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Physical Sciences and Mathematics Commons

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University of South Florida

Environmental Sciences

Selected Works

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Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Tracking The Deepwater Horizon Oil Spill: A Modeling Perspective, Yonggang Liu, Robert H. Weisberg, Chuanmin Hu, Lianyuan Zheng Feb 2011

Tracking The Deepwater Horizon Oil Spill: A Modeling Perspective, Yonggang Liu, Robert H. Weisberg, Chuanmin Hu, Lianyuan Zheng

Yonggang Liu

The Deepwater Horizon oil spill was caused by a drilling rig explosion on 20 April 2010 that killed 11 people. It was the largest oil spill in U.S. history and presented an unprecedented threat to Gulf of Mexico marine resources. Although oil gushing to the surface diminished after the well was capped, on 15 July 2010, much remains to be known about the oil and the dispersants beneath the surface, including their trajectories and effects on marine life. A system for tracking the oil, both at the surface and at depth, was needed for mitigation efforts and ship survey guidance. …


Evaluation Of Trajectory Modeling In Different Dynamic Regions Using Normalized Cumulative Lagrangian Separation, Yonggang Liu, Robert H. Weisberg Jan 2011

Evaluation Of Trajectory Modeling In Different Dynamic Regions Using Normalized Cumulative Lagrangian Separation, Yonggang Liu, Robert H. Weisberg

Yonggang Liu

The Lagrangian separation distance between the endpoints of simulated and observed drifter trajectories is often used to assess the performance of numerical particle trajectory models. However, the separation distance fails to indicate relative model performance in weak and strong current regions, such as a continental shelf and its adjacent deep ocean. A new skill score is proposed based on the cumulative Lagrangian separation distances normalized by the associated cumulative trajectory lengths. This skill score is used to evaluate surface trajectories implied by Global HYCOM hindcast surface currents as gauged against actual satellite-tracked drifter trajectories in the eastern Gulf of Mexico …


Evolution Of The Loop Current System During The Deepwater Horizon Oil Spill Event As Observed With Drifters And Satellites, Yonggang Liu, Robert H. Weisberg, Charles Kovach, Rolf Riethmüller Jan 2011

Evolution Of The Loop Current System During The Deepwater Horizon Oil Spill Event As Observed With Drifters And Satellites, Yonggang Liu, Robert H. Weisberg, Charles Kovach, Rolf Riethmüller

Yonggang Liu

The ocean circulation patterns of the Gulf of Mexico (GOM) Loop Current (LC) system and their effects on the advection of the oil discharged during the Deepwater Horizon incident are described using in situ surface drifter trajectories and satellite observations from May to August 2010. These observations include altimetry-derived surface geostrophic velocities, sea surface temperature, ocean color, and surface oil locations. The elongated, northwestward penetrating LC retreated back from its northernmost position in late April 2010 and stayed farther away from the surface oil in the north during May 2010. Although the main body of the surface oil slick remained …


Hf Radar Performance In A Low-Energy Environment: Codar Seasonde Experience On The West Florida Shelf, Yonggang Liu, Robert H. Weisberg, Clifford R. Merz, Sage Litchtenwalner, Gary J. Kirkpatrick Oct 2010

Hf Radar Performance In A Low-Energy Environment: Codar Seasonde Experience On The West Florida Shelf, Yonggang Liu, Robert H. Weisberg, Clifford R. Merz, Sage Litchtenwalner, Gary J. Kirkpatrick

Yonggang Liu

Three long-range (5 MHz) Coastal Ocean Dynamics Application Radar (CODAR) SeaSonde HF radars overlooking an array of as many as eight moored acoustic Doppler current profilers (ADCPs) have operated on the West Florida Shelf since September 2003 for the purpose of observing the coastal ocean currents. HF radar performance on this low-energy (currents and waves) continental shelf is evaluated with respect to data returns, the rms differences between the HF radar and the ADCP radial currents, bearing offsets, and radial velocity uncertainties. Possible environmental factors affecting the HF radar performance are discussed, with the findings that both the low-energy sea …