Modeling Biogeochemical-Physical Interactions and Carbon Flux in the Sargasso Sea (Bermuda Atlantic Time-Series Study Site)

Modeling Biogeochemical-Physical Interactions and Carbon Flux in the Sargasso Sea (Bermuda Atlantic Time-Series Study Site)
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 42
Release: 2018-06-03
Genre:
ISBN: 9781720627777

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

Modeling Biogeochemical-Physical Interactions and Carbon Flux in the Sargasso Sea

Modeling Biogeochemical-Physical Interactions and Carbon Flux in the Sargasso Sea
Author: Sergio R. Signorini
Publisher: BiblioGov
Total Pages: 46
Release: 2013-08
Genre:
ISBN: 9781289275976

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).

Ocean Biogeochemistry

Ocean Biogeochemistry
Author: Michael J.R. Fasham
Publisher: Springer Science & Business Media
Total Pages: 324
Release: 2012-12-06
Genre: Science
ISBN: 3642558445

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.

Seasonal Carbon Cycling in the Sargasso Sea Near Bermuda

Seasonal Carbon Cycling in the Sargasso Sea Near Bermuda
Author: Nicolas Gruber
Publisher: Univ of California Press
Total Pages: 106
Release: 1999-10-04
Genre: Science
ISBN: 0520915968

Each year, the concentration of dissolved inorganic carbon (DIC) in the mixed layer at Station S in the Sargasso Sea decreases from winter to summer by about 30 umol/kg. The authors of this study demonstrate that by simultaneously observing changes in the stable isotopic ration of DIC, it is possible to quantify the contribution of physical and biological processes to this summer-fall drawdown. They find that biology is the dominant contrbutor to the drawdown, but that physical processes also play an important role.

Towards a Model of Ocean Biogeochemical Processes

Towards a Model of Ocean Biogeochemical Processes
Author: Geoffrey T. Evans
Publisher: Springer Science & Business Media
Total Pages: 351
Release: 2013-06-29
Genre: Science
ISBN: 3642846025

Key biogeochemical events in the ocean take place in less than a second, are studied in experiments lasting a few hours, and determine cycles that last over seasons or even years. Models of the controlling processes thus have to take into account these time scales. This book aims at achieving consensus among these controlling processes at all relevant time scales. It helps understand the global carbon cycle including the production and breakdown of solved organic matter and the production, sinking and breakdown of particles. The emphasis on considering all time scales in submodel formulation is new and of interest to all those working in global ocean models and related fields.

Ocean Biogeochemical Dynamics

Ocean Biogeochemical Dynamics
Author: Jorge L. Sarmiento
Publisher: Princeton University Press
Total Pages: 527
Release: 2013-07-17
Genre: Science
ISBN: 1400849071

Ocean Biogeochemical Dynamics provides a broad theoretical framework upon which graduate students and upper-level undergraduates can formulate an understanding of the processes that control the mean concentration and distribution of biologically utilized elements and compounds in the ocean. Though it is written as a textbook, it will also be of interest to more advanced scientists as a wide-ranging synthesis of our present understanding of ocean biogeochemical processes. The first two chapters of the book provide an introductory overview of biogeochemical and physical oceanography. The next four chapters concentrate on processes at the air-sea interface, the production of organic matter in the upper ocean, the remineralization of organic matter in the water column, and the processing of organic matter in the sediments. The focus of these chapters is on analyzing the cycles of organic carbon, oxygen, and nutrients. The next three chapters round out the authors' coverage of ocean biogeochemical cycles with discussions of silica, dissolved inorganic carbon and alkalinity, and CaCO3. The final chapter discusses applications of ocean biogeochemistry to our understanding of the role of the ocean carbon cycle in interannual to decadal variability, paleoclimatology, and the anthropogenic carbon budget. The problem sets included at the end of each chapter encourage students to ask critical questions in this exciting new field. While much of the approach is mathematical, the math is at a level that should be accessible to students with a year or two of college level mathematics and/or physics.

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

One-Dimensional Coupled Ecosystem-Carbon Flux Model for the Simulation of Biogeochemical Parameters at Ocean Weather Station P
Author: S. Signorini
Publisher:
Total Pages: 50
Release: 2000
Genre: Biogeochemistry
ISBN:

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.