concentration map was derived from SeaWiFS data and the currents are from an OGCM simulation (from R. Murtugudde).Signorini, S. and McClain, C. and Christian, J. and Wong, C. S.Goddard Space Flight CenterPHYTOPLANKTON; ANNUAL VARIATIONS; BIOGEOCHEMISTRY; MATHEMATICAL MODELS; MARINE CHEMISTRY; ENVIRONMENT MODELS; CARBON DIOXIDE CONCENTRATION; WEATHER STATIONS; VARIABILITY; SIMULATION; SEA SURFACE TEMPERATURE; REMOTE SENSING; PACIFIC OCEAN; OCEAN CURRENTS; MARINE METEOROLOGY; ECOSYSTEMS

Author: Michael J.R. Fasham
Publisher: Springer Science & Business Media
ISBN: 3642558445
Category : Science
Languages : en
Pages : 324

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Book Description
Oceans account for 50% of the anthropogenic CO2 released into the atmosphere. During the past 15 years an international programme, the Joint Global Ocean Flux Study (JGOFS), has been studying the ocean carbon cycle to quantify and model the biological and physical processes whereby CO2 is pumped from the ocean's surface to the depths of the ocean, where it can remain for hundreds of years. This project is one of the largest multi-disciplinary studies of the oceans ever carried out and this book synthesises the results. It covers all aspects of the topic ranging from air-sea exchange with CO2, the role of physical mixing, the uptake of CO2 by marine algae, the fluxes of carbon and nitrogen through the marine food chain to the subsequent export of carbon to the depths of the ocean. Special emphasis is laid on predicting future climatic change.

Author: Nasa Technical Reports Server (Ntrs)
Publisher: BiblioGov
ISBN: 9781289271459
Category :
Languages : en
Pages : 60

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Book Description
This TM consists of two chapters. Chapter I describes the development of a coupled, one-dimensional biogeochemical model using turbulence closure mixed layer (TCMLM) dynamics. The model is applied to the Sargasso Sea at the BATS (Bermuda Atlantic Time Series) site and the results are compared with a previous model study in the same region described in NASNTP-2001-209991. The use of the TCMLM contributed to some improvements in the model simulation of chlorophyll, PAR, nitrate, phosphate, and oxygen, but most importantly, the current model achieved good agreement with the data with much more realistic background eddy diffusivity. However, off-line calculations of horizontal transport of biogeochemical properties revealed that one-dimensional dynamics can only provide a limited assessment of the nutrient and carbon balances at BATS. Future studies in the BATS region will require comprehensive three-dimensional field studies, combined with three-dimensional eddy resolving numerical experiments, to adequately quantify the impact of the local and remote forcing on ecosystem dynamics and carbon cycling. Chapter II addresses the sensitivity of global sea-air CO, flux estimates to wind speed, temperature, and salinity. Sensitivity analyses of sea-air CO, flux to wind speed climatologies, gas transfer algorithms, SSS and SST were conducted for the global oceans and regional domains. Large uncertainties in the global sea-air flux are identified, primarily due to the different gas transfer algorithms used. The sensitivity of the sea-air flux to SST and SSS is similar in magnitude to the effect of using different wind climatologies. Globally, the mean ocean uptake of CO, changes by 5 to 16%, depending upon the combination of SST and SSS used.

Author: Nabir Mamnun
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Predicting climate change necessitates a thorough understanding of marine biogeochemical (BGC) processes and the coupling between marine ecosystems and the global carbon cycle. Ocean BGC models are tools employed for this purpose. However, current ocean models used to simulate and thus better understand the ocean BGC processes are highly uncertain in their parameterization. This work delves into research to quantify uncertainties that arise in ocean BGC models and obtain improved parameters to reduce those uncertainties utilizing the BGC ocean model Regulated Ecosystem Model Version 2. A Global Sensitivity Analysis (GSA) is performed to identify which parameters most influence the uncertainty of model outputs in a one-dimensional (1-D) configuration at two ocean sites in the North Atlantic (BATS) and the Mediterranean Sea (DYFAMED). This work finds that the grazing parameter, the maximum chlorophyll-to-nitrogen ratio, the photosynthesis parameters, and the chlorophyll degradation rate are significant for BGC simulation. This dissertation uses ensemble data assimilation to estimate the most important BGC process parameters. First, data assimilation experiments are carried out in a 1-D model using an ensemble Kalman Filter to estimate preselected BGC parameters at BATS and DYFAMED stations. Subsequently, the scope and application of experiments are broadened to a global scale 3-D model by incorporating spatial variations in parameter values. Replacing the default parameter values with the optimal values obtained in this work improves the model outcomes in both 1-D and 3-D configurations. This work underscores the importance of spatially varying parameter optimization and highlights the potential benefits of incorporating spatially varying BGC parameters in regional and global 3-D BGC models. Through such rigorous scientific endeavors, we inch closer to a more coherent understanding of the complex interplay between the ocean BGC processes and the carbon cycle.

Author: Yiqi Luo
Publisher: CRC Press
ISBN: 0429531303
Category : Nature
Languages : en
Pages : 602

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Book Description
Carbon moves through the atmosphere, through the oceans, onto land, and into ecosystems. This cycling has a large effect on climate – changing geographic patterns of rainfall and the frequency of extreme weather – and is altered as the use of fossil fuels adds carbon to the cycle. The dynamics of this global carbon cycling are largely predicted over broad spatial scales and long periods of time by Earth system models. This book addresses the crucial question of how to assess, evaluate, and estimate the potential impact of the additional carbon to the land carbon cycle. The contributors describe a set of new approaches to land carbon cycle modeling for better exploring ecological questions regarding changes in carbon cycling; employing data assimilation techniques for model improvement; and doing real- or near-time ecological forecasting for decision support. This book strives to balance theoretical considerations, technical details, and applications of ecosystem modeling for research, assessment, and crucial decision making. Key Features Helps readers understand, implement, and criticize land carbon cycle models Offers a new theoretical framework to understand transient dynamics of land carbon cycle Describes a suite of modeling skills – matrix approach to represent land carbon, nitrogen, and phosphorus cycles; data assimilation and machine learning to improve parameterization; and workflow systems to facilitate ecological forecasting Introduces a new set of techniques, such as semi-analytic spin-up (SASU), unified diagnostic system with a 1-3-5 scheme, traceability analysis, and benchmark analysis, for model evaluation and improvement Related Titles Isabel Ferrera, ed. Climate Change and the Oceanic Carbon Cycle: Variables and Consequences (ISBN 978-1-774-63669-5) Lal, R. et al., eds. Soil Processes and the Carbon Cycle (ISBN 978-0-8493-7441-8) Windham-Myers, L., et al., eds. A Blue Carbon Primer: The State of Coastal Wetland Carbon Science, Practice and Policy (ISBN 978-0-367-89352-1)

Author: Sergio R. Signorini
Publisher: BiblioGov
ISBN: 9781289275976
Category :
Languages : en
Pages : 46

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Book Description
An ecosystem-carbon cycle model is used to analyze the biogeochemical-physical interactions and carbon fluxes in the Bermuda Atlantic Time-series Study (BATS) site for the period of 1992-1998. The model results compare well with observations (most variables are within 8% of observed values). The sea-air flux ranges from -0.32 to -0.50 mol C/sq m/yr, depending upon the gas transfer algorithm used. This estimate is within the range (-0.22 to -0.83 mol C/sq m/yr) of previously reported values which indicates that the BATS region is a weak sink of atmospheric CO2. The overall carbon balance consists of atmospheric CO2 uptake of 0.3 Mol C/sq m/yr, upward dissolved inorganic carbon (DIC) bottom flux of 1.1 Mol C/sq m/yr, and carbon export of 1.4 mol C/sq m/yr via sedimentation. Upper ocean DIC levels increased between 1992 and 1996 at a rate of approximately 1.2 (micro)mol/kg/yr, consistent with observations. However, this trend was reversed during 1997-1998 to -2.7 (micro)mol/kg/yr in response to hydrographic changes imposed by the El Nino-La Nina transition, which were manifested in the Sargasso Sea by the warmest SST and lowest surface salinity of the period (1992-1998).

Author: Christoph Heinze
Publisher: Elsevier Inc. Chapters
ISBN: 0128058757
Category : Science
Languages : en
Pages : 69

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Book Description
Biogeochemical ocean general circulation models are important tools for quantifying the marine carbon cycle and its feedback to the climate system. These models simulate the inorganic carbon cycle and also the organic carbon cycle through a series of simplified process parameterizations. This chapter presents an overview of the major concepts and methods in marine biogeochemical modeling including the combination of models with observations. Because of the climatic relevance of the carbon cycle, major emphasis is placed on it, but some other related matter cycles are also touched upon. New developments in ocean biogeochemistry during the last decade are described including the marine anthropogenic carbon uptake and ocean acidification. The chapter tries to acquaint scientists from other disciplines with marine biogeochemical modeling and provides key literature resources for further in-depth studies.

Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781723860836
Category : Science
Languages : en
Pages : 44

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Book Description
An ecosystem-carbon cycle model is used to analyze the biogeochemical-physical interactions and carbon fluxes in the Bermuda Atlantic Time-series Study (BATS) site for the period of 1992-1998. The model results compare well with observations (most variables are within 8% of observed values). The sea-air flux ranges from -0.32 to -0.50 mol C/sq m/yr, depending upon the gas transfer algorithm used. This estimate is within the range (-0.22 to -0.83 mol C/sq m/yr) of previously reported values which indicates that the BATS region is a weak sink of atmospheric CO2. The overall carbon balance consists of atmospheric CO2 uptake of 0.3 Mol C/sq m/yr, upward dissolved inorganic carbon (DIC) bottom flux of 1.1 Mol C/sq m/yr, and carbon export of 1.4 mol C/sq m/yr via sedimentation. Upper ocean DIC levels increased between 1992 and 1996 at a rate of approximately 1.2 (micro)mol/kg/yr, consistent with observations. However, this trend was reversed during 1997-1998 to -2.7 (micro)mol/kg/yr in response to hydrographic changes imposed by the El Nino-La Nina transition, which were manifested in the Sargasso Sea by the warmest SST and lowest surface salinity of the period (1992-1998).Signorini, Sergio R. and McClain, Charles R. and Christian, James R.Goddard Space Flight CenterATMOSPHERIC COMPOSITION; BIOGEOCHEMISTRY; CARBON CYCLE; ENVIRONMENT MODELS; ANNUAL VARIATIONS; ALGORITHMS; CARBON DIOXIDE CONCENTRATION; HYDROGRAPHY; SARGASSO SEA; AIR WATER INTERACTIONS; EL NINO; VERTICAL DISTRIBUTION

Author: Carlos Roberto Mechoso
Publisher: World Scientific
ISBN: 9811232954
Category : Science
Languages : en
Pages : 203

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Book Description
Coupled atmosphere-ocean models are at the core of numerical climate models. There is an extraordinarily broad class of coupled atmosphere-ocean models ranging from sets of equations that can be solved analytically to highly detailed representations of Nature requiring the most advanced computers for execution. The models are applied to subjects including the conceptual understanding of Earth's climate, predictions that support human activities in a variable climate, and projections aimed to prepare society for climate change. The present book fills a void in the current literature by presenting a basic and yet rigorous treatment of how the models of the atmosphere and the ocean are put together into a coupled system. The text of the book is divided into chapters organized according to complexity of the components that are coupled. Two full chapters are dedicated to current efforts on the development of generalist couplers and coupling methodologies all over the world.