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Papers by Philip Muscarella

Research paper thumbnail of On the direct assimilation of along-track sea surface height observations into a free-surface ocean model using a weak constraints four dimensional variational (4dvar) method

Quarterly Journal of the Royal Meteorological Society, 2015

Research paper thumbnail of Impact of Assimilating Surface Velocity Observations on the Model Sea Surface Height using the NCOM-4DVAR

Monthly Weather Review, 2015

Research paper thumbnail of Comparison of HF Radar and ADCP Surface Currents at the Delaware Bay Mouth

2008 IEEE/OES 9th Working Conference on Current Measurement Technology, 2008

Coastal surface currents measured remotely by high frequency (HF) radar are compared with those f... more Coastal surface currents measured remotely by high frequency (HF) radar are compared with those from in situ acoustic Doppler current profilers (ADCP) deployed in both Eulerian and Lagrangian configurations. Two 25 MHz CODAR SeaSondesreg, located at Cape May, NJ and Cape Henlopen, DE, continuously measure surface currents at the Delaware Bay mouth. The radars measure surface current hourly with a

Research paper thumbnail of Assimilation of HF Radar Observations in the Chesapeake–Delaware Bay Region Using the Navy Coastal Ocean Model (NCOM) and the Four-Dimensional Variational (4DVAR) Method

Coastal Ocean Observing Systems, 2015

Research paper thumbnail of AGU Oceans 2012 Poster : A Multi-Scale 3D Variational Data Assimilation Scheme (MS-3DVAR) in the Kurshio Extension

A new MS-3DVAR method has been developed at the Naval Research Lab (NRL) for use with the Naval C... more A new MS-3DVAR method has been developed at the Naval Research Lab (NRL) for use with the Naval Coastal Ocean Model (NCOM). The advantage of a multi-scale approach to data assimilation is the ability to resolve the multiple spatial scales present in regional ocean models. This method relies on the specification of large and small the horizontal length scales and their associated background error covariances. Using empirical orthogonal functions (EOF) the variances associated with pre-specified length scales can be determined. An additional benefit of the MS-3DVAR technique is the ability to assimilate coarse and dense collections of observations. The benefits are examined in a region of the Kuroshio where meso-scale eddies are prevalent and the dense observations are needed to constrain these features.

Research paper thumbnail of Do assimilated drifter velocities improve Lagrangian predictability in an operational ocean model?

Monthly Weather Review, 2015

Research paper thumbnail of ASSIMILATING DRIFTER VELOCITIES TO IMPROVE LAGRANGIAN PREDICTABILITY

Velocity observations from Lagrangian drifters deployed in the Gulf of Mexico during the summer 2... more Velocity observations from Lagrangian drifters deployed in the Gulf of Mexico during the summer 2012 Grand Lagrangian Deployment (GLAD) experiment are assimilated into the Naval Coastal Ocean Model (NCOM) 4D variational (4DVAR) analysis system to examine their impact on Lagrangian predictability. NCOM-4DVAR is a weak-constraint assimilation system using the in-direct representer method. Eulerian velocities, derived from the drifters, as well as satellite and in-situ observations are assimilated. Lagrangian predictability is accessed via the separation distance and angular differences between simulated drifter trajectories. Results show that the inclusion of the drifter velocities to the assimilated observations reduces the separation distance by approximately 10km per day when compared against experiments which assimilate only temperature and salinity observations. Additionally, the assimilation of these observations via the NCOM-4DVAR improves the characterization of the general ci...

Research paper thumbnail of The impact of initial spread calibration on the RELO ensemble and its application to Lagrangian dynamics

Nonlinear Processes in Geophysics, 2013

Research paper thumbnail of Impact of Assimilating Ocean Velocity Observations Inferred from Lagrangian Drifter Data Using the NCOM-4DVAR*

Monthly Weather Review, 2014

Research paper thumbnail of How useful are progressive vector diagrams for studying coastal ocean transport?

Limnology and Oceanography: Methods, 2010

Research paper thumbnail of Surface currents and winds at the Delaware Bay mouth

Continental Shelf Research, 2011

Research paper thumbnail of An examination of a multi-scale three-dimensional variational data assimilation scheme in the Kuroshio Extension using the naval coastal ocean model

Continental Shelf Research, 2014

Research paper thumbnail of Nanostructured Bi2Se3 Films and Their Thermoelectric Transport Properties

Angewandte Chemie International Edition, 2006

Research paper thumbnail of The performance of the US Navy's RELO ensemble, NCOM, HYCOM during the period of GLAD at-sea experiment in the Gulf of Mexico

Deep Sea Research Part II: Topical Studies in Oceanography, 2013

ABSTRACT A suite of real-time ocean model forecasts was carried out successfully at NRL to provid... more ABSTRACT A suite of real-time ocean model forecasts was carried out successfully at NRL to provide modeling support and guidance to the CARTHE GLAD at-sea experiment during summer 2012. The forecast systems include two RELO ensembles and three single models using NCOM and HYCOM with different resolutions. All of these forecast outputs are archived and made available on web servers for the CARTHE scientists. The detailed descriptions of these forecast systems and the products presented in this paper provide a much-needed background to the scientists in CARTHE and others who will use our forecasts and GLAD drifter observations to do further research after the future public release of the CARTHE GLAD data. A calibrated ensemble system with enhanced spread and reliability is proposed in this project. It is found that this calibrated ensemble outperforms the un-calibrated ensemble in terms of quantitative forecasting accuracy, skill and reliability for all the variables and observation spaces we have evaluated. The metrics used include RMS error, anomaly correlation, spread-reliability and Talagrand rank histogram. Both ensembles are compared with three single-model forecasts with NCOM and HYCOM with different resolutions. The advantages of ensembles are demonstrated. RELO ensembles have been applied to Lagrangian trajectory prediction, and it is demonstrated that either ensemble can provide valuable uncertainty information in addition to predicting the particle trajectory with highest probability in comparison with a single ocean model forecast. The calibrated ensemble with more reliability is able to capture some trajectories in different, even opposite directions which are missed by the un-calibrated ensemble. When the ensembles are applied to computing the LCS (Lagrangian Coherent Structure), the uncertainties of the LCSs, which cannot be estimated from a single model forecast, are identified. Another finding is that the LCS depends on the model resolution. The model with highest resolution produces the finest small-scale LCS structures, while the model with lowest resolution generates only large scale LCSs. The work on using ocean ensembles in Lagrangian ocean dynamics presented in this paper represents our initial attempt in this field. It is expected that this work will lead to more extensive new research in this area in the near future.

Research paper thumbnail of On the direct assimilation of along-track sea surface height observations into a free-surface ocean model using a weak constraints four dimensional variational (4dvar) method

Quarterly Journal of the Royal Meteorological Society, 2015

Research paper thumbnail of Impact of Assimilating Surface Velocity Observations on the Model Sea Surface Height using the NCOM-4DVAR

Monthly Weather Review, 2015

Research paper thumbnail of Comparison of HF Radar and ADCP Surface Currents at the Delaware Bay Mouth

2008 IEEE/OES 9th Working Conference on Current Measurement Technology, 2008

Coastal surface currents measured remotely by high frequency (HF) radar are compared with those f... more Coastal surface currents measured remotely by high frequency (HF) radar are compared with those from in situ acoustic Doppler current profilers (ADCP) deployed in both Eulerian and Lagrangian configurations. Two 25 MHz CODAR SeaSondesreg, located at Cape May, NJ and Cape Henlopen, DE, continuously measure surface currents at the Delaware Bay mouth. The radars measure surface current hourly with a

Research paper thumbnail of Assimilation of HF Radar Observations in the Chesapeake–Delaware Bay Region Using the Navy Coastal Ocean Model (NCOM) and the Four-Dimensional Variational (4DVAR) Method

Coastal Ocean Observing Systems, 2015

Research paper thumbnail of AGU Oceans 2012 Poster : A Multi-Scale 3D Variational Data Assimilation Scheme (MS-3DVAR) in the Kurshio Extension

A new MS-3DVAR method has been developed at the Naval Research Lab (NRL) for use with the Naval C... more A new MS-3DVAR method has been developed at the Naval Research Lab (NRL) for use with the Naval Coastal Ocean Model (NCOM). The advantage of a multi-scale approach to data assimilation is the ability to resolve the multiple spatial scales present in regional ocean models. This method relies on the specification of large and small the horizontal length scales and their associated background error covariances. Using empirical orthogonal functions (EOF) the variances associated with pre-specified length scales can be determined. An additional benefit of the MS-3DVAR technique is the ability to assimilate coarse and dense collections of observations. The benefits are examined in a region of the Kuroshio where meso-scale eddies are prevalent and the dense observations are needed to constrain these features.

Research paper thumbnail of Do assimilated drifter velocities improve Lagrangian predictability in an operational ocean model?

Monthly Weather Review, 2015

Research paper thumbnail of ASSIMILATING DRIFTER VELOCITIES TO IMPROVE LAGRANGIAN PREDICTABILITY

Velocity observations from Lagrangian drifters deployed in the Gulf of Mexico during the summer 2... more Velocity observations from Lagrangian drifters deployed in the Gulf of Mexico during the summer 2012 Grand Lagrangian Deployment (GLAD) experiment are assimilated into the Naval Coastal Ocean Model (NCOM) 4D variational (4DVAR) analysis system to examine their impact on Lagrangian predictability. NCOM-4DVAR is a weak-constraint assimilation system using the in-direct representer method. Eulerian velocities, derived from the drifters, as well as satellite and in-situ observations are assimilated. Lagrangian predictability is accessed via the separation distance and angular differences between simulated drifter trajectories. Results show that the inclusion of the drifter velocities to the assimilated observations reduces the separation distance by approximately 10km per day when compared against experiments which assimilate only temperature and salinity observations. Additionally, the assimilation of these observations via the NCOM-4DVAR improves the characterization of the general ci...

Research paper thumbnail of The impact of initial spread calibration on the RELO ensemble and its application to Lagrangian dynamics

Nonlinear Processes in Geophysics, 2013

Research paper thumbnail of Impact of Assimilating Ocean Velocity Observations Inferred from Lagrangian Drifter Data Using the NCOM-4DVAR*

Monthly Weather Review, 2014

Research paper thumbnail of How useful are progressive vector diagrams for studying coastal ocean transport?

Limnology and Oceanography: Methods, 2010

Research paper thumbnail of Surface currents and winds at the Delaware Bay mouth

Continental Shelf Research, 2011

Research paper thumbnail of An examination of a multi-scale three-dimensional variational data assimilation scheme in the Kuroshio Extension using the naval coastal ocean model

Continental Shelf Research, 2014

Research paper thumbnail of Nanostructured Bi2Se3 Films and Their Thermoelectric Transport Properties

Angewandte Chemie International Edition, 2006

Research paper thumbnail of The performance of the US Navy's RELO ensemble, NCOM, HYCOM during the period of GLAD at-sea experiment in the Gulf of Mexico

Deep Sea Research Part II: Topical Studies in Oceanography, 2013

ABSTRACT A suite of real-time ocean model forecasts was carried out successfully at NRL to provid... more ABSTRACT A suite of real-time ocean model forecasts was carried out successfully at NRL to provide modeling support and guidance to the CARTHE GLAD at-sea experiment during summer 2012. The forecast systems include two RELO ensembles and three single models using NCOM and HYCOM with different resolutions. All of these forecast outputs are archived and made available on web servers for the CARTHE scientists. The detailed descriptions of these forecast systems and the products presented in this paper provide a much-needed background to the scientists in CARTHE and others who will use our forecasts and GLAD drifter observations to do further research after the future public release of the CARTHE GLAD data. A calibrated ensemble system with enhanced spread and reliability is proposed in this project. It is found that this calibrated ensemble outperforms the un-calibrated ensemble in terms of quantitative forecasting accuracy, skill and reliability for all the variables and observation spaces we have evaluated. The metrics used include RMS error, anomaly correlation, spread-reliability and Talagrand rank histogram. Both ensembles are compared with three single-model forecasts with NCOM and HYCOM with different resolutions. The advantages of ensembles are demonstrated. RELO ensembles have been applied to Lagrangian trajectory prediction, and it is demonstrated that either ensemble can provide valuable uncertainty information in addition to predicting the particle trajectory with highest probability in comparison with a single ocean model forecast. The calibrated ensemble with more reliability is able to capture some trajectories in different, even opposite directions which are missed by the un-calibrated ensemble. When the ensembles are applied to computing the LCS (Lagrangian Coherent Structure), the uncertainties of the LCSs, which cannot be estimated from a single model forecast, are identified. Another finding is that the LCS depends on the model resolution. The model with highest resolution produces the finest small-scale LCS structures, while the model with lowest resolution generates only large scale LCSs. The work on using ocean ensembles in Lagrangian ocean dynamics presented in this paper represents our initial attempt in this field. It is expected that this work will lead to more extensive new research in this area in the near future.