Verdy (CMS 2011) Project Profile   (updated 08-Jan-2018)
Project Title:Towards a 4D-Var Approach for Estimation of Air-Sea Carbon Dioxide Fluxes

Science Team
Members:

Ariane Verdy, Scripps Institution of Oceanography (Project Lead)
Robert (Bob) Key, Princeton University

Project Duration: 2012 - 2014
Solicitation:NASA: Carbon Monitoring System (2011)
Abstract: The challenge- Any Carbon Monitoring System (CMS) must account for fluxes of carbon between the atmosphere and the oceans, the world s largest reservoir of carbon dioxide (CO2). Currently, air-sea CO2 flux estimates are produced by sophisticated physical-biogeochemical models. However, these models still fail to represent significant patterns in the observed fluxes, and these discrepancies are thought to be largely due to errors in the simulation of biogeochemical processes. Our goal- This proposal capitalizes on two recent developments in oceanography to lay the groundwork for a global ocean CMS with improved biogeochemistry. Satellite measurements of the surface ocean and sensor-based measurements of the interior ocean are rapidly increasing the temporal and spatial coverage of biogeochemical data. Simultaneously, the development of four-dimensional variational assimilation (4D-Var) modeling has combined the forward modeling and traditional static inversion approaches to overcome the primary limitations of both: forward models estimate what could have happened in the ocean rather than what actually happened, and inversions cannot yield predictions. The 4D-Var approach automates the process of adjusting initial conditions and model parameters to produce an optimal fit of the model to physical constraints and all available observations. Our vision is of a state-of-the-art global physical-biogeochemical ocean model that incorporates data from the growing global network of satellites, sensors, and shipboard measurements to improve its estimates of air-sea CO2 fluxes. Our contribution- We will provide the missing components for 4D-Var physical-biogeochemical assimilation. As we build toward our goal of a global model-observation synthesis, each step of the proposed research will generate independently valuable scientific products: 1. We will test the efficacy of extending the 4D-Var approach to biogeochemistry by using it to optimize both the idealized biogeochemical and physical state of an eddy-resolving model of the California Current Ecosystem (CCE) for 2007-2011. The model will be optimized by adjusting the initial conditions, boundary conditions, external forcing, and parameter values to reduce the misfit between the model and the dense and diverse observations (including in situ measurements of carbon, oxygen, phosphate, pH, and alkalinity) available of the CCE during this time period. 2. We will further develop the biogeochemical component of the model to allow assimilation of satellite-based chlorophyll estimates and to improve the representation of other constraints, and optimize this new implementation of the physical-biogeochemical model to improve our estimate of air-sea CO2 fluxes in the CCE. 3. We will extend the data-processing of hydrographic observations to produce a self-consistent dataset of the quality, richness of properties, and temporal extent that will be required to constrain a global 4D-Var biogeochemical model. GLODAPv2 (GLobal Ocean Data Analysis Project version 2) will be a calibrated unification of existing biogeochemical data products and new data over the period 1972-2011. As more observations become available, state estimation is undoubtedly the way forward for addressing the objectives of NASA's CMS by bringing together observations and modeling tools to generate accurate high-resolution and time-varying maps of air-sea CO2 fluxes. Together, the development of 4D-Var methods and the observational dataset will enable global model-observation syntheses of the ocean carbon cycle over climate-relevant time scales.
Project Associations:
  • CMS
CMS Primary Theme:
  • Ocean-Atmosphere Flux
CMS Science Theme(s):
  • Ocean-Atmosphere Flux

Participants:

Brendan Carter, NOAA
Robert (Bob) Key, Princeton University
Matthew Mazloff, Scripps Institution of Oceanography
Jorge Sarmiento, Princeton University
Ariane Verdy, Scripps Institution of Oceanography

Contact Support to request an email list of project participants.

Project URL(s): http://iod.ucsd.edu/~averdy/becco.html
http://cdiac.ornl.gov/oceans/glodap/
 
Data
Products:
Product Title:  Global Ocean Data Analysis Project version 2 (GLODAPv2), a comprehensive data product of ocean carbon and biogeochemistry observations.
Time Period:  1973-2013
Description:  - Compile a calibrated dataset of in-situ ocean observations needed to constrain a global 4D-Var biogeochemical model.
Status:  Archived
CMS Science Theme(s):  Ocean-Atmosphere Flux
Keywords:  Flux/Movement (; oceanic; ; atmospheric)
Spatial Extent:  Global
Spatial Resolution:  1°
Temporal Frequency:  (climatology)
Input Data Products:  Available high quality shipboard data from 1973-present provided by the global research community
Algorithm/Models Used:  
Evaluation:  All parameters are subject to 2 rounds of quality control including basin scale inversion as well as crossover type data comparisons.
Intercomparison Efforts/Gaps:  GLODAPv1, CARINA, PACIFICA
Uncertainty Estimates:  Measurement accuracy is generally determined by simultaneous analysis of primary or secondary standards of known concentration.
Uncertainty Categories:  data-data comparison
Application Areas:  - Global carbon budget calculations; - Watershed protection plans; - Ocean acidification mitigation
Relevant Policies/Programs:  FOARAM, President's Executive Order on Oceans (EO 13547), NOAA Ocean Acidification Program, IOCCP, GO-SHIP, CWA, Doha/Kyoto, USCCSP, IPCC
Potential Users:  NOAA, EPA, White House Council on Environmental Quality, any oceanographer or modeler who needs to know the global ocean 3-D distribution of carbon system parameters and tracers that are not commonly cataloged by National Oceanographic Data Center
Stakeholders:  
Current Application Readiness Level:  7
Start Application Readiness Level:  3
Target Application Readiness Level:  7
Future Developments:  - Coordinate to release the data through the carbon dioxide information analysis Center (CDIAC) website.
Limitations:  - Summer bias in GLODAPv2 shipboard data collection.; - Insufficient or no data in GLODAPv2 for Southern Ocean, Indonesian throughflow region, Gulf of Mexico, Caribbean Sea, and less marginal seas.; - Insufficient data to produce global-scale, seasonal oc
Date When Product Available:  2016-08-16
Assigned Data Center:  NODC
Metadata URL(s):

https://cdiac.ess-dive.lbl.gov/ftp/oceans/GLODAPv2/Data_Products/

https://www.nodc.noaa.gov/ocads/oceans/GLODAPv2/

http://cchdo.ucsd.edu/
Data Server URL(s):

https://cdiac.ess-dive.lbl.gov/ftp/oceans/GLODAPv2/Data_Products/

https://www.nodc.noaa.gov/ocads/oceans/GLODAPv2/

http://cchdo.ucsd.edu/
Archived Data Citation:  Key, R.M., A. Olsen, S. van Heuven, S. K. Lauvset, A. Velo, X. Lin, C. Schirnick, A. Kozyr, T. Tanhua, M. Hoppema, S. Jutterström, R. Steinfeldt, E. Jeansson, M. Ishi, F. F. Perez, and T. Suzuki. 2015. Global Ocean Data Analysis Project, Version 2 (GLODAPv2), ORNL/CDIAC-162, NDP-P093. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee.

DOI: 10.3334/CDIAC/OTG.NDP093_GLODAPv2

Product Title:  Ocean Biogeochemistry in the California Current System 2007-2010 L4 Monthly
Start Date:  01/2007      End Date:  12/2010     (2007-2010)
Description:  A coupled physical-biogeochemical ocean model (the MITgcm with BLING biogeochemistry) is a least squares fit to all available ocean observations in the region of the California Current System. This is accomplished iteratively through the adjoint method, using the methodology developed by the Consortium for Estimating the Circulation and Climate of the Ocean (ECCO). The result is a physically realistic estimate of the ocean state. The model domain extends from 28N to 40N and from 130W to 114W. It has a 1/16-degree horizontal resolution (~7km) and 72 vertical levels.

The NASA Carbon Monitoring System (CMS) is designed to make significant contributions in characterizing, quantifying, understanding, and predicting the evolution of global carbon sources and sinks through improved monitoring of carbon stocks and fluxes. The System will use the full range of NASA satellite observations and modeling/analysis capabilities to establish the accuracy, quantitative uncertainties, and utility of products for supporting national and international policy, regulatory, and management activities. CMS will maintain a global emphasis while providing finer scale regional information, utilizing space-based and surface-based data and will rapidly initiate generation and distribution of products both for user evaluation and to inform near-term policy development and planning.
Status:  Archived
CMS Science Theme(s):  Ocean-Atmosphere Flux
Keywords:  Flux/Movement (oceanic; atmospheric)
Spatial Extent:  California coastal ocean
Spatial Resolution:  7 km
Temporal Frequency:  Monthly and hourly
Input Data Products:  Satellite: Altimeter SSH (Jason1-2, TOPEX), Microwave SST, Ocean Color (MODIS), In Situ temperature, salinity, biogeochemistry
Algorithm/Models Used:  BLING (Biogeochemistry with Light, Iron, Nutrient and Gases) coupled to the MITgcm (ocean general circulation model)
Evaluation:  Adjoint model evaluation of the cost function (misfit between observations and model)
Intercomparison Efforts/Gaps:  ECCO2-Darwin, ECCOv4
Uncertainty Estimates:  We will quantify the consistency of the model with available observations
Uncertainty Categories:  model-data comparison
Application Areas:  - Global carbon budget calculations; - Watershed protection plans; - Ocean acidification mitigation
Relevant Policies/Programs:  FOARAM, President's Executive Order on Oceans (EO 13547), NOAA Ocean Acidification Program, IOCCP, GO-SHIP, CWA, Doha/Kyoto, USCCSP, IPCC
Potential Users:  NOAA, EPA, White House Council on Environmental Quality, any oceanographer or modeler who needs to know the global ocean 3-D distribution of carbon system parameters and tracers that are not commonly cataloged by National Oceanographic Data Center
Stakeholders:  
Current Application Readiness Level:  5
Start Application Readiness Level:  3
Target Application Readiness Level:  5
Future Developments:  Post new data on the Biogeochemistry Estimation in the California Coastal Ocean (BECCO) website.
Limitations:  - Limited ground-based data to validate satellite and model derived measurements. ; - Model-based errors due to simplification of a complex system.
Date When Product Available:  January 2018
Assigned Data Center:  GES DISC
Metadata URL(s):

https://acdisc.gsfc.nasa.gov/data/CMS/CMS_OCE_BGC_CCS.1/doc/README.CMS_OCE_BGC_CCS_V1.pdf

http://sose.ucsd.edu/CASE/case_stateestimation_data.html
Data Server URL(s):

https://acdisc.gsfc.nasa.gov/data/CMS/CMS_OCE_BGC_CCS.1/

http://sose.ucsd.edu/CASE/
Archived Data Citation:  Ariane Verdy(2017), Ocean Biogeochemistry in the California Current System 2007-2010 L4 Monthly, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), DOI: 10.5067/G854SWM56S7H

Bounding Coordinates:
West Longitude:-129.00000 East Longitude:-114.00000
North Latitude:39.95000 South Latitude:27.20000

 
Publications: Verdy, A., Mazloff, M. R., Cornuelle, B. D., Kim, S. Y. 2014. Wind-Driven Sea Level Variability on the California Coast: An Adjoint Sensitivity Analysis. Journal of Physical Oceanography. 44(1), 297-318. DOI: 10.1175/JPO-D-13-018.1

Archived Data Citations: Key, R.M., A. Olsen, S. van Heuven, S. K. Lauvset, A. Velo, X. Lin, C. Schirnick, A. Kozyr, T. Tanhua, M. Hoppema, S. Jutterström, R. Steinfeldt, E. Jeansson, M. Ishi, F. F. Perez, and T. Suzuki. 2015. Global Ocean Data Analysis Project, Version 2 (GLODAPv2), ORNL/CDIAC-162, NDP-P093. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee. DOI: 10.3334/CDIAC/OTG.NDP093_GLODAPv2

Ariane Verdy(2017), Ocean Biogeochemistry in the California Current System 2007-2010 L4 Monthly, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), DOI: 10.5067/G854SWM56S7H