The real-time access to satellite measurements has enhanced LSU faculty research
on hurricane processes, prediction, and coastal impacts. In particular, recent research has focused on estimating the radius of maximum winds using
satellite measurements from the eye (1), which can be used to
predict wind, waves (2),(3) and storm
surge
(4).
Research has included investigations of the effects of dry masses on track and intensity changes (5),(6),
and on the effects of cool water upwelling and oceanic heat content on intensity changes along track (7),
(8), (9). A recent study of oceanic and mid- to upper-level winds during Ivan, Katrina, and Rita demonstrated that Katrina's and Rita's rapid intensifications over Loop Current waters in the Gulf was made
possible by favorable upper level easterly winds (8), (13).
Details of Ivans' impact on coastal/shelf/slope circulation and on beach morphology changes were assessed(3). Using higher resolution
images from Radarat-1 SAR and SPOT we have also developed techniques for detecting and quantifying hurricane-related coastal and urban flooding from Lili and Katrina
(10).
[1] Hsu, S.A., and A. Babin | Estimating the radius maximum winds via satellite during Hurricane Lili (2002) over the Gulf of Mexico, NWA Electronic Journal of Operational Meteorology 2005-EJ3.
[2] Hsu, S.A., Blanchard, B.W., and Martin, M.F., 2000. | An evaluation of
the USACE's deepwater wave prediction techniques under hurricane conditions during Georges in 1998. | Journal of Coastal Research, v. 16, no. 3, 823-829.
[3] Stone G.W, Walker N.D, Hsu S.A, Babin A., Liu B., Keim B.D., Teague W., Mitchell D., Leben R., Hurricane Ivan's Impact along the northern Gulf of Mexico, EOS Transactions, American Geophysical Union, Vol. 86, no. 48, 497,500-501, 2005.
[4] Hsu, S.A., | A wind-wave interaction explanation for Jelesniankski's open-ocean storm surge estimation using Hurricane Georges' (1998) measurements | National Weather Digest, v. 28, 25-31.
[5] Martin Jr., Melvin F, 2000. | The Relationship Between Water Vapor and Hurricane Track Using the GOES-8 Satellite. | PhD Dissertation, Louisiana State University, Baton Rouge, LA.
[6] Babin, A. | Characteristics of Hurricane Lili's intensity changes. | M.S. Thesis, Louisiana State University.
[7] Walker, N.D., Robert R. Leben, Shreekanth Balasubramanian | Hurricane-forced Upwelling and Chlorophyll a Enhancement within Cold-core Cyclones in the Gulf of Mexico | Geophysical Research Letters, v. 32, L18610, doi:10.102/2005GL023716.
[8] Walker et. al., 2006 | pdf
[9] Walker N.D, Haag, A., Balasubramanian S., Leben R., Van Heerden I., Kemp P., Mashriqui H. | Hurricane Prediction: A Century of Advances | Oceanography | Vol. 19, No. 2, 24-36, June 2006
[10] Kiage L.M, Walker N.D, Balasubramanian S., Babin A., Barras J., Applications of Radarsat-1 synthetic aperture radar imagery to assess hurricane related flooding of coastal Louisiana, International Journal of Remote Sensing Vol 26 (24), 5359-5380. Featured image Flooding of New Orleans. Cover page IJRS Vol 26 (24).
[11] Hsu, 2003 | article
[12] Blanchard B. and Hsu, S.A | On the radial variation of the tangential wind speed outside the radius of maximum wind during Hurricane Wilma (2005) | NWA Electronic Journal of Operational Meteorology 2006-EJ4
[13] Hsu, S.A.,, Braud, DeWitt, Blanchard B. | Rapid Estimation of Maximum Storm Surges Induced by Hurricanes Katrina and Rita in 2005 | NWA Electronic Journal of Operational Meteorology 2006-EJ9
P.I: Prof Nan Walker
The Gulf Loop Current is one of the most dynamic ocean currents in the world. Frontal eddy cyclones, regions of vigorous upwelling, develop along its margin in association with current meanders,
increasing current speeds and impacting flow even in 3000 m of water. At irregular intervals, large warm eddies separate from the Loop Current and move westward, dissipating over many months along the
Texas and Mexican coasts. The Loop Current and its eddies are large reservoirs of heat that have the capability to intensify hurricanes and tropical storms crossing the Gulf. Using infrared
measurements from the GOES-East satellite, a "cloud eraser" was developed that has enabled us to track and study the frontal eddy cyclones that move rapidly (35 km/day) around the margin of the
Loop Current. More recently we have been integrating GOES sea surface temperature data with satellite sea surface height data (from Dr. Robert Leben, CCAR) to improve our capabilities for studying the
complex eddy field in the Gulf. Our funding for this research comes mainly from the Minerals Management Service. Visit the SST/SSH image archives and animation page. Publications of interest include
Walker et al. (2003), Walker et al. (2005) , and Walker et al. (2006).
Image Archives of Interest
Gulf of Mexico GOES SST/SSH products (daily, weekly and movie loops)
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PI : Prof Nan Walker
The Louisiana coastal ocean receives discharges from the Mississippi and Atchafalaya Rivers, through the bird-foot delta and through Atchafalaya Bay. In
addition, river diversions have been built to re-introduce river waters and sediments into coastal bays, lakes and wetland areas. Funding from NASA and NOAA
are being used to develop remote sensing tools for the study of processes related to these river inputs including sediment transport, algal blooms and hypoxia
along the coast. In support of coastal research and management, a range of real-time satellite image products from MODIS, OCM, and NOAA AVHRR have been
developed and are accessible below. Publications of interest include Walker (1996), Walker and Hammack (2000), Walker (2001) , Myint and Walker (2002), Walker et al. (2005), Walker (2005).
Mississippi and Atchafalaya River Plumes
River Deltas of the World: a baseline and changes
P.I.s : Profs. Oscar Huh and James Coleman
Coincident with the launching of the Earth Observing System is the accumulation
of more than 21 years of earth observations by the Landsat spacecraft, which
delivers images from the multispectral Thematic Mapper at 30m resolution.
This archival record encompasses two decades of change on these dynamic land
forms.
more...
Image Archives of Interest
AVHRR Image Products
MODIS True Color Archive
OCM Chlorophyll Imagery
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PI: Prof Nan Walker
Hurricane-induced storm surges, waves, and rain can all contribute to widespread coastal flooding, particularly in low relief areas such as southeast
Louisiana. The Synthetic Aperture Radar (SAR) on the Radarsat-1 provides a powerful source of data for mapping flooding as it is unaffected by cloud cover and
usable both day and night. In 2003, we began collaborating with researchers at NOAA NESDIS, Camp Springs, MD. (through the ADRO II project) and gained access
to many SAR images of coastal Louisiana during the two week episode when Tropical Storm Isidore and Hurricane Lili impacted coastal Louisiana's water
levels. More recently, SAR imagery and SPOT multi-spectral imagery were employed in the study of coastal flooding from Hurricane Katrina. Our initial results
have been published (Kiage et al., 2005). Funding for this research has been provided mainly by the Louisiana Board of Regents.
Published figures in the final paper:
Flooding of New Orleans, SPOT and SAR
MultiTemporal False Composite Image
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