Satellites Spot Mighty Mississippi – In The Atlantic

Sep 15, 2005
Satellites Spot Mighty Mississippi – In The Atlantic 1

Scientists using satellite imagery found that at least 23 percent of the water released from the mouth of the Mississippi River from July through September 2004 traveled quite a distance - into the Gulf of Mexico, around the Florida Keys, and into the Atlantic Ocean.

Image: Phytoplankton appear as brilliant streaks of blue and green over the South Atlantic Ocean in this image from the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite on January 4, 2005. Credit: NASA GSFC

The researchers combined data from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra and Aqua satellites with information collected from ships to study the water discharge, appearing as a dark plume that stretched from the Mississippi Delta, around Florida and up to the Georgia coast. MODIS detects the color of the ocean due to changes in the amount of tiny ocean plants floating on the ocean's surface known as phytoplankton, or algae and other decaying materials.

"This is the first time we have been able to estimate the amount or volume of freshwater discharged and carried over such remote distances. By combining the very detailed data from MODIS with observations from ships, we got a three-dimensional view of the Mississippi plume," said Chuanmin Hu, of the College of Marine Science, University of South Florida, St. Petersburg, Fla., and lead author of the study. By using MODIS data with information on sea surface currents and sea salt levels (salinity), the scientists estimated that about 20 billion tons of Mississippi River water reached the Florida Straits and Gulf Stream off the Georgia coast. This is about four times the volume of Lake Okeechobee, the largest lake in Florida.

Satellites Spot Mighty Mississippi – In The Atlantic

Image right: This image from MODIS aboard NASA’s Terra satellite shows the murky brown water of the Mississippi River mixing with the dark blue water of the Gulf of Mexico two days after a rainstorm. Credit: NASA NASA/University of Wisconsin-Madison

The research also shows that such plumes created by the Mississippi River can travel over large distances, more than 1240 miles (2000 kilometers).

Beyond studying the causes of such events, researchers are using satellite information with observations from ships and "ocean surface drifters" - instruments resembling balloons that travel the ocean surface, to get a better idea of how these plumes affect marine life.

"Mississippi River water may have some impact on marine life in remote delicate ecosystems like the Florida Keys. But we are still not clear about the potential impacts of pollutants and pesticides," said Hu. "Not all effects will be bad; in fact, some light dark water events might actually protect bottom ocean dwellers, like coral, by providing them with shade."

The study is published in the July 2005 issue of Geophysical Research Letters under support of NASA, NOAA, and ONR as a contribution to the SouthEast Atlantic Coastal Ocean Observing System (SEACOOS). Coauthors include oceanographers James Nelson from the Skidaway Institute of Oceanography, Elizabeth Johns from NOAA’s Atlantic Oceanographic and Meteorological Laboratory, and Zhiqiang Chen, Robert Weisberg, and Frank Muller-Karger from the University of South Florida.

by Mike Bettwy, Goddard Space Flight Center

Explore further: Video gives astronaut's-eye view inside NASA's Orion spacecraft

add to favorites email to friend print save as pdf

Related Stories

Too wacky? Moving water from flood to drought

Sep 09, 2011

(AP) -- As the soggy East tries to dry out from flooding and Texas prays for rain that doesn't come, you might ask: Isn't there some way to ship all that water from here to there?

Scientists find average but large Gulf dead zone

Aug 04, 2014

NOAA- and EPA-supported scientists have mapped the Gulf of Mexico dead zone, an area with low oxygen water, measuring 5,052 square miles this summer—approximately the size of the state of Connecticut. The ...

Recommended for you

SDO captures images of two mid-level flares

Dec 19, 2014

The sun emitted a mid-level flare on Dec. 18, 2014, at 4:58 p.m. EST. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts ...

Why is Venus so horrible?

Dec 19, 2014

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

Dec 19, 2014

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

Dec 19, 2014

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.