Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An Active Florida Hurricane Season Adds to Red Tide

01.08.2006
Scientists believe that Florida's very active 2004 hurricane season may have played an important part in the development of extensive and long-lasting red tide conditions that affected its coastal areas in 2005.

The four hurricanes that crossed the Sunshine State in August and September 2004 dumped as much as 27 inches of rain (nearly double the historical values) in central Florida, which increased groundwater levels and rates of surface runoff. These two factors are thought to create conditions ripe for the bloom of a red tide.

Red tides, which may or may not be harmful, are primarily caused by the toxic phytoplankton, Karenia brevis on the west Florida Shelf. This species of phytoplankton can produce toxins that can kill marine organisms and lead to irritation of the eye and respiratory systems of animals and people.

Scientists Chuanmin Hu and Frank Muller-Karger of the University of South Florida, St. Petersburg, Fla., and Peter Swarzenski of U.S. Geological Survey, St. Petersburg, Fla., noted that several factors may have contributed to the 2005 red tide: the 2004 hurricanes and their heavy rain, runoff, and submarine (below the ocean floor) groundwater discharge. The scientists used NASA satellites, as well as observations from ships, buoys from the National Oceanic and Atmospheric Administration (NOAA), and geochemical tracers to study red tide.

During the 2004 hurricane season, four hurricanes crossed the state of Florida: Charley, Frances, Ivan and Jeanne. According to NOAA's National Hurricane Center, radar estimates of Charley's rainfall over central Florida were between six and eight inches. Frances produced rainfall in excess of ten inches over large portions of the central and northern Florida peninsula. Ivan produced rainfall totals between three and seven inches in a swath that included Alabama and the Florida panhandle. Finally, Jeanne produced widespread rainfall of up to eight inches across eastern, central and northern Florida, with 11 inches over extreme northeast Florida.

Red tides occur in the same area off west-central Florida almost every year, mostly between August and March, from north of Tampa to south of Naples, Fla. The 2005 red tide poisoned the ocean waters and killed fish, turtles, birds, and marine mammals. This red tide was unusual because it lasted an entire year.

"Runoff alone provided insufficient nitrogen to support this bloom," said Hu. "Submarine groundwater discharge injects water coming from the water table underneath Florida into the ocean through the ocean floor, below the ocean's surface and off the coast. We believe that submarine groundwater discharge provides the missing nutrients, and may trigger and maintain red tides off west-central Florida." Hu and his colleagues proposed that the unusual number of hurricanes in 2004 resulted in high runoff, and in higher than normal discharge of groundwater that was deposited along the west Florida coast throughout 2005. The groundwater discharge may also explain why the red tides happen in the same area almost every year, but also why they happen in other coastal regions of the Gulf of Mexico, Hu and Swarzenski said.

In the past, hurricanes were thought to dissipate red tides. However, a series of hurricanes in summer 2005, including Hurricane Dennis (landed near Florida’s Panhandle on July 10, 2005) and Hurricane Katrina (landed in south east Louisiana on August 29, 2005), only caused significant water mixing, and storm surges where dead fish were washed ashore. After sediment settled on the ocean floor, the red tide appeared even more extensive.

NASA's MODerate Imaging Spectroradiometer (MODIS) Instrument aboard NASA's Terra and Aqua satellites, and NASA and GEOEye’s Sea-viewing WIde Field-of-view Sensor (SeaWiFS) on the OrbView-2 satellite were used to detect the red tide blooms in December 2004. By the end of that month, MODIS showed that the bloom covered 425 square miles (1,100 square kilometers (km2)) immediately off Tampa Bay. By late September 2005 the bloom expanded to approximately 26,062 square miles (67,500 km2).

Submarine groundwater in Tampa Bay has been shown to be a larger nutrient source than local rivers. There are also numerous submarine springs off the Florida coast and some are located near where red tides occur every year. Hu, Muller-Karger and Swarzenski suggest that frequent hurricanes result in elevated rainfall that leads to an increase in the surface runoff and possibly discharge of submarine groundwater, which lead to a larger, persistent red tide event.

The study was published June 1 in the journal of Geophysical Research Letters.

Rob Gutro | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/centers/goddard/news/topstory/2006/hurricane_redtide.html

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>