Publications

Dual number-based variational data assimilation: Constructing exact tangent linear and adjoint code from nonlinear model evaluations

Dual numbers allow for automatic, exact evaluation of the numerical derivative of high-dimensional functions at an arbitrary point with …

A Simple Finite Difference‐Based Approximation for Biogeochemical Tangent Linear and Adjoint Models

We present a technique that accurately approximates tangent linear and adjoint models for data assimilation applications using only …

Improving Variational Data Assimilation through Background and Observation Error Adjustments

A procedure to objectively adjust the error covariance matrices of a variational data assimilation system is presented. It is based on …

Modeling of nitrogen and phosphorus profiles in sediment of Osaka Bay , Japan with parameter optimization using the polynomial chaos expansion

Coastal sediments adjacent to urban centers often receive high loads of organic matter (OM) due to large nutrient inputs from land that …

Simple parameter estimation for complex models — Testing evolutionary techniques on 3-dimensional biogeochemical ocean models

Parameter estimation is an important part of numerical modeling and often required when a coupled physical–biogeochemical ocean model …

Data assimilation of physical and chlorophyll a observations in the California Current System using two biogeochemical models

Biogeochemical numerical models coupled to physical ocean circulation models are commonly combined with data assimilation in order to …

Model investigations of the North Atlantic spring bloom initiation

The spring bloom – a massive growth of phytoplankton that occurs annually during the spring season in mid and high latitudes …

Periodic time-dependent parameters improving forecasting abilities of biological ocean models

Using two emulator-based procedures, we estimate time-dependent values for two key plankton parameters in a three-dimensional …

Sensitivity and uncertainty analysis of model hypoxia estimates for the Texas-Louisiana shelf

Numerical ocean models are becoming increasingly important tools for marine research and for management of marine resources. It is …

Simulating sediment-water exchange of nutrients and oxygen: A comparative assessment of models against mesocosm observations

How to represent nutrient fluxes resulting from organic matter remineralization in sediments should be an important consideration when …

Particle filter-based data assimilation for a three-dimensional biological ocean model and satellite observations

We assimilate satellite observations of surface chlorophyll into a three-dimensional biological ocean model in order to improve its …

Estimating time-dependent parameters for a biological ocean model using an emulator approach

We use a statistical emulator technique, the polynomial chaos expansion, to estimate time-dependent values for two parameters of a …

Data assimilation with a local Ensemble Kalman Filter applied to a three-dimensional biological model of the Middle Atlantic Bight

A multivariate sequential data assimilation approach, the Localized Ensemble Kalman Filter (LEnKF), was used to assimilate daily …

A geologically constrained Monte Carlo approach to modeling exposure ages from profiles of cosmogenic nuclides: An example from Lees Ferry, Arizona

We present a user‐friendly and versatile Monte Carlo simulator for modeling profiles of in situ terrestrial cosmogenic nuclides (TCNs). …

Introduction and Assessment of Measures for Quantitative Model-Data Comparison Using Satellite Images

Satellite observations of the oceans have great potential to improve the quality and predictive power of numerical ocean models and are …

Sequential data assimilation applied to a physical-biological model for the Bermuda Atlantic time series station

In this study, we investigate sequential data assimilation approaches for state estimation and prediction in a coupled …