@ARTICLE
Goux, O., Pfeffer, J., Blazquez, A., Weaver, A.T. and Ablain, M. (2023) A mass conserving filter based on diffusion for Gravity Recovery and Climate Experiment (GRACE) spherical harmonics solutions, Geophysical Journal International, 234 (1) , pp. 56-72, doi: 10.1093/gji/ggad016
[bibtex]
@ARTICLE{AR-PA-23-18,
author = {Goux, O. and Pfeffer, J. and Blazquez, A. and Weaver, A.T. and Ablain, M. },
title = {A mass conserving filter based on diffusion for Gravity Recovery and Climate Experiment (GRACE) spherical harmonics solutions},
year = {2023},
number = {1},
volume = {234},
pages = {56-72},
doi = {10.1093/gji/ggad016},
journal = {Geophysical Journal International},
abstract = {Over the past two decades, the GRACE (Gravity Recovery and Climate Experiment) and GRACE Follow-On mission (GRACE-FO) have provided monthly measurements of the gravity field as sets of Stokes coefficients, referred to as spherical harmonics solutions. The variations of the gravity field can be used to infer mass variations on the surface of the Earth, mostly driven by the redistribution of water. However, unconstrained GRACE and GRACE-FO solutions are affected by strong correlated errors, easily identified as stripes along the North-South direction in the spatial domain. Here, we develop a filter based on the principle of diffusion to remove correlated errors and access the underlying geophysical signals. In contrast to many filters developed for this task, diffusion filters allow a spatially variable level of filtering that can be adapted to match spatially variable signal-to-noise ratios. Most importantly, the formalism of diffusion allows the implementation of boundary conditions, which can be used to prevent any flux through the coastlines during the filtering step. As mass conservation is enforced in the filter, global indicators such as trends in the global mean ocean mass are preserved. Compared with traditional filters, diffusion filters ensure the consistency of the solution at global and regional scales for ocean applications. Because leakage errors occurring during the filtering step are suppressed, better agreement is found when comparing diffusion-filtered spherical harmonic solutions with mascon solutions and independent estimates based on altimetry and in situ data.}}
Goux, O., Gürol, S., Weaver, A.T., Diouane, Y. and Guillet, O. (2023) Impact of correlated observation errors on the conditioning of variational data assimilation problems, Numerical Linear Algebra with Applications, 31 (1) , pp. e2529, doi: 10.1002/nla.2529
[bibtex]
@ARTICLE{AR-PA-23-118,
author = {Goux, O. and Gürol, S. and Weaver, A.T. and Diouane, Y. and Guillet, O. },
title = {Impact of correlated observation errors on the conditioning of variational data assimilation problems},
year = {2023},
number = {1},
volume = {31},
pages = {e2529},
doi = {10.1002/nla.2529},
journal = {Numerical Linear Algebra with Applications}}
Lea, D.J., While, J., Martin, M.J., Weaver, A.T., Storto, A. and Chrust, M. (2022) A new global ocean ensemble system at the Met Office: Assessing the impact of hybrid data assimilation and inflation settings, Quarterly Journal of the Royal Meteorological Society, 148 (745) , pp. 1996-2030, doi: 10.1002/qj.4292
[bibtex]
@ARTICLE{AR-PA-22-48,
author = {Lea, D.J. and While, J. and Martin, M.J. and Weaver, A.T. and Storto, A. and Chrust, M. },
title = {A new global ocean ensemble system at the Met Office: Assessing the impact of hybrid data assimilation and inflation settings},
year = {2022},
number = {745},
volume = {148},
pages = { 1996-2030},
doi = {10.1002/qj.4292},
journal = {Quarterly Journal of the Royal Meteorological Society},
abstract = {We have developed a global ocean and sea-ice ensemble forecasting system based on the operational FOAM (Forecasting Ocean Assimilation Model) system run at the Met Office. The ocean model NEMO and the CICE sea-ice model run at 1/4° resolution and the system assimilates data using a three-dimensional variational assimilation (3DVar) version of NEMOVAR. This data assimilation (DA) system can perform hybrid ensemble/variational assimilation. A 36 member ensemble of hybrid-ensemble-variational assimilation systems with perturbed observations (values and locations) has been set-up, with each member forced at the surface by a separate member of the Met Office Global-Regional Ensemble Prediction System (MOGREPS-G). The unperturbed member is forced by atmospheric fields from the Met Office operational Numerical Weather Prediction (NWP) deterministic system. The system includes stochastic model perturbations and a Relaxation to Prior Spread (RTPS) inflation scheme. A control run of the system using an ensemble of 3DVars is shown to be generally reliable for sea level anomaly (SLA), temperature and salinity (the ensemble spread being a good representation of the uncertainty in the ensemble mean), although the ensemble is underspread in eddying regions. The ensemble mean gives a 4% reduction in error in SLA compared with the deterministic 3DVar system currently used operationally. The system was tested with different weights for the ensemble component of the hybrid background error covariance matrix and different inflation factors. The best results, in terms of short-range forecast error and ensemble reliability statistics, were obtained with hybrid three-dimensional ensemble variational DA (3DEnVar). The RTPS inflation scheme is shown to be beneficial in producing an appropriate ensemble spread in response to hybrid DA. 3DEnVar with an ensemble hybrid weight of 0.8 leads to a reduction of 20% (5%) in the ensemble mean error for SLA (profile temperature and salinity) compared with an ensemble of standard 3DVars.
}}
Weaver, A.T., Chrust, M., Ménétrier, B. and Piacentini, A (2021) An evaluation of methods for normalizing diffusion-based covariance operators in variational data assimilation, Quarterly Journal of the Royal Meteorological Society, 147 (734) , pp. 289-320, doi: 10.1002/qj.3918
[bibtex]
@ARTICLE{AR-PA-21-29,
author = {Weaver, A.T. and Chrust, M. and Ménétrier, B. and Piacentini, A },
title = {An evaluation of methods for normalizing diffusion-based covariance operators in variational data assimilation},
year = {2021},
number = {734},
volume = {147},
pages = {289-320},
doi = {10.1002/qj.3918},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Chrust, M., Balmaseda, M.A., Browne, P., Martin, M., Storto, A., Vidard, A., Weaver, A.T. and Zuo, H. (2021) Ensemble of Data Assimilations in the ocean for better exploitation of surface observations, ECMWF Newsletter, 168
[bibtex]
[url]
@ARTICLE{AR-PA-21-249,
author = {Chrust, M. and Balmaseda, M.A. and Browne, P. and Martin, M. and Storto, A. and Vidard, A. and Weaver, A.T. and Zuo, H. },
title = {Ensemble of Data Assimilations in the ocean for better exploitation of surface observations},
year = {2021},
volume = {168},
journal = {ECMWF Newsletter},
url = {https://www.ecmwf.int/en/newsletter/168/news/ensemble-data-assimilations-ocean-better-exploitation-surface-observations}}
Moore, A.M., Martin, M., Akella, S., Arango, H.G., Balmaseda, M., Bertino, L., Ciavatta, S., Cornuelle, B., Cummings, J., Frolov, S., Lermusiaux, P., Oddo, P., Oke, P., Storto, A., Teruzzi, A., Vidard, A. and Weaver, A.T. (2019) Synthesis of Ocean Observations Using Data Assimilation for Operational, Real-Time and Reanalysis Systems: A More Complete Picture of the State of the Ocean, Frontiers in Marine Science, 6, pp. 90, ISSN 2296-7745, doi: 10.3389/fmars.2019.00090
[bibtex] [pdf]
@ARTICLE{AR-PA-19-51,
author = {Moore, A.M. and Martin, M. and Akella, S. and Arango, H.G. and Balmaseda, M. and Bertino, L. and Ciavatta, S. and Cornuelle, B. and Cummings, J. and Frolov, S. and Lermusiaux, P. and Oddo, P. and Oke, P. and Storto, A. and Teruzzi, A. and Vidard, A. and Weaver, A.T. },
title = {Synthesis of Ocean Observations Using Data Assimilation for Operational, Real-Time and Reanalysis Systems: A More Complete Picture of the State of the Ocean},
year = {2019},
volume = {6},
pages = {90},
issn = {2296-7745},
doi = {10.3389/fmars.2019.00090},
journal = {Frontiers in Marine Science},
abstract = {Ocean data assimilation is increasingly recognized as crucial for the accuracy of real-time ocean prediction systems. Here, the current status of ocean data assimilation in support of the operational demands of analysis and forecasting is reviewed, focusing on the methods currently adopted in operational prediction systems. Significant challenges associated with the most commonly employed approaches are identified and discussed. Overarching issues faced by ocean data assimilation in general are also addressed, and important future directions in response to scientific advances, evolving and forthcoming ocean observing systems and the needs of stakeholders and downstream applications are presented},
pdf = {https://www.frontiersin.org/article/10.3389/fmars.2019.00090}}
Guillet, O., Weaver, A.T., Vasseur, X., Michel, Y., Gratton, S. and Gürol, S. (2019) Modelling spatially correlated observation errors in variational data assimilation using a diffusion operator on an unstructured mesh, Quarterly Journal of the Royal Meteorological Society, 145 (722) , pp. 1947-1967, ISSN 0035-9009, doi: 10.1002/qj.3537
[bibtex] [pdf]
@ARTICLE{AR-PA-19-127,
author = {Guillet, O. and Weaver, A.T. and Vasseur, X. and Michel, Y. and Gratton, S. and Gürol, S. },
title = {Modelling spatially correlated observation errors in variational data assimilation using a diffusion operator on an unstructured mesh},
year = {2019},
number = {722},
volume = {145},
pages = {1947-1967},
issn = {0035-9009},
doi = {10.1002/qj.3537},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {correlation functions, diffusion operator, finite element method, observation errors, unstructured mesh, variational assimilation},
pdf = { https://doi.org/10.1002/qj.3537}}
Weaver, A.T., Gürol, S., Tshimanga, J., Chrust, M. and Piacentini, A (2018) "Time"-parallel diffusion-based correlation operators, Quarterly Journal of the Royal Meteorological Society
[bibtex]
@ARTICLE{AR-PA-18-63,
author = {Weaver, A.T. and Gürol, S. and Tshimanga, J. and Chrust, M. and Piacentini, A },
title = {“Time”-parallel diffusion-based correlation operators},
year = {2018},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Weaver, A.T., Gürol, S., Tshimanga, J., Chrust, M. and Piacentini, A (2018) “Time”‐parallel diffusion‐based correlation operators, Quarterly Journal of the Royal Meteorological Society, 144, pp. 2067--2088, doi: 10.1002/qj.3302
[bibtex] [pdf]
@ARTICLE{AR-PA-18-168,
author = {Weaver, A.T. and Gürol, S. and Tshimanga, J. and Chrust, M. and Piacentini, A },
title = {“Time”‐parallel diffusion‐based correlation operators},
year = {2018},
volume = {144},
pages = {2067--2088},
doi = {10.1002/qj.3302},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://doi.org/10.1002/qj.3302}}
Buizza, R., Brönnimann, S., Haimberger, L., Laloyaux, P., Martin, M.J., Fuentes , M., Alonso-Balmaseda, M., Becker, A., Blaschek, M., Dahlgren, P., de Boisseson, E., Dee, D., Doutriaux-Boucher, M., Feng, X., John, V.O., Haines, K., Jourdain, S., Kosaka, Y., Lea, D., Lemarié, F., Mayer, M., Messina, P., Perruche, C., Peylin, P., Pullainen, J., Rayner, N., Rustemeier, E., Schepers, D., Saunders, R., Schulz, J., Sterin, A., Stichelberger, S., Storto, A., Testut, C.-E., Valente, M.-A., Vidard, A., Vuichard, N., Weaver, A.T., While, J. and Ziese, M. (2018) The EU-FP7 ERA-CLIM2 Project Contribution to Advancing Science and Production of Earth System Climate Reanalyses, Bulletin of the American Meteorological Society, 99, pp. 1003--1014, doi: 10.1175/BAMS-D-17-0199.1
[bibtex] [pdf]
@ARTICLE{AR-PA-18-200,
author = {Buizza, R. and Brönnimann, S. and Haimberger, L. and Laloyaux, P. and Martin, M.J. and Fuentes , M. and Alonso-Balmaseda, M. and Becker, A. and Blaschek, M. and Dahlgren, P. and de Boisseson, E. and Dee, D. and Doutriaux-Boucher, M. and Feng, X. and John, V.O. and Haines, K. and Jourdain, S. and Kosaka, Y. and Lea, D. and Lemarié, F. and Mayer, M. and Messina, P. and Perruche, C. and Peylin, P. and Pullainen, J. and Rayner, N. and Rustemeier, E. and Schepers, D. and Saunders, R. and Schulz, J. and Sterin, A. and Stichelberger, S. and Storto, A. and Testut, C.-E. and Valente, M.-A. and Vidard, A. and Vuichard, N. and Weaver, A.T. and While, J. and Ziese, M. },
title = {The EU-FP7 ERA-CLIM2 Project Contribution to Advancing Science and Production of Earth System Climate Reanalyses},
year = {2018},
volume = {99},
pages = {1003--1014},
doi = {10.1175/BAMS-D-17-0199.1},
journal = {Bulletin of the American Meteorological Society},
abstract = {The European Reanalysis of Global Climate Observations 2 (ERA-CLIM2) is a European Union Seventh Framework Project started in January 2014 and due to be completed in December 2017. It aims to produce coupled reanalyses, which are physically consistent datasets describing the evolution of the global atmosphere, ocean, land surface, cryosphere, and the carbon cycle. ERA-CLIM2 has contributed to advancing the capacity for producing state-of-the-art climate reanalyses that extend back to the early twentieth century. ERA-CLIM2 has led to the generation of the first European ensemble of coupled ocean, sea ice, land, and atmosphere reanalyses of the twentieth century. The project has funded work to rescue and prepare observations and to advance the data-assimilation systems required to generate operational reanalyses, such as the ones planned by the European Union Copernicus Climate Change Service. This paper summarizes the main goals of the project, discusses some of its main areas of activities, and presents some of its key results.},
pdf = {https://doi.org/10.1175/BAMS-D-17-0199.1}}
Guillet, O., Weaver, A.T., Vasseur, X., Michel, M., Gratton, S. and Gürol, S. (2018) Modelling spatially correlated observation errors in variational data assimilation using a diffusion operator on an unstructured mesh, Quarterly Journal of the Royal Meteorological Society
[bibtex]
@ARTICLE{AR-PA-18-201,
author = {Guillet, O. and Weaver, A.T. and Vasseur, X. and Michel, M. and Gratton, S. and Gürol, S. },
title = {Modelling spatially correlated observation errors in variational data assimilation using a diffusion operator on an unstructured mesh},
year = {2018},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Weaver, A.T., Tshimanga, J. and Piacentini, A (2016) Correlation operators based on an implicitly formulated diffusion equation solved with the Chebyshev iteration, Quarterly Journal of the Royal Meteorological Society, 142, pp. 455 - 471, doi: 10.1002/qj.2664
[bibtex]
[url] [pdf]
@ARTICLE{AR-PA-16-27633,
author = {Weaver, A.T. and Tshimanga, J. and Piacentini, A },
title = {Correlation operators based on an implicitly formulated diffusion equation solved with the Chebyshev iteration},
year = {2016},
volume = {142},
pages = {455 - 471},
doi = {10.1002/qj.2664},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://doi.org/10.1002/qj.2664 },
url = {http://dx.doi.org/10.1002/qj.2664}}
Stammer, D., Balmaseda, M.A., Heimbach, P., Köhl, A. and Weaver, A.T. (2016) Ocean Data Assimilation in Support of Climate Applications, Annual Review of Marine Science, 8 (1) , pp. 491-518, doi: 10.1146/annurev-marine-122414-034113
[bibtex] [pdf]
@ARTICLE{AR-PA-16-231,
author = {Stammer, D. and Balmaseda, M.A. and Heimbach, P. and Köhl, A. and Weaver, A.T. },
title = {Ocean Data Assimilation in Support of Climate Applications},
year = {2016},
number = {1},
volume = {8},
pages = {491-518},
doi = {10.1146/annurev-marine-122414-034113},
journal = {Annual Review of Marine Science},
abstract = {Ocean data assimilation brings together observations with known dynamics encapsulated in a circulation model to describe the time-varying ocean circulation. Its applications are manifold, ranging from marine and ecosystem forecasting to climate prediction and studies of the carbon cycle. Here, we address only climate applications, which range from improving our understanding of ocean circulation to estimating initial or boundary conditions and model parameters for ocean and climate forecasts. Because of differences in underlying methodologies, data assimilation products must be used judiciously and selected according to the specific purpose, as not all related inferences would be equally reliable. Further advances are expected from improved models and methods for estimating and representing error information in data assimilation systems. Ultimately, data assimilation into coupled climate system components is needed to support ocean and climate services. However, maintaining the infrastructure and expertise for sustained data assimilation remains challenging.},
pdf = {https://doi.org/10.1146/annurev-marine-122414-034113}}
Waters, J., Lea, D.J., Martin, M., Mirouze, I., Weaver, A.T. and While, J. (2015) Implementing a variational data assimilation system in an operational 1/4 degree global ocean model, Quarterly Journal of the Royal Meteorological Society, 141, pp. 333 - 349, ISSN 1477-870X, doi: 10.1002/qj.2388
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-15-22443,
author = {Waters, J. and Lea, D.J. and Martin, M. and Mirouze, I. and Weaver, A.T. and While, J. },
title = {Implementing a variational data assimilation system in an operational 1/4 degree global ocean model},
year = {2015},
volume = {141},
pages = {333 - 349},
issn = {1477-870X},
doi = {10.1002/qj.2388},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/06/qjrms2388.pdf},
url = {http://dx.doi.org/10.1002/qj.2388}}
Martin, M., Balmaseda, M.A., Bertino, L., Brasseur, P., Brassington, G., Cummings, J., Fujii, Y., Lea, D.J., Lellouche, J.-M., Mogensen, K., Oke, P., Smith, G.C., Testut, C.E., Waagbo, G.A., Waters, J. and Weaver, A.T. (2015) Status and future of data assimilation in operational oceanography, Journal of Operational Oceanography, 8 (S1) , pp. s28-s48
[bibtex]
@ARTICLE{AR-PA-15-27898,
author = {Martin, M. and Balmaseda, M.A. and Bertino, L. and Brasseur, P. and Brassington, G. and Cummings, J. and Fujii, Y. and Lea, D.J. and Lellouche, J.-M. and Mogensen, K. and Oke, P. and Smith, G.C. and Testut, C.E. and Waagbo, G.A. and Waters, J. and Weaver, A.T. },
title = {Status and future of data assimilation in operational oceanography},
year = {2015},
number = {S1},
volume = {8},
pages = {s28-s48},
journal = {Journal of Operational Oceanography}}
Gürol, S., Weaver, A.T., Moore, A.M., Piacentini, A, Arango, H.G. and Gratton, S. (2014) B-preconditioned minimization algorithms for variational data assimilation with the dual formulation, Quarterly Journal of the Royal Meteorological Society, 140 (679) , pp. 539 - 556, ISSN 1477-870X, doi: 10.1002/qj.2150
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-14-22016,
author = {Gürol, S. and Weaver, A.T. and Moore, A.M. and Piacentini, A and Arango, H.G. and Gratton, S. },
title = {B-preconditioned minimization algorithms for variational data assimilation with the dual formulation},
year = {2014},
number = {679},
volume = {140},
pages = {539 - 556},
issn = {1477-870X},
doi = {10.1002/qj.2150},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/06/2150_ftp.pdf},
url = {http://onlinelibrary.wiley.com/doi/10.1002/qj.2150/abstract}}
Martin, M., Balmaseda, M.A., Bertino, L., Brasseur, P., Brassington, G., Cummings, J., Fujii, Y., Lea, D.J., Lellouche, J.-M., Mogensen, K., Oke, P., Smith, G.C., Testut, C.-E., Waagbo, G.A., Waters, J. and Weaver, A.T. (2014) Status and future of data assimilation in operational oceanography, Journal of Operational Oceanography, 8 (S1 - GODAE OceanView Part 1) , pp. s28-s48, ISSN 1755-8778, doi: 10.1080/1755876X.2015.1022055
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-14-22127,
author = {Martin, M. and Balmaseda, M.A. and Bertino, L. and Brasseur, P. and Brassington, G. and Cummings, J. and Fujii, Y. and Lea, D.J. and Lellouche, J.-M. and Mogensen, K. and Oke, P. and Smith, G.C. and Testut, C.-E. and Waagbo, G.A. and Waters, J. and Weaver, A.T. },
title = {Status and future of data assimilation in operational oceanography},
year = {2014},
number = {S1 - GODAE OceanView Part 1},
volume = {8},
pages = {s28-s48},
issn = {1755-8778},
doi = {10.1080/1755876X.2015.1022055},
journal = {Journal of Operational Oceanography},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/06/1755876X.2015.pdf},
url = {http://www.tandfonline.com/doi/abs/10.1080/1755876X.2015.1022055}}
Balmaseda, M.A., Mogensen, K. and Weaver, A.T. (2013) Evaluation of the ECMWF ocean reanalysis system ORAS4, Quarterly Journal of the Royal Meteorological Society, 139 (674) , pp. 1132 - 1161, ISSN 1477-870X, doi: 10.1002/qj.2063
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-13-21818,
author = {Balmaseda, M.A. and Mogensen, K. and Weaver, A.T. },
title = {Evaluation of the ECMWF ocean reanalysis system ORAS4},
year = {2013},
number = {674},
volume = {139},
pages = {1132 - 1161},
issn = {1477-870X},
doi = {10.1002/qj.2063},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/06/GLOBC-Balmaseda_et_al_RMetS_2013.pdf},
url = {http://dx.doi.org/10.1002/qj.2063}}
Weaver, A.T. and Mirouze, I. (2013) On the diffusion equation and its application to isotropic and anisotropic correlation modelling in variational assimilation, Quarterly Journal of the Royal Meteorological Society, 139 (670) , pp. 242 - 260, ISSN 1477-870X, doi: 10.1002/qj.1955
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-13-22455,
author = {Weaver, A.T. and Mirouze, I. },
title = {On the diffusion equation and its application to isotropic and anisotropic correlation modelling in variational assimilation},
year = {2013},
number = {670},
volume = {139},
pages = {242 - 260},
issn = {1477-870X},
doi = {10.1002/qj.1955},
journal = {Quarterly Journal of the Royal Meteorological Society},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/06/GLOBC-Weaver_Mirouze_RMetS_2013.pdf},
url = {http://dx.doi.org/10.1002/qj.1955}}
Corre, L., Terray, L., Balmaseda, M., Ribes, A. and Weaver, A.T. (2012) Can oceanic reanalyses be used to assess recent anthropogenic changes and low-frequency internal variability of upper ocean temperature ?, Climate Dynamics, 38 (5-6) , pp. 877 - 896, ISSN 0930-7575, doi: 10.1007/s00382-010-0950-8
[bibtex]
[url] [pdf]
@ARTICLE{AR-CMGC-12-21927,
author = {Corre, L. and Terray, L. and Balmaseda, M. and Ribes, A. and Weaver, A.T. },
title = {Can oceanic reanalyses be used to assess recent anthropogenic changes and low-frequency internal variability of upper ocean temperature ?},
year = {2012},
number = {5-6},
volume = {38},
pages = {877 - 896},
issn = {0930-7575},
doi = {10.1007/s00382-010-0950-8},
journal = {Climate Dynamics},
pdf = {https://cerfacs.fr/wp-content/uploads/2016/05/GLOBC-Corre_et_al_CLIMDYN_2012.pdf},
url = {http://dx.doi.org/10.1007/s00382-010-0950-8}}
Moore, A.M., Arango, H.G., Broquet, G., Powell, B.S., Weaver, A.T. and Zavala-Garay, J. (2011) The regional ocean modelling system (roms) 4-dimensional variational data assimilation systems, part I - system overview and formulation, Progress in Oceanography, 91, pp. 34 - 49
[bibtex]
@ARTICLE{AR-CMGC-11-22168,
author = {Moore, A.M. and Arango, H.G. and Broquet, G. and Powell, B.S. and Weaver, A.T. and Zavala-Garay, J. },
title = {The regional ocean modelling system (roms) 4-dimensional variational data assimilation systems, part I - system overview and formulation},
year = {2011},
volume = {91},
pages = {34 - 49},
journal = {Progress in Oceanography}}
Weaver, A.T. and Mirouze, I. (2011) On the diffusion equation and its application to isotropic and anisotropic correlation modelling in variational assimilation, Quarterly Journal of the Royal Meteorological Society
[bibtex]
@ARTICLE{AR-CMGC-11-22456,
author = {Weaver, A.T. and Mirouze, I. },
title = {On the diffusion equation and its application to isotropic and anisotropic correlation modelling in variational assimilation},
year = {2011},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Lee, T., Awaji, T., Balmaseda, M.A., Ferry, N., Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D. and Weaver, A.T. (2010) Consistency and fidelity of indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products, Dynamics of Atmospheres and Oceans, 50, pp. 201 - 223
[bibtex]
@ARTICLE{AR-CMGC-10-22086,
author = {Lee, T. and Awaji, T. and Balmaseda, M.A. and Ferry, N. and Fujii, Y. and Fukumori, I. and Giese, B. and Heimbach, P. and Köhl, A. and Masina, S. and Remy, E. and Rosati, A. and Schodlok, M. and Stammer, D. and Weaver, A.T. },
title = {Consistency and fidelity of indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products},
year = {2010},
volume = {50},
pages = {201 - 223},
journal = {Dynamics of Atmospheres and Oceans}}
Mirouze, I. and Weaver, A.T. (2010) Representation of correlation functions in variational assimilation using an implicit diffusion operator, Quarterly Journal of the Royal Meteorological Society, 136, pp. 1421 - 1443
[bibtex]
@ARTICLE{AR-CMGC-10-22159,
author = {Mirouze, I. and Weaver, A.T. },
title = {Representation of correlation functions in variational assimilation using an implicit diffusion operator},
year = {2010},
volume = {136},
pages = {1421 - 1443},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Cummings, J., Bertino, L., Brasseur, P., Fukumori, I., Kamachi, M., Martin, M., Oke, P., Testut, C.-E., Verron, J. and Weaver, A.T. (2009) Ocean data assimilation systems for GODAE, 22, pp. 96 - 109
[bibtex]
@article{AR-CMGC-09-21935,
author = {Cummings, J. and Bertino, L. and Brasseur, P. and Fukumori, I. and Kamachi, M. and Martin, M. and Oke, P. and Testut, C.-E. and Verron, J. and Weaver, A.T. },
title = {Ocean data assimilation systems for GODAE},
year = {2009},
volume = {22},
pages = {96 - 109}}
Daget, N., Weaver, A.T. and Balmaseda, M.A. (2009) Ensemble estimation of background-error variances in a three-dimensional variational data assimilation system for the global ocean, Quarterly Journal of the Royal Meteorological Society, 135, pp. 1071 - 1094
[bibtex]
@ARTICLE{AR-CMGC-09-21957,
author = {Daget, N. and Weaver, A.T. and Balmaseda, M.A. },
title = {Ensemble estimation of background-error variances in a three-dimensional variational data assimilation system for the global ocean},
year = {2009},
volume = {135},
pages = {1071 - 1094},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Lee, T., Awaji, T., Balmaseda, M.A., Ferry, N., Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D. and Weaver, A.T. (2009) Consistency and fidelity of Indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products., Dynamics of Atmospheres and Oceans, In press
[bibtex]
@ARTICLE{AR-CMGC-09-22087,
author = {Lee, T. and Awaji, T. and Balmaseda, M.A. and Ferry, N. and Fujii, Y. and Fukumori, I. and Giese, B. and Heimbach, P. and Köhl, A. and Masina, S. and Remy, E. and Rosati, A. and Schodlok, M. and Stammer, D. and Weaver, A.T. },
title = {Consistency and fidelity of Indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products.},
year = {2009},
volume = {In press},
journal = {Dynamics of Atmospheres and Oceans}}
Mirouze, I. and Weaver, A.T. (2009) Representation of correlation functions in variational assimilation using an implicit diffusion equation, Quarterly Journal of the Royal Meteorological Society, Submitted
[bibtex]
@ARTICLE{AR-CMGC-09-22160,
author = {Mirouze, I. and Weaver, A.T. },
title = {Representation of correlation functions in variational assimilation using an implicit diffusion equation},
year = {2009},
volume = {Submitted},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Mogensen, K., Balmaseda, M.A., Weaver, A.T., Martin, M. and Vidard, A. (2009) NEMOVAR: a variational data assimilation system for the NEMO ocean model, ECMWF Technical Memorandum, Number 120
[bibtex]
@ARTICLE{AR-CMGC-09-22163,
author = {Mogensen, K. and Balmaseda, M.A. and Weaver, A.T. and Martin, M. and Vidard, A. },
title = {NEMOVAR: a variational data assimilation system for the NEMO ocean model},
year = {2009},
volume = {Number 120},
journal = {ECMWF Technical Memorandum}}
Sévellec, F., Huck, T., Ben Jelloul, M., Grima, N., Vialard, J. and Weaver, A.T. (2008) Optimal surface salinity perturbations of the meridional overturning and heat transport in a global ocean general circulation model, Journal of Physical Oceanography, 38, pp. 2739 - 2754
[bibtex]
@ARTICLE{AR-CMGC-08-22301,
author = {Sévellec, F. and Huck, T. and Ben Jelloul, M. and Grima, N. and Vialard, J. and Weaver, A.T. },
title = {Optimal surface salinity perturbations of the meridional overturning and heat transport in a global ocean general circulation model},
year = {2008},
volume = {38},
pages = {2739 - 2754},
journal = {Journal of Physical Oceanography}}
Tshimanga, J., Gratton, S., Weaver, A.T. and Sartenaer, A. (2008) Limited-memory preconditioners with application to incremental four-dimensional variational data assimilation, Quarterly Journal of the Royal Meteorological Society, 134, pp. 753 - 771
[bibtex]
@ARTICLE{AR-CMGC-08-22373,
author = {Tshimanga, J. and Gratton, S. and Weaver, A.T. and Sartenaer, A. },
title = {Limited-memory preconditioners with application to incremental four-dimensional variational data assimilation},
year = {2008},
volume = {134},
pages = {753 - 771},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Moore, A.M., Zavala-Garay, J., Tang, Y., Kleeman, R., Weaver, A.T., Vialard, J., Sahami, K., Anderson, D.L.T. and Fisher, M. (2006) On the low-dimensionality of ENSO as evidenced by the optimal forcing patterns of coupled models, Journal of Climate, 19, pp. 4683 - 4699
[bibtex]
@ARTICLE{AR-CMGC-06-22173,
author = {Moore, A.M. and Zavala-Garay, J. and Tang, Y. and Kleeman, R. and Weaver, A.T. and Vialard, J. and Sahami, K. and Anderson, D.L.T. and Fisher, M. },
title = {On the low-dimensionality of ENSO as evidenced by the optimal forcing patterns of coupled models},
year = {2006},
volume = {19},
pages = {4683 - 4699},
journal = {Journal of Climate}}
Moore, A.M., Zavala-Garay, J., Tang, Y., Kleeman, R., Weaver, A.T., Vialard, J., Sahami, K., Anderson, D.L.T. and Fisher, M. (2006) On the low-dimensionality of ENSO as evidenced by the optimal forcing patterns of coupled models, Journal of Climate, to appear
[bibtex]
@ARTICLE{AR-CMGC-06-22174,
author = {Moore, A.M. and Zavala-Garay, J. and Tang, Y. and Kleeman, R. and Weaver, A.T. and Vialard, J. and Sahami, K. and Anderson, D.L.T. and Fisher, M. },
title = {On the low-dimensionality of ENSO as evidenced by the optimal forcing patterns of coupled models},
year = {2006},
volume = {to appear},
journal = {Journal of Climate}}
Weaver, A.T., Deltel, C., Machu, E., Ricci, S. and Daget, N. (2006) A multivariate balance operator for variational ocean data assimilation, Quarterly Journal of the Royal Meteorological Society, 131, pp. 3605 - 3626
[bibtex]
@ARTICLE{AR-CMGC-06-22454,
author = {Weaver, A.T. and Deltel, C. and Machu, E. and Ricci, S. and Daget, N. },
title = {A multivariate balance operator for variational ocean data assimilation},
year = {2006},
volume = {131},
pages = {3605 - 3626},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Ricci, S., Weaver, A.T., Vialard, J. and Rogel, P. (2005) Incorporating state-dependent temperature-salinity constraints in the background-error covariance of variational ocean data assimilation, Monthly Weather Review, 133,, pp. 317 - 338
[bibtex]
@ARTICLE{AR-CMGC-05-22264,
author = {Ricci, S. and Weaver, A.T. and Vialard, J. and Rogel, P. },
title = {Incorporating state-dependent temperature-salinity constraints in the background-error covariance of variational ocean data assimilation},
year = {2005},
volume = {133,},
pages = {317 - 338},
journal = {Monthly Weather Review}}
Rogel, P., Weaver, A.T., Daget, N., Ricci, S. and Machu, E. (2005) Ensembles of global ocean analyses for seasonal climate prediction: impact of temperature assimilation, 57A, pp. 375 - 386
[bibtex]
@ARTICLE{AR-CMGC-05-22293,
author = {Rogel, P. and Weaver, A.T. and Daget, N. and Ricci, S. and Machu, E. },
title = {Ensembles of global ocean analyses for seasonal climate prediction: impact of temperature assimilation},
year = {2005},
volume = {57A},
pages = {375 - 386}}
Weaver, A.T., Deltel, C., Machu, E. and Ricci, S. (2005) A multivariate balance operator for variational ocean data assimilation, Quarterly Journal of the Royal Meteorological Society, submitted
[bibtex]
@ARTICLE{AR-CMGC-05-22453,
author = {Weaver, A.T. and Deltel, C. and Machu, E. and Ricci, S. },
title = {A multivariate balance operator for variational ocean data assimilation},
year = {2005},
volume = {submitted},
journal = {Quarterly Journal of the Royal Meteorological Society}}
Tang, Y., Kleeman, R., Moore, A.M., Vialard, J. and Weaver, A.T. (2004) An offline, numerically efficient initialization scheme in an oceanic general circulation model for el Nino-southern oscillation prediction, Journal of Geophysical Research, 109 (C5)
[bibtex]
@ARTICLE{AR-CMGC-04-22326,
author = {Tang, Y. and Kleeman, R. and Moore, A.M. and Vialard, J. and Weaver, A.T. },
title = {An offline, numerically efficient initialization scheme in an oceanic general circulation model for el Nino-southern oscillation prediction},
year = {2004},
volume = {109 (C5)},
journal = {Journal of Geophysical Research}}
Vossepoel, F., Weaver, A.T., Vialard, J. and Delecluse, P. (2004) Adjustment of near-equatorial wind stress with four-dimensional variational data assimilation in a model of the Pacific ocean, Monthly Weather Review, 132, pp. 2070 - 2083
[bibtex]
@ARTICLE{AR-CMGC-04-22441,
author = {Vossepoel, F. and Weaver, A.T. and Vialard, J. and Delecluse, P. },
title = {Adjustment of near-equatorial wind stress with four-dimensional variational data assimilation in a model of the Pacific ocean},
year = {2004},
volume = {132},
pages = {2070 - 2083},
journal = {Monthly Weather Review}}
Moore, A.M., Vialard, J., Weaver, A.T., Anderson, D.L.T., Kleeman, R. and Johnson, J.R. (2003) The role of air-sea interaction in controlling the optimal perturbations of low-frequency tropical coupled ocean-atmosphere modes., Journal of Climate, 16, pp. 951 - 968
[bibtex]
@ARTICLE{AR-CMGC-03-22170,
author = {Moore, A.M. and Vialard, J. and Weaver, A.T. and Anderson, D.L.T. and Kleeman, R. and Johnson, J.R. },
title = {The role of air-sea interaction in controlling the optimal perturbations of low-frequency tropical coupled ocean-atmosphere modes.},
year = {2003},
volume = {16},
pages = {951 - 968},
journal = {Journal of Climate}}
Ricci, S., Weaver, A.T., Vialard, J. and Rogel, P. (2003) Incorporating state-dependent temperature-salinity constraints in the background-error covariance of variational ocean data assimilation, Monthly Weather Review
[bibtex]
@ARTICLE{AR-CMGC-03-22265,
author = {Ricci, S. and Weaver, A.T. and Vialard, J. and Rogel, P. },
title = {Incorporating state-dependent temperature-salinity constraints in the background-error covariance of variational ocean data assimilation},
year = {2003},
journal = {Monthly Weather Review}}
Tang, Y., Kleeman, R., Moore, A.M., Weaver, A.T. and Vialard, J. (2003) The role of air-sea interaction in controlling the optimal perturbations of low-frequency tropical coupled ocean-atmosphere modes., Geophysical Research Letters, 30(13)
[bibtex]
@ARTICLE{AR-CMGC-03-22327,
author = {Tang, Y. and Kleeman, R. and Moore, A.M. and Weaver, A.T. and Vialard, J. },
title = {The role of air-sea interaction in controlling the optimal perturbations of low-frequency tropical coupled ocean-atmosphere modes.},
year = {2003},
volume = {30(13)},
journal = {Geophysical Research Letters}}
Tang, Y., Kleeman, R., Moore, A.M., Weaver, A.T. and Vialard, J. (2003) The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled modes geophys. res. lett., 30(13), pp. 1694, doi: 10.1029/2003GLO1766
[bibtex]
@article{AR-CMGC-03-22328,
author = {Tang, Y. and Kleeman, R. and Moore, A.M. and Weaver, A.T. and Vialard, J. },
title = {The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled modes geophys. res. lett.},
year = {2003},
volume = {30(13)},
pages = {1694},
doi = {10.1029/2003GLO1766}}
Vialard, J., Weaver, A.T., Anderson, D.L.T. and Delecluse, P. (2003) Three-and-four dimensional variational assimilation with an ocean general circulation model of the tropical Pacific ocean. part 2: physical validation., Monthly Weather Review, 131, pp. 1379 - 1395
[bibtex]
@ARTICLE{AR-CMGC-03-22432,
author = {Vialard, J. and Weaver, A.T. and Anderson, D.L.T. and Delecluse, P. },
title = {Three-and-four dimensional variational assimilation with an ocean general circulation model of the tropical Pacific ocean. part 2: physical validation.},
year = {2003},
volume = {131},
pages = {1379 - 1395},
journal = {Monthly Weather Review}}
Vossepoel, F., Weaver, A.T., Vialard, J. and Delecluse, P. (2003) Adjustment of near-equatorial wind stress with four-dimensional variational data assimilation in a model of the Pacific ocean, Monthly Weather Review
[bibtex]
@ARTICLE{AR-CMGC-03-22442,
author = {Vossepoel, F. and Weaver, A.T. and Vialard, J. and Delecluse, P. },
title = {Adjustment of near-equatorial wind stress with four-dimensional variational data assimilation in a model of the Pacific ocean},
year = {2003},
journal = {Monthly Weather Review}}
Weaver, A.T., Vialard, J. and Anderson, D.L.T. (2003) Three-and four-dimensional variational assimilation with an ocean general circulation model of the tropical Pacific ocean. part 1: formulation, internal diagnostics and consistency checks., Monthly Weather Review, 131, pp. 1360 - 1378
[bibtex]
@ARTICLE{AR-CMGC-03-22462,
author = {Weaver, A.T. and Vialard, J. and Anderson, D.L.T. },
title = {Three-and four-dimensional variational assimilation with an ocean general circulation model of the tropical Pacific ocean. part 1: formulation, internal diagnostics and consistency checks.},
year = {2003},
volume = {131},
pages = {1360 - 1378},
journal = {Monthly Weather Review}}
Moore, A.M., Vialard, J., Weaver, A.T., Anderson, D.L.T., Kleeman, R. and Johnson, J.R. (2002) The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled ocean-atmosphere modes, Submitted
[bibtex]
@article{AR-CMGC-02-22171,
author = {Moore, A.M. and Vialard, J. and Weaver, A.T. and Anderson, D.L.T. and Kleeman, R. and Johnson, J.R. },
title = {The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled ocean-atmosphere modes},
year = {2002},
volume = {Submitted}}
Vialard, J., Weaver, A.T., Anderson, D.L.T. and Delecluse, P. (2002) Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean. part 2:
physical validation, Submitted
[bibtex]
@article{AR-CMGC-02-22433,
author = {Vialard, J. and Weaver, A.T. and Anderson, D.L.T. and Delecluse, P. },
title = {Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean. part 2:
physical validation},
year = {2002},
volume = {Submitted}}
Weaver, A.T., Vialard, J., Anderson, D.L.T. and Delecluse, P. (2002) Three-and-four dimensional variational assimilation with an ocean general circulation model of the tropical pacific ocean. part 1:formulation, internal diagnostics and consistency checks, Monthly Weather Review, Submitted
[bibtex]
@ARTICLE{AR-CMGC-02-22464,
author = {Weaver, A.T. and Vialard, J. and Anderson, D.L.T. and Delecluse, P. },
title = {Three-and-four dimensional variational assimilation with an ocean general circulation model of the tropical pacific ocean. part 1:formulation, internal diagnostics and consistency checks},
year = {2002},
volume = {Submitted},
journal = {Monthly Weather Review}}
Weaver, A.T. and Courtier, P. (2001) Correlation modelling on the sphere using a generalized diffusionequation, Quarterly Journal of the Royal Meteorological Society, 127, pp. 1815 - 1846
[bibtex]
@ARTICLE{AR-CMGC-01-22451,
author = {Weaver, A.T. and Courtier, P. },
title = {Correlation modelling on the sphere using a generalized diffusionequation},
year = {2001},
volume = {127},
pages = {1815 - 1846},
journal = {Quarterly Journal of the Royal Meteorological Society}}
@CONFERENCE
Destouches, M., Mycek, P., Briant, J., Gürol, S., Weaver, A.T., Gratton, S. and Simon, E. (2022) Multilevel Monte Carlo estimation of background error covariances in ensemble variational data assimilation, EGU General Assembly, Vienna, Austria and online, EGU22-336., 5 2022, doi: 10.5194/egusphere-egu22-336
[bibtex]
[url]
@CONFERENCE{PR-PA-22-64,
author = {Destouches, M. and Mycek, P. and Briant, J. and Gürol, S. and Weaver, A.T. and Gratton, S. and Simon, E. },
title = {Multilevel Monte Carlo estimation of background error covariances in ensemble variational data assimilation},
year = {2022},
month = {5},
booktitle = {EGU General Assembly, Vienna, Austria and online, EGU22-336},
doi = {10.5194/egusphere-egu22-336},
url = {https://meetingorganizer.copernicus.org/EGU22/EGU22-336.html}}
Weaver, A.T. (2018) Méthodes variationnelles et ensemblistes pour l’océanographie, Séminaire en l’honneur d’Olivier Talagrand et Gérald Desroziers, Météo-France, Toulouse, 15-16 May, 2018., 5 2018
[bibtex]
@CONFERENCE{PR-PA-18-240,
author = {Weaver, A.T. },
title = {Méthodes variationnelles et ensemblistes pour l’océanographie},
year = {2018},
month = {5},
booktitle = {Séminaire en l’honneur d’Olivier Talagrand et Gérald Desroziers, Météo-France, Toulouse, 15-16 May, 2018},
keywords = {invite}}
Weaver, A.T. (2018) Hybrid ensemble variational methods for ocean problems, Marine Data Assimilation Workshop, Mercator-Océan International, 5-6 September, 2018., 9 2018
[bibtex]
@CONFERENCE{PR-PA-18-241,
author = {Weaver, A.T. },
title = {Hybrid ensemble variational methods for ocean problems},
year = {2018},
month = {9},
booktitle = {Marine Data Assimilation Workshop, Mercator-Océan International, 5-6 September, 2018},
keywords = {invite}}
Weaver, A.T. (2018) Characterizing and modelling backround error, Earth System Assimilation, ECMWF Seminar, 10-13 September, 2018., 9 2018
[bibtex]
@CONFERENCE{PR-PA-18-242,
author = {Weaver, A.T. },
title = {Characterizing and modelling backround error},
year = {2018},
month = {9},
booktitle = {Earth System Assimilation, ECMWF Seminar, 10-13 September, 2018},
keywords = {invite}}
Weaver, A.T. (2017) Recent advances in diffusion-based correlation modelling, Minisymposium on Current Topics in Uncertainty Characterization, UNCECOMP-2017: Thematic conference of the European Community on Computational Methods in Applied Sciences (ECCOMAS), Rhodes, Greece, 15–17 June 2017., 6 2017
[bibtex]
@CONFERENCE{PR-PA-17-331,
author = {Weaver, A.T. },
title = {Recent advances in diffusion-based correlation modelling},
year = {2017},
month = {6},
booktitle = {Minisymposium on Current Topics in Uncertainty Characterization, UNCECOMP-2017: Thematic conference of the European Community on Computational Methods in Applied Sciences (ECCOMAS), Rhodes, Greece, 15–17 June 2017},
keywords = {invite}}
Weaver, A.T. (2016) Global ocean data assimilation, Météorologie: de l'atmosphère à l'espace - 2. Assimilation de données, Météo-France, Toulouse, 8-9 November 2016., 11 2016
[bibtex]
@CONFERENCE{PR-PA-16-386,
author = {Weaver, A.T. },
title = {Global ocean data assimilation},
year = {2016},
month = {11},
booktitle = {Météorologie: de l'atmosphère à l'espace - 2. Assimilation de données, Météo-France, Toulouse, 8-9 November 2016},
keywords = {invite}}
Weaver, A.T. (2016) Parallel Aspects of Diffusion-Based Correlation Operators in Ensemble-Variational Data Assimilation, 17th SIAM Conference on Parallel Processing for Scientific Computing, Paris, France, April 12-15, 2016., 4 2016
[bibtex]
@CONFERENCE{PR-PA-16-391,
author = {Weaver, A.T. },
title = {Parallel Aspects of Diffusion-Based Correlation Operators in Ensemble-Variational Data Assimilation},
year = {2016},
month = {4},
booktitle = {17th SIAM Conference on Parallel Processing for Scientific Computing, Paris, France, April 12-15, 2016},
keywords = {invite}}
Weaver, A.T. (2016) Developments in ensemble-variational data assimilation for the global ocean, Workshop on Blueprints for Next-Generation Data Assimilation Systems, NCAR, Boulder, Colorado, USA, 8-10 March 2016., 3 2016
[bibtex]
@CONFERENCE{PR-PA-16-393,
author = {Weaver, A.T. },
title = {Developments in ensemble-variational data assimilation for the global ocean},
year = {2016},
month = {3},
booktitle = {Workshop on Blueprints for Next-Generation Data Assimilation Systems, NCAR, Boulder, Colorado, USA, 8-10 March 2016},
keywords = {invite}}
Weaver, A.T. (2015) Correlation operators based on the iterative solution of an implicitly formulated diffusion equation, EGU - session on Inverse problems, data assimilation, coupled initialization, impact of initial and model errors, and predictability. Vienna, Austria, 12-17 April 2015., 4 2015
[bibtex]
@CONFERENCE{PR-PA-15-81,
author = {Weaver, A.T. },
title = {Correlation operators based on the iterative solution of an implicitly formulated diffusion equation},
year = {2015},
month = {4},
booktitle = {EGU - session on Inverse problems, data assimilation, coupled initialization, impact of initial and model errors, and predictability. Vienna, Austria, 12-17 April 2015},
keywords = {invite}}
Weaver, A.T. (2015) Numerical aspects of correlation modelling and localization using diffusion operators (with application to global ocean variational data assimilation), International Workshop on Theoretical Aspects of Ensemble Data Assimilation for The Earth System, Les Houches, France. April 5 - 10., 4 2015
[bibtex]
@CONFERENCE{PR-PA-15-82,
author = {Weaver, A.T. },
title = {Numerical aspects of correlation modelling and localization using diffusion operators (with application to global ocean variational data assimilation)},
year = {2015},
month = {4},
booktitle = {International Workshop on Theoretical Aspects of Ensemble Data Assimilation for The Earth System, Les Houches, France. April 5 - 10},
keywords = {invite}}
Ricci, S., Piacentini, A, Weaver, A.T., Ata, R. and Goutal, N. (2014) A variational data assimilation algorithm to estimate salinity in the Berre lagoon with TELEMAC, Turin, Italy 2014
[bibtex]
@CONFERENCE{PR-CMGC-14-22260,
author = {Ricci, S. and Piacentini, A and Weaver, A.T. and Ata, R. and Goutal, N. },
title = {A variational data assimilation algorithm to estimate salinity in the Berre lagoon with TELEMAC},
year = {2014},
address = {Turin, Italy}}
Ricci, S., Piacentini, A, Weaver, A.T., Ata, R. and Goutal, N. (2014) Variational data assimilation with TELEMAC. Proof of concept for model state correction on the Berre lagoon 3d-model?, 11th International conference on hydro informatics., New York City, USA 2014
[bibtex]
@CONFERENCE{PR-CMGC-14-22261,
author = {Ricci, S. and Piacentini, A and Weaver, A.T. and Ata, R. and Goutal, N. },
title = {Variational data assimilation with TELEMAC. Proof of concept for model state correction on the Berre lagoon 3d-model?},
year = {2014},
booktitle = {11th International conference on hydro informatics},
address = {New York City, USA}}
Weaver, A.T. (2014) Examples of representing observation error correlations in variational ocean data assimilation, ESA International Workshop on Correlated Observation Errors in Data Assimilation, University of Reading, 23–24 April 2014, Reading, UK., 4 2014
[bibtex]
@CONFERENCE{PR-CMGC-14-29,
author = {Weaver, A.T. },
title = {Examples of representing observation error correlations in variational ocean data assimilation},
year = {2014},
month = {4},
booktitle = {ESA International Workshop on Correlated Observation Errors in Data Assimilation, University of Reading, 23–24 April 2014, Reading, UK},
keywords = {invite}}
Gürol, S., Weaver, A.T., Gratton, S., Moore, A.M., Piacentini, A and Arango, H.G. (2013) B-preconditioned minimization algorithm for variational assimilation with the dual formulation 6th WMO international symposium on data assimilation, NCEP, 7-11 october, Washington, USA 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22014,
author = {Gürol, S. and Weaver, A.T. and Gratton, S. and Moore, A.M. and Piacentini, A and Arango, H.G. },
title = {B-preconditioned minimization algorithm for variational assimilation with the dual formulation},
year = {2013},
organization = {6th WMO international symposium on data assimilation, NCEP, 7-11 october},
address = {Washington, USA}}
Moore, A.M., Edwards, C., Fiechter, J., Drake, P., Arango, H., Neveu, E., Weaver, A.T. and Gürol, S. (2013) A 4d-var analysis system for the california current: a prototypefor an operational regional ocean data assimilation system., Data assimilation for atmospheric, oceanic and hydrologic applicationsvol ii, s.k park and l. xu (eds.) springer. 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22169,
author = {Moore, A.M. and Edwards, C. and Fiechter, J. and Drake, P. and Arango, H. and Neveu, E. and Weaver, A.T. and Gürol, S. },
title = {A 4d-var analysis system for the california current: a prototypefor an operational regional ocean data assimilation system.},
year = {2013},
booktitle = {Data assimilation for atmospheric, oceanic and hydrologic applicationsvol ii, s.k park and l. xu (eds.) springer}}
Ricci, S., Piacentini, A, Weaver, A.T., Ata, R. and Goutal, N. (2013) A variational data assimilation algorithm to estimate the salinity for the Berre lagoon with TELEMAC3D XXth TELEMAC-MASCARET User conference, 16-18 october, Karlsruhe, Germany 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22262,
author = {Ricci, S. and Piacentini, A and Weaver, A.T. and Ata, R. and Goutal, N. },
title = {A variational data assimilation algorithm to estimate the salinity for the Berre lagoon with TELEMAC3D},
year = {2013},
organization = {XXth TELEMAC-MASCARET User conference, 16-18 october},
address = {Karlsruhe, Germany}}
Weaver, A.T. (2013) Covariance model and minimization for variational ocean data assimilation Recent advances in optimization, 24-26 July, Toulouse, France 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22445,
author = {Weaver, A.T. },
title = {Covariance model and minimization for variational ocean data assimilation},
year = {2013},
organization = {Recent advances in optimization, 24-26 July},
address = {Toulouse, France}}
Weaver, A.T. (2013) Assimilation diagnostics: examples from ORAS4, CLIVAR GSO/GODAE Ocean Reanalyses Intercomparison Workshop ECMXF, 1-3 July 2013, Reading, UK 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22446,
author = {Weaver, A.T. },
title = {Assimilation diagnostics: examples from ORAS4, CLIVAR GSO/GODAE Ocean Reanalyses Intercomparison},
year = {2013},
organization = {Workshop ECMXF, 1-3 July 2013},
address = {Reading, UK}}
Weaver, A.T., Corre, L. and Balmaseda, M.A. (2013) Evaluation of the ECMWF ensemble of ocean reanalyses using assimilation diagnostics Journées groupe mission Mercator Coriolis, 23-24april, 2013, Toulouse, France 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22449,
author = {Weaver, A.T. and Corre, L. and Balmaseda, M.A. },
title = {Evaluation of the ECMWF ensemble of ocean reanalyses using assimilation diagnostics},
year = {2013},
organization = {Journées groupe mission Mercator Coriolis, 23-24april, 2013},
address = {Toulouse, France}}
Weaver, A.T., Corre, L. and Balmaseda, M.A. (2013) Evaluation of the ECMWF ensemble of ocean reanalyses using assimilation diagnostics 6th WMO international symposium on data assimilation,7-11 october, Washington, USA 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22450,
author = {Weaver, A.T. and Corre, L. and Balmaseda, M.A. },
title = {Evaluation of the ECMWF ensemble of ocean reanalyses using assimilation diagnostics},
year = {2013},
organization = {6th WMO international symposium on data assimilation,7-11 october},
address = {Washington, USA}}
Ricci, S., Piacentini, A, Weaver, A.T., Ata, R. and Goutal, N. (2013) A variational data assimilation algorithm to estimate salinity in the Berre lagoon with TELEMAC3D, Sixth WMO Symposium on Data Assimilation. WMO2013, 07-11 October, Washington, USA 2013
[bibtex]
@CONFERENCE{PR-CMGC-13-22783,
author = {Ricci, S. and Piacentini, A and Weaver, A.T. and Ata, R. and Goutal, N. },
title = {A variational data assimilation algorithm to estimate salinity in the Berre lagoon with TELEMAC3D},
year = {2013},
booktitle = { Sixth WMO Symposium on Data Assimilation},
organization = {WMO2013, 07-11 October},
address = {Washington, USA}}
Gürol, S., Weaver, A.T., Gratton, S., Moore, A.M., Piacentini, A and Arango, H.G. (2012) B-preconditionned minimization algorithm for variational assimilation with the dual formulation 4eme colloque national sur l'assimilation de données, 17-19 december, Nice, France 2012
[bibtex]
@CONFERENCE{PR-CMGC-12-22015,
author = {Gürol, S. and Weaver, A.T. and Gratton, S. and Moore, A.M. and Piacentini, A and Arango, H.G. },
title = {B-preconditionned minimization algorithm for variational assimilation with the dual formulation},
year = {2012},
organization = {4eme colloque national sur l'assimilation de données, 17-19 december},
address = {Nice, France}}
Ricci, S., Piacentini, A, Riadh, A., Goutal, N., Weaver, A.T. and Ata, R. (2012) A variational data assimilation algorithm to better estimate the salinity for the Berre lagoon with TELEMAC sixth symposium on data assimilation, college park, 7-11 october, MD, USA 2012
[bibtex]
@CONFERENCE{PR-CMGC-12-22257,
author = {Ricci, S. and Piacentini, A and Riadh, A. and Goutal, N. and Weaver, A.T. and Ata, R. },
title = {A variational data assimilation algorithm to better estimate the salinity for the Berre lagoon with TELEMAC},
year = {2012},
organization = {sixth symposium on data assimilation, college park, 7-11 october},
address = {MD, USA}}
Weaver, A.T. (2012) Representing covariances in variationnal data assimilation using a diffusion operator Mathias 2012, 25-26 october, Paris, France 2012
[bibtex]
@CONFERENCE{PR-CMGC-12-22447,
author = {Weaver, A.T. },
title = {Representing covariances in variationnal data assimilation using a diffusion operator},
year = {2012},
organization = {Mathias 2012, 25-26 october},
address = {Paris, France}}
Weaver, A.T. and Piacentini, A (2012) Representing ensemble covariances with a diffusion operator International conference on ensemble methods in geophysical science, 12-16 november, Toulouse, France 2012
[bibtex]
@CONFERENCE{PR-CMGC-12-22457,
author = {Weaver, A.T. and Piacentini, A },
title = {Representing ensemble covariances with a diffusion operator},
year = {2012},
organization = {International conference on ensemble methods in geophysical science, 12-16 november},
address = {Toulouse, France}}
Mirouze, I. and Weaver, A.T. (2009) Representation of correlation functions using a one-dimensional implicit diffusion equation, with application to variational ocean data assimilation, 5th wmo symposium on data assimilation., Melbourne, Asutralia 2009
[bibtex]
@conference{PR-AE-09-20452,
author = {Mirouze, I. and Weaver, A.T. },
title = {Representation of correlation functions using a one-dimensional implicit diffusion equation, with application to variational ocean data assimilation},
year = {2009},
address = {Melbourne, Asutralia},
booktitle = {5th wmo symposium on data assimilation}}
Heimbach, P., Forget, G., Ponte, R.M., Wunsch, C., Balmaseda, M.A., Stammer, D., Awaji, T., Behringer, D., Carton, J., Ferry, N., Fischer, A., Fukumori, I., Giese, B., Haines, K., Harrison, E., Hernandez, F., Kamachi, M., Keppenne, C., Köhl, A., Lee, T., Menemenlis, D., Oke, P., Remy, E., Rienecker, M., Rosati, A., Smith, D. and Weaver, A.T. (2009) Observational requirements for global-scale ocean climate analysis:
lessons from ocean state estimation, Community white paper for oceanobs'09. 2009
[bibtex]
@conference{PR-CMGC-09-22054,
author = {Heimbach, P. and Forget, G. and Ponte, R.M. and Wunsch, C. and Balmaseda, M.A. and Stammer, D. and Awaji, T. and Behringer, D. and Carton, J. and Ferry, N. and Fischer, A. and Fukumori, I. and Giese, B. and Haines, K. and Harrison, E. and Hernandez, F. and Kamachi, M. and Keppenne, C. and K¨{o}hl, A. and Lee, T. and Menemenlis, D. and Oke, P. and Remy, E. and Rienecker, M. and Rosati, A. and Smith, D. and Weaver, A.T. },
title = {Observational requirements for global-scale ocean climate analysis:
lessons from ocean state estimation},
year = {2009},
booktitle = {Community white paper for oceanobs´09}}
Lee, T., Balmaseda, M.A., Remy, E., Haines, K., Harrison, E., Fischer, A., Awaji, T., Carton, J., Behringer, D., Ferry, N., Fukumori, I., Giese, B., Heimbach, P., Kamachi, M., Keppenne, C., Masina, S., Menemenlis, D., Ponte, R.M., Schroeter, J., Rienecker, M., Rosati, T., Smith, D., Wunsch, C., Köhl, A., Weaver, A.T. and Xue, Y. (2009) Ocean state estimation for climate research, Community white paper for oceanobs'09. 2009
[bibtex]
@conference{PR-CMGC-09-22088,
author = {Lee, T. and Balmaseda, M.A. and Remy, E. and Haines, K. and Harrison, E. and Fischer, A. and Awaji, T. and Carton, J. and Behringer, D. and Ferry, N. and Fukumori, I. and Giese, B. and Heimbach, P. and Kamachi, M. and Keppenne, C. and Masina, S. and Menemenlis, D. and Ponte, R.M. and Schroeter, J. and Rienecker, M. and Rosati, T. and Smith, D. and Wunsch, C. and K¨{o}hl, A. and Weaver, A.T. and Xue, Y. },
title = {Ocean state estimation for climate research},
year = {2009},
booktitle = {Community white paper for oceanobs´09}}
Mirouze, I. and Weaver, A.T. (2009) Representation of correlation functions using a one-dimensional implicit
diffusion equation, with application to variational ocean data assimilation, 5th wmo symposium on data assimilation., Melbourne, Asutralia 2009
[bibtex]
@conference{PR-CMGC-09-22161,
author = {Mirouze, I. and Weaver, A.T. },
title = {Representation of correlation functions using a one-dimensional implicit
diffusion equation, with application to variational ocean data assimilation},
year = {2009},
address = {Melbourne, Asutralia},
booktitle = {5th wmo symposium on data assimilation}}
Stammer, D., Köhl, A., Awaji, T., Balmaseda, M.A., Behringer, D., Carton, J., Ferry, N., Fischer, A., Fukumori, I., Giese, B., Haines, K., Harrison, E., Heimbach, P., Kamachi, M., Keppenne, C., Lee, T., Masina, S., Menemenlis, D., Ponte, R.M., Remy, E., Rienecker, M., Rosati, A., Schroeter, J., Smith, D., Weaver, A.T., Wunsch, C. and Xue, Y. (2009) Ocean variability evaluated from an ensemble of ocean syntheses, Community white paper for oceanobs'09. 2009
[bibtex]
@conference{PR-CMGC-09-22321,
author = {Stammer, D. and K¨{o}hl, A. and Awaji, T. and Balmaseda, M.A. and Behringer, D. and Carton, J. and Ferry, N. and Fischer, A. and Fukumori, I. and Giese, B. and Haines, K. and Harrison, E. and Heimbach, P. and Kamachi, M. and Keppenne, C. and Lee, T. and Masina, S. and Menemenlis, D. and Ponte, R.M. and Remy, E. and Rienecker, M. and Rosati, A. and Schroeter, J. and Smith, D. and Weaver, A.T. and Wunsch, C. and Xue, Y. },
title = {Ocean variability evaluated from an ensemble of ocean syntheses},
year = {2009},
booktitle = {Community white paper for oceanobs´09}}
Weaver, A.T. (2003) 3d-var and 4d-var approaches to ocean data assimilation, 13 - 15
november 2003
[bibtex]
@conference{PR-CMGC-03-22448,
author = {Weaver, A.T. },
title = {3d-var and 4d-var approaches to ocean data assimilation, 13 - 15
november},
year = {2003},
pages = {}}
Weaver, A.T. and Ricci, S. (2003) Constructing a background-error correlation model using generalized
diffusion operators, 8 -12 september 2003
[bibtex]
@conference{PR-CMGC-03-22458,
author = {Weaver, A.T. and Ricci, S. },
title = {Constructing a background-error correlation model using generalized
diffusion operators, 8 -12 september},
year = {2003},
pages = {327 - 339}}
De Mey, P., Awaji, T., Bell, M.J., Bennett, A.F., Brasseur, P., Evensen, G., Fukumori, I., Hurlburt, H., Stammer, D. and Weaver, A.T. (2002) Approaches to data assimilation within goda 2002
[bibtex]
@conference{PR-CMGC-02-21966,
author = {De Mey, P. and Awaji, T. and Bell, M.J. and Bennett, A.F. and Brasseur, P. and Evensen, G. and Fukumori, I. and Hurlburt, H. and Stammer, D. and Weaver, A.T. },
title = {Approaches to data assimilation within goda},
year = {2002},
pages = {}}
Weaver, A.T., Vialard, J., Anderson, D.L.T. and Delecluse, P. (2002) Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean 2002
[bibtex]
@conference{PR-CMGC-02-22463,
author = {Weaver, A.T. and Vialard, J. and Anderson, D.L.T. and Delecluse, P. },
title = {Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean},
year = {2002}}
Rogel, P., Weaver, A.T., Machu, E., Ricci, S. and Maisonnave, E. (2002) Variational ocean data assimilation system for improving seasonal
climate prediction 2002
[bibtex]
@conference{PR-CMGC-02-22747,
author = {Rogel, P. and Weaver, A.T. and Machu, E. and Ricci, S. and Maisonnave, E. },
title = {Variational ocean data assimilation system for improving seasonal
climate prediction},
year = {2002}}
Ricci, S., Weaver, A.T., Machu, E. and Rogel, P. (2002) Formulation de la matrice d'erreur de covariances de l'ebauche pour
un systeme d'assimilation oceanique: preservation des proprietes
de temperature-salinite 2002
[bibtex]
@conference{PR-CMGC-02-22784,
author = {Ricci, S. and Weaver, A.T. and Machu, E. and Rogel, P. },
title = {Formulation de la matrice d´erreur de covariances de l´ebauche pour
un systeme d´assimilation oceanique: preservation des proprietes
de temperature-salinite},
year = {2002}}
Weaver, A.T. and Vialard, J. (2001) Variational assimilation with the opa ogcm, Wcrp informal report no. 21/2001, clivar ocean observations panel, first session., Hobart, Australia 2001
[bibtex]
@conference{PR-CMGC-01-22459,
author = {Weaver, A.T. and Vialard, J. },
title = {Variational assimilation with the opa ogcm},
year = {2001},
pages = {34 - 36},
address = {Hobart, Australia},
booktitle = {Wcrp informal report no. 21/2001, clivar ocean observations panel,
first session}}
Machu, E., Rogel, P., Ricci, S., Weaver, A.T. and Maisonnave, E. (2001) Towards a variational assimilation system in the global ocean: 3d
and 4d twin experiments in the tropical pacific 2001
[bibtex]
@conference{PR-CMGC-01-22565,
author = {Machu, E. and Rogel, P. and Ricci, S. and Weaver, A.T. and Maisonnave, E. },
title = {Towards a variational assimilation system in the global ocean: 3d
and 4d twin experiments in the tropical pacific},
year = {2001}}
Machu, E., Rogel, P., Ricci, S., Weaver, A.T. and Maisonnave, E. (2001) Towards a variational assimilation system in the global ocean: 3d
and 4d twin experiments in the tropical pacific 2001
[bibtex]
@conference{PR-CMGC-01-22616,
author = {Machu, E. and Rogel, P. and Ricci, S. and Weaver, A.T. and Maisonnave, E. },
title = {Towards a variational assimilation system in the global ocean: 3d
and 4d twin experiments in the tropical pacific},
year = {2001}}
Piacentini, A., Weaver, A.T. and Blayo, E. (2001) Control of systematic model errors in variational data assimilation 2001
[bibtex]
@conference{PR-CMGC-01-22764,
author = {Piacentini, A. and Weaver, A.T. and Blayo, E. },
title = {Control of systematic model errors in variational data assimilation},
year = {2001}}
Vialard, J., Weaver, A.T. and Anderson, D.L.T. (2000) Assimilation de donnée contrainte par la dynamique océanique
dans le pacifique tropical, Atelier de modélisation de l'atmosphère ama2000. 2000
[bibtex]
@conference{PR-CMGC-00-22431,
author = {Vialard, J. and Weaver, A.T. and Anderson, D.L.T. },
title = {Assimilation de donn´{e}e contrainte par la dynamique oc´{e}anique
dans le pacifique tropical},
year = {2000},
pages = {23 - 25},
booktitle = {Atelier de mod´{e}lisation de l´atmosph`{e}re ama2000}}
Vidard, A., Le Dimet, F.-X., Piacentini, A. and Weaver, A.T. (2000) Contrôle du biais systématique du modèle en assimilation
de données variationnelle, Atelier de modélisation de l'atmosphère ama2000. 2000
[bibtex]
@conference{PR-CMGC-00-22437,
author = {Vidard, A. and Le Dimet, F.-X. and Piacentini, A. and Weaver, A.T. },
title = {Contr^{o}le du biais syst´{e}matique du mod`{e}le en assimilation
de donn´{e}es variationnelle},
year = {2000},
pages = {17 - 19},
booktitle = {Atelier de mod´{e}lisation de l´atmosph`{e}re ama2000}}
Weaver, A.T. and Vialard, J. (2000) Un 4d-var incrémental pour l'océan pacifique tropical: formulation
et validation de l'hypothèse linéaire tangente, Atelier de modélisation de l'atmosphère ama2000. 2000
[bibtex]
@conference{PR-CMGC-00-22460,
author = {Weaver, A.T. and Vialard, J. },
title = {Un 4d-var incr´{e}mental pour l´oc´{e}an pacifique tropical: formulation
et validation de l´hypoth`{e}se lin´{e}aire tangente},
year = {2000},
pages = {43 - 46},
booktitle = {Atelier de mod´{e}lisation de l´atmosph`{e}re ama2000}}
Weaver, A.T. and Vialard, J. (2000) Development of an ocean incremental 4d-var scheme for seasonal prediction., Proceedings of the third international symposium on assimilation of observations in meteorology and oceanography., Québec City, Canada, 7-11 June 1999 2000
[bibtex]
@conference{PR-CMGC-00-22461,
author = {Weaver, A.T. and Vialard, J. },
title = {Development of an ocean incremental 4d-var scheme for seasonal prediction.},
year = {2000},
pages = {191 - 194},
address = {{Q}u´{e}bec {C}ity, {C}anada, 7-11 {J}une 1999},
booktitle = {Proceedings of the third international symposium on assimilation
of observations in meteorology and oceanography}}
Rogel, P., Vidard, P., Weaver, A.T. and Piacentini, A. (2000) Vers un système d'assimilation variationnelle dans l'océan
global : expériences jumelles 3d et 4d dans le pacifique tropical 2000
[bibtex]
@conference{PR-CMGC-00-22756,
author = {Rogel, P. and Vidard, P. and Weaver, A.T. and Piacentini, A. },
title = {Vers un syst`{e}me d´assimilation variationnelle dans l´oc´{e}an
global : exp´{e}riences jumelles 3d et 4d dans le pacifique tropical},
year = {2000}}
@TECHREPORT
Weaver, A.T., Chrust, M., Ménétrier, B., Piacentini, A, Gürol, S., Tshimanga, J., Yang, Y. and Zuo, H. (2018) Using ensemble-estimated background error variances and correlation scales in the NEMOVAR system, Cerfacs TR-PA-18-15, Technical report
[bibtex] [pdf]
@TECHREPORT{TR-PA-18-15,
author = {Weaver, A.T. and Chrust, M. and Ménétrier, B. and Piacentini, A and Gürol, S. and Tshimanga, J. and Yang, Y. and Zuo, H. },
title = {Using ensemble-estimated background error variances and correlation scales in the NEMOVAR system},
year = {2018},
institution = {Cerfacs TR-PA-18-15},
type = {Technical report},
keywords = {data assimilation, variational assimilation, ensemble methods, covariance modelling},
pdf = {https://cerfacs.fr/wp-content/uploads/2018/01/TR-PA-18-15.pdf},
supplementaryMaterial = {https://cerfacs.fr/wp-content/uploads/2018/10/TR-PA-18-15.pdf}}
Weaver, A.T., Gürol, S., Tshimanga, J., Chrust, M. and Piacentini, A (2017) Time-parallel diffusion-based correlation operators, CERFACS TR-PA-17-119, Technical report
[bibtex] [pdf]
@TECHREPORT{TR-PA-17-119,
author = {Weaver, A.T. and Gürol, S. and Tshimanga, J. and Chrust, M. and Piacentini, A },
title = {Time-parallel diffusion-based correlation operators},
year = {2017},
institution = {CERFACS TR-PA-17-119},
type = {Technical report},
abstract = {Correlation operators based on the solution of an implicitly formulated diffusion equation can be implemented numerically using the Chebyshev iteration method.
The attractive properties of the algorithm for modelling correlation functions on high-performance computers have been discussed in a recent paper. The current paper describes a straightforward variant of that algorithm that allows the matrix-vector products involved in the sequential pseudo-time diffusion process to be performed in parallel.
Contrary to the original algorithm, which requires solving a sequence of linear systems involving a symmetric positive-definite (SPD) matrix, the ``time''-parallel algorithm requires solving a single linear system involving a nonsymmetric positive-definite (NSPD) matrix.
The key information required by the Chebyshev iteration for solving the NSPD problem is an estimate of the extreme eigenvalues of the NSPD matrix. For the problem under consideration, the extreme eigenvalues of the NSPD matrix are the same as those of the original SPD matrix, and can be pre-computed using a Lanczos algorithm.
The convergence properties of the algorithm are studied from a theoretical perspective and using numerical experiments with a diffusion-based covariance model employed with a variational data assimilation system for the global ocean. Results suggest that time-parallelization can reduce the run-time of an implicit diffusion-based correlation operator by greater than a factor of two.
It can be implemented practically using a hybrid parallelization approach that combines MPI tasks in the spatial domain with OpenMP threads spanning the pseudo-time dimension.
The sensitivity of the results to preconditioning, to the choice of first guess and to the stopping criterion is discussed.},
keywords = {correlation functions, covariance modelling, background error, Chebyshev iteration, time parallelization, nonsymmetric linear solver, variational assimilation, ocean data assimilation},
pdf = {https://cerfacs.fr/wp-content/uploads/2017/08/TR-PA-17-119.pdf},
supplementaryMaterial = {https://cerfacs.fr/wp-content/uploads/2018/10/TR-PA-17-119.pdf}}
Ricci, S., Piacentini, A, Weaver, A.T., Ata, R. and Goutal, N. (2013) A variational data assimilation algorithm to estimate salinity in the Berre Lagoon with Telemac3D, URA SUC 1875, CERFACS/CNRS, TR-CMGC-13-22263, technical report
[bibtex] [pdf]
@TECHREPORT{TR-CMGC-13-22263,
author = {Ricci, S. and Piacentini, A and Weaver, A.T. and Ata, R. and Goutal, N. },
title = {A variational data assimilation algorithm to estimate salinity in the Berre Lagoon with Telemac3D},
year = {2013},
institution = {URA SUC 1875, CERFACS/CNRS, TR-CMGC-13-22263},
type = {technical report},
address = {Toulouse, France},
pdf = {https://cerfacs.fr/wp-content/uploads/2017/03/GLOBC-TR_Ricci_T3DFGAT_TUC_2013.pdf}}
Gürol, S., Weaver, A.T., Moore, A.M., Piacentini, A, Arango, H.G. and Gratton, S. (2012) ${B}$-preconditioned minimization algorithms with the dual formulation, Cerfacs, Toulouse, France, Technical report
[bibtex]
[url]
@TECHREPORT{TR-PA-12-20311,
author = {Gürol, S. and Weaver, A.T. and Moore, A.M. and Piacentini, A and Arango, H.G. and Gratton, S. },
title = {${B}$-preconditioned minimization algorithms with the dual formulation},
year = {2012},
institution = {{Cerfacs}, Toulouse, France},
type = {Technical report},
url = {https://cerfacs.fr/algor/reports/2012/TR_PA_12_118.pdf}}
Gürol, S., Weaver, A.T., Moore, A.M., Piacentini, A, Arango, H.G. and Gratton, S. (2012) B-preconditioned minimization algorithms for variationnal data assimilation using the dual-space formulation, URA SUC 1875, CERFACS-CNRS, TR-CMGC-12-22017, Technical report
[bibtex]
@TECHREPORT{TR-CMGC-12-22017,
author = {Gürol, S. and Weaver, A.T. and Moore, A.M. and Piacentini, A and Arango, H.G. and Gratton, S. },
title = {B-preconditioned minimization algorithms for variationnal data assimilation using the dual-space formulation},
year = {2012},
institution = {URA SUC 1875, CERFACS-CNRS, TR-CMGC-12-22017},
address = {Toulouse, France},
type = {Technical report}}
Mogensen, K., Balmaseda, M.A. and Weaver, A.T. (2012) The NEMOVAR ocean data assimilation system as implemented in the ECMWF ocean analysis for system 4, ECMWF Tech. Memo., 668, 60 pp, technical report
[bibtex]
@TECHREPORT{TR-CMGC-12-22162,
author = {Mogensen, K. and Balmaseda, M.A. and Weaver, A.T. },
title = {The NEMOVAR ocean data assimilation system as implemented in the ECMWF ocean analysis for system 4},
year = {2012},
institution = {ECMWF Tech. Memo., 668, 60 pp},
type = {technical report}}
Balmaseda, M.A., Mogensen, K., Molteni, F. and Weaver, A.T. (2010) The NEMOVAR-COMBINE ocean Reanalysis, URA SUC 1875, CERFACS-CNRS, TR-CMGC-10-21817, Technical report
[bibtex]
@TECHREPORT{TR-CMGC-10-21817,
author = {Balmaseda, M.A. and Mogensen, K. and Molteni, F. and Weaver, A.T. },
title = {The NEMOVAR-COMBINE ocean Reanalysis},
year = {2010},
institution = {URA SUC 1875, CERFACS-CNRS, TR-CMGC-10-21817},
address = {Toulouse, France},
type = {Technical report}}
Bouriquet, B., Ricci, S., Argaud, J.-Ph., Piacentini, A, Massart, S., Weaver, A.T. and Thual, O. (2009) Applications du CERFACS en assimilation de données, URA SUC 1875, CERFACS-CNRS, TR-CMGC-09-22652, Technical report
[bibtex]
[url]
@TECHREPORT{TR-CMGC-09-22652,
author = {Bouriquet, B. and Ricci, S. and Argaud, J.-Ph. and Piacentini, A and Massart, S. and Weaver, A.T. and Thual, O. },
title = {Applications du CERFACS en assimilation de données},
year = {2009},
institution = {URA SUC 1875, CERFACS-CNRS, TR-CMGC-09-22652},
address = {Toulouse, France},
type = {Technical report},
url = {https://cerfacs.fr/globc/publication/technicalreport/2009/actes49.pdf}}
Daget, N., Weaver, A.T. and Balmaseda, M.A. (2008) An ensemble three-dimensional variational data assimilation system
for the global ocean: sensitivity to the observation- and background-error
variance formulation, Cerfacs, cerfacs technical report
[bibtex]
@techreport{TR-CMGC-08-21958,
author = {Daget, N. and Weaver, A.T. and Balmaseda, M.A. },
title = {An ensemble three-dimensional variational data assimilation system
for the global ocean: sensitivity to the observation- and background-error
variance formulation},
year = {2008},
institution = {Cerfacs},
type = {cerfacs technical report}}
Ferry, N., Guérémy, J.-F., Troccoli, A., Weaver, A.T. and Gualdi, S. (2007) Within the gmes and towards the marine core service at mercator-ocean, mercator-ocean quarterly newsletter
[bibtex]
@techreport{TR-CMGC-07-22009,
author = {Ferry, N. and Gu´{e}r´{e}my, J.-F. and Troccoli, A. and Weaver, A.T. and Gualdi, S. },
title = {Within the gmes and towards the marine core service at mercator-ocean},
year = {2007},
type = {mercator-ocean quarterly newsletter}}
Davey, M., Huddleston, M., Ingleby, B., Haines, K., Weaver, A.T., Vialard, J., Anderson, D.L.T., Troccoli, A., Vidard, A., Burgers, G., Leeuwenburgh, O., Bellucci, A., Masina, S., Bertino, L. and Korn, P. (2006) Multi-model multi-method multi-decadal ocean analyses from the enact
project, clivar exchanges 38
[bibtex]
@techreport{TR-CMGC-06-21962,
author = {Davey, M. and Huddleston, M. and Ingleby, B. and Haines, K. and Weaver, A.T. and Vialard, J. and Anderson, D.L.T. and Troccoli, A. and Vidard, A. and Burgers, G. and Leeuwenburgh, O. and Bellucci, A. and Masina, S. and Bertino, L. and Korn, P. },
title = {Multi-model multi-method multi-decadal ocean analyses from the enact
project},
year = {2006},
type = {clivar exchanges 38}}
Weaver, A.T., Vialard, J., Anderson, D.L.T. and Delecluse, P. (2002) Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean, ECMWF, tech. memo.
[bibtex]
@techreport{TR-CMGC-02-22465,
author = {Weaver, A.T. and Vialard, J. and Anderson, D.L.T. and Delecluse, P. },
title = {Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean},
year = {2002},
institution = {ECMWF},
type = {tech. memo.}}
Weaver, A.T., Vialard, J., Anderson, D.L.T. and Delecluse, P. (2002) Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean, ECMWF, technical memorandum
[bibtex]
@techreport{TR-CMGC-02-22466,
author = {Weaver, A.T. and Vialard, J. and Anderson, D.L.T. and Delecluse, P. },
title = {Three- and four-dimensional variational assimilation with an ocean
general circulation model of the tropical pacific ocean},
year = {2002},
institution = {ECMWF},
type = {technical memorandum}}
Moore, A.M., Vialard, J., Weaver, A.T., Anderson, D.L.T., Kleeman, R. and Johnson, J.R. (2001) The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled ocean-atmosphere modes, ECMWF, technical memorandum
[bibtex]
@techreport{TR-CMGC-01-22172,
author = {Moore, A.M. and Vialard, J. and Weaver, A.T. and Anderson, D.L.T. and Kleeman, R. and Johnson, J.R. },
title = {The role of air-sea interaction in controlling the optimal perturbations
of low-frequency tropical coupled ocean-atmosphere modes},
year = {2001},
institution = {ECMWF},
type = {technical memorandum}}
Weaver, A.T. and Courtier, P. (2000) Correlation modelling on the sphere using a generalized diffusion
equation, ECMWF, tech. memo.
[bibtex]
@techreport{TR-CMGC-00-22452,
author = {Weaver, A.T. and Courtier, P. },
title = {Correlation modelling on the sphere using a generalized diffusion
equation},
year = {2000},
institution = {ECMWF},
type = {tech. memo.}}
