TITLE

Ensemble-Based Simultaneous State and Parameter Estimation in a Two-Dimensional Sea-Breeze Model

AUTHOR(S)
Aksoy, Altuğ; Zhang, Fuqing; Nielsen-Gammon, John W.
PUB. DATE
October 2006
SOURCE
Monthly Weather Review;Oct2006, Vol. 134 Issue 10, p2951
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The performance of the ensemble Kalman filter (EnKF) in forced, dissipative flow under imperfect-model conditions is investigated through simultaneous state and parameter estimation where the source of model error is the uncertainty in the model parameters. A two-dimensional, nonlinear, hydrostatic, nonrotating, and incompressible sea-breeze model is used for this purpose with buoyancy and vorticity as the prognostic variables and a square root filter with covariance localization is employed. To control filter divergence caused by the narrowing of parameter variance, a “conditional covariance inflation” method is devised. Up to six model parameters are subjected to estimation attempts in various experiments. While the estimation of single imperfect parameters results in error of model variables that is indistinguishable from the respective perfect-parameter cases, increasing the number of estimated parameters to six inevitably leads to a decline in the level of improvement achieved by parameter estimation. However, the overall EnKF performance in terms of the error statistics is still superior to the situation where there is parameter error but no parameter estimation is performed. In fact, compared with that situation, the simultaneous estimation of six parameters reduces the average error in buoyancy and vorticity by 40% and 46%, respectively. Several aspects of the filter configuration (e.g., observation location, ensemble size, radius of influence, and parameter variance limit) are found to considerably influence the identifiability of the parameters. The parameter-dependent response to such factors implies strong nonlinearity between the parameters and the state of the model and suggests that a straightforward spatial covariance localization does not necessarily produce optimality.
ACCESSION #
22809097

 

Related Articles

  • Decadal Response of Global Circulation to Southern Ocean Zonal Wind Stress Perturbation. Klinger, Barry A.; Cruz, Carlos // Journal of Physical Oceanography;Aug2009, Vol. 39 Issue 8, p1888 

    A substantial component of North Atlantic Deep Water formation may be driven by westerly wind stress over the Southern Ocean. Variability of this wind stress on decadal time scales may lead to circulation variability far from the forcing region. The Hybrid Coordinate Ocean Model (HYCOM), a...

  • El Niño in a Coupled Climate Model: Sensitivity to Changes in Mean State Induced by Heat Flux and Wind Stress Corrections. Spencer, Hilary; Sutton, Rowan; Slingo, Julia M. // Journal of Climate;May2007, Vol. 20 Issue 10, p2273 

    Here the factors affecting the mean state and El Niño variability in the Third Hadley Centre Coupled Ocean–Atmosphere General Circulation Model (HadCM3) are examined with and without heat flux or wind stress corrections. There is currently little confidence in the prediction of El...

  • NATURAL RESOURCES: A $1 million study predicts the future of Colorado's water. Best, Allen // ColoradoBiz;Apr2010, Vol. 37 Issue 4, p13 

    The article presents the findings from the Colorado River Water Availability Study. It predicts that the state's Western Slope will become hotter and crops like corn and alfalfa will require more water. The author explains that the study analyzes information found in global circulation models as...

  • Global Circulation of the Atmosphere (2004). Schneider, Tapio; Sobel, Adam // Bulletin of the American Meteorological Society;Jun2006, Vol. 87 Issue 6, p807 

    The article discusses the developments during the three-day conference on the global circulation of the atmosphere at the California Institute of Technology on November 4-6, 2004 in Pasadena, California. Isaac Held opened the conference with a talk on the important issues on global circulation...

  • Tropospheric Response to Stratospheric Sudden Warmings in a Simple Global Circulation Model. Taguchi, Masakazu // Journal of Climate;Sep2003, Vol. 16 Issue 18, p3039 

    A composite analysis is made of 132 stratospheric sudden warming (SSW) events obtained in a 10 000-day integration with a simple global circulation model under a perpetual-winter condition. The analysis confirms general features of the SSWs, such as enhanced upward propagation of planetary wave...

  • Objective Debiasing for Improved Forecasting of Tropical Cyclone Intensity with a Global Circulation Model. Goswami, P.; Mallick, S.; Gouda, K. C. // Monthly Weather Review;Aug2011, Vol. 139 Issue 8, p2471 

    The damage potential of a tropical cyclone is proportional to a power (generally greater than one) of intensity, which demands high accuracy in forecasting intensity for managing this natural disaster. However, the current skill in forecasting cyclone intensity is rather limited, especially over...

  • A simple hydrologic framework for simulating wetlands in climate and earth system models. Fan, Ying; Miguez-Macho, Gonzalo // Climate Dynamics;Jul2011, Vol. 37 Issue 1/2, p253 

    Wetlands are ecosystems of important functions in the earth's climate system. Through relatively high evapotranspiration, they affect surface water and energy exchange with the atmosphere directly influencing the physical climate. Through CH, CO and NO fluxes, they regulate the biogeochemical...

  • Indirect downscaling of hourly precipitation based on atmospheric circulation and temperature. Beck, F.; Bárdossy, A. // Hydrology & Earth System Sciences;Dec2013, Vol. 17 Issue 12, p4851 

    The main source of information on future climate conditions are global circulation models (GCMs). While the various GCMs agree on an increase of surface temperature, the predictions for precipitation exhibit high spread among the models, especially in shorter-than-daily temporal resolution. This...

  • Evaluation of the twenty-first century RCM simulations driven by multiple GCMs over the Eastern Mediterranean-Black Sea region. Önol, Barış; Bozkurt, Deniz; Turuncoglu, Ufuk; Sen, Omer; Dalfes, H. // Climate Dynamics;Apr2014, Vol. 42 Issue 7/8, p1949 

    In this study, human-induced climate change over the Eastern Mediterranean-Black Sea region has been analyzed for the twenty-first century by performing regional climate model simulations forced with large-scale fields from three different global circulation models (GCMs). Climate projections...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics