Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA research shows wetland changes affect Florida freezes

19.11.2004


Scientists funded by NASA and the U.S. Geological Survey (USGS), used Landsat 5 satellite data to look at changes in wetlands areas in south Florida, particularly south and west of Lake Okeechobee.



Using satellite data, land-cover change history, computer models, and weather records, the researchers found a link between the losses of wetlands and more severe freezes in some agricultural areas of south Florida. In other areas of the state, changes in land use resulted in slightly warmer conditions. They concluded, based on the study, the conversion of wetlands by itself may be enough of a trigger to enhance damage inflicted upon agriculture in these areas of south Florida during freezes events.

The Landsat 5 satellite was constructed and launched by NASA, and its data are processed and distributed by the USGS. The researchers studied three freeze events and simulated the conditions with a computer climate model, using weather and land-cover change records. The freezes took place on December 26, 1983, December 25, 1989, and January 19, 1997.


The study, authored by Curtis Marshall and Roger Pielke of Colorado State University (CSU), Fort Collins, Colo., and Louis Steyaert of the USGS and NASA’s Goddard Space Flight Center, Greenbelt, Md. appeared in a recent issue of the American Meteorological Society’s Monthly Weather Review.

The researchers found a strong tie between areas that were converted from wetlands to agriculture use during the 20th century, and those that experienced colder minimum and longer duration subfreezing temperatures in the current land-use scenario. Water typically doesn’t cool as quickly as the land at night, which may explain why when wetlands are converted to croplands the area freezes faster and more severely. "The conversion of the wetlands to agriculture use itself could have resulted in or enhanced the severity of recent freezes in some of the agricultural lands of south Florida," Marshall said. He noted some other areas also experienced warming from land changes.

The study focused on "radiation freeze events" that occur at night, frequently under calm wind conditions and when there is little or no cloud cover. At night much of the warmth absorbed by the land during the day escapes into the atmosphere, cooling the ground.

This study of wetland changes is very important to Florida and the rest of the country. Over the past 150 years, the citrus industry has been moving further south. As a result more wetlands are being transformed into agricultural lands, and these changes are causing temperatures to change. Ironically, as the industry moves further south to avoid freezes, the land changes create the conditions the industry is trying to avoid.

The scientists analyzed land-cover changes over the past 100 years in Florida based on reconstructed pre-1900 natural vegetation data and land-cover data derived from early 1990s Landsat images. They input land-cover and weather record data into the CSU Regional Atmospheric Modeling System and re- created the conditions for the three freezes.

In all three cases, the most densely cultivated areas were colder and also experienced subfreezing conditions for a longer period of time. Those areas include south and southwest of Lake Okeechobee and other key agricultural areas in the Kissimmee River valley.

Gretchen Cook-Anderson | EurekAlert!
Further information:
http://www.gsfc.nasa.gov

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Researchers devise microreactor to study formation of methane hydrate

23.08.2017 | Materials Sciences

ShAPEing the future of magnesium car parts

23.08.2017 | Automotive Engineering

New insights into the world of trypanosomes

23.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>