Research at the Earth Scan Laboratory

ESL professors, staff, and students have partnered with researchers across scientific disciplines and the world in order to gain a broader view of oceanic, atmospheric and coastal processes around the world. Selected past and current research endeavors are described below.

Publications from the Earth Scan Lab

Animation of sea surface temperatures throughout 2011
2005 Storm Induced Ocean Cooling


The Earth Scan Laboratory participates in the Gulf of Mexico Coastal Ocean Observing System (GCOOS) by providing 1 km sea surface temperature (SST) quick-look images and HDFs via our image archive. GCOOS is the Gulf of Mexico component of NOAA's Integrated Ocean Observing System (IOOS).
The ESL captures data from all of NOAA's active POES series satellites equipped with the Advanced Very High Resolution Radiometer (AVHRR). SST is calculated for every satellite pass captured using the standard MCSST algorithm. Individual as well as nightly, 3-night, 7-night, 15-night, and 30-night composite images and HDFs are available daily. These images can also be viewed using the Animation Generator page. 

Loop Current and Eddy Circulation Studies

The Gulf of Mexico Loop Current is one of the most dynamic ocean currents in the world. Walker and staff have developed specialized image processing techniques that provide better and more frequent SST retrievals in the Gulf to monitor these currents. Gulf currents are known to impact hurricanes.
The Loop Current and the warm-core eddies that separate from it are large reservoirs of heat that have the capability to intensify hurricanes and tropical storms crossing the Gulf. Conversely, Walker’s research has shown that cold-core eddies, which are regions of vigorous upwelling become energized by hurricane winds. In extreme cases, the cold water that is rapidly upwelled from ~60 m depth can immediately weaken hurricanes by cutting off their energy before landfall. During the Deepwater Horizon oil spill, our SST tracking capabilities led to the discovery of eddy merging along the Loop Current margin, an event that significantly changed oil spill motion. 

Louisiana Coastal Surveillance

Mississippi River Diversions are an important component of coastal restoration efforts. Diversions introduce freshwater, sediment, and nutrients to the coast that are crucial for combating saltwater intrusion, marsh deterioration and land-loss.

At the ESL, image products have been developed which enable real-time and long-term surveillance of environmental parameters including sea surface temperature, suspended sediments, water mass color/type, and chlorophyll-a estimates. River water can be detected in our imagery as it is relatively low in temperature and sediment-rich. Time sequence images of the Mississippi River flood event of 2011 are also available. Algal blooms typically develop from the introduction of river borne nutrients into lakes/bays and the coastal ocean. The high levels of phytoplankton in tandem with strong stratification on the Louisiana shelf leads to the development of hypoxia each summer (Walker and Rabalais, 2006).  

High Resolution Coastal Flood Mapping

Hurricane-induced storm surges, waves, and rain can all contribute to widespread coastal flooding, particularly in low relief areas such as southeast Louisiana. Synthetic Aperture Radar (SAR) data provides measurements that can be used to map flooding. The SAR imagery is unaffected by cloud cover and is usable both day and night. In 2002, we began collaborating with researchers at NOAA NESDIS  Camp Springs, MD. (through the ADRO II project) and gained access to SAR images of coastal Louisiana during the two week episode when Tropical Storm Isidore and Hurricane Lili impacted coastal Louisiana's water levels. Subsequently, SAR imagery and SPOT multi-spectral imagery were employed in the study of coastal flooding from Hurricane Katrina.  Results were published in (Kiage et al., 2005). Funding for this research was provided mainly by the Louisiana Board of Regents

Hurricane Research

Real-time access to satellite measurements has enhanced LSU faculty research on hurricane processes, prediction, and coastal impacts. This capability has allowed researchers to estimate the radius of maximum winds using satellite measurements from the storm's eye, a measure that can be used to estimate wave height and storm surges (Hsu, 2005). Researchers have also been able to investigate the effects of dry atmospheric masses, cool water upwelling, and oceanic heat content on hurricane track and intensity changes. 

One study of oceanic conditions and mid to upper-level winds during Katrina (2005) and Rita (2005) demonstrated that both hurricanes experienced rapid intensification over Loop Current waters in the Gulf due to favorable upper level easterly winds in tandem with high oceanic heat content. In contrast to the 2005 hurricanes, a detailed analysis of Hurricane Ivan (2004) revealed that its intensity decreased as it crossed the Gulf due to dry air advection and a reduction in ocean energy due to cold water upwelllings, within large cold-core eddies along its track (Walker et al., GRL, 2005). Hurricane Ivan’s impacts on coastal shelf/slope circulation and on beach morphology changes were also assessed (Stone et al., 2005). Using higher resolution images from Radarat-1 SAR and SPOT we quantified the conversion of land to water in southeast Louisiana wetlands.

Deepwater Horizon Surface Oil Research

On April 20, 2010, the Deepwater Horizon oil rig experienced a series of malfunctions and subsequent explosions that disengaged the rig from its drill and killed eleven workers onboard. The explosion damaged the wellhead 5,000 feet below the surface, and crude oil flowed from the damaged wellhead until a containment cap was put in place on July 15, 2010.
The Earth Scan Laboratory tracked surface oil with several satellite sensors in near real-time. Our research of the event led to collaborations and publications on the oceanographic factors relevant to surface oil's fate as well as exposure effects for Gulf fishes.


Observations and Modeling to Advance a Louisiana Coastal Circulation and Oil Spill Prediction System

The BP Gulf Research Initiative is a collaboration between faculty and staff of LSU's School of the Coast and Environment, LSU Center for Computation and Technology (CCT) and the Naval Research Laboratory, Stennis (NRL) tasked with enhancing the state of Louisiana's ability to observe and model near-coastal circulation along the Louisiana coast for use within the state's broader oil spill prediction system. The project is comprised of four main components:
  1. Simulation modeling  will couple Finite Volume Coastal Ocean Module (FVCOM) bay modules to an enhanced FVCOM shelf module with offshore conditions provided by NRL's operational Intra-Americas Sea Nowcast/Forecast System for analysis of oil dispersion hind-casting.
  2. Wave-Current-Surge Information System (WAVCIS) information with be leveraged for validating component 1. WAVCIS is a real-time regional coastal observation system that operates six shelf stations to measure winds, waves, currents, temperature and salinity.
  3. The Earth Scan Laboratory (ESL) will provide surface oil areal estimates for validation of component 1. ESL capabilities were enhanced in 2014 to receive and process VIIRS measurements in near real-time.
  4. Provide integrated visualization capability for viewing, analyzing, and communicating results from model simulations and model-data integration intended for use by coastal resource managers and decision makers.