Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellites give an eagle eye on thunderstorms

16.12.2010
It's one of the more frustrating parts of summer. You check the weather forecast, see nothing dramatic, and go hiking or biking. Then, four hours later, a thunderstorm appears out of nowhere and ruins your afternoon.

Thunderstorms can bring intense rain, hail, lightning and even tornadoes, but "predicting them a few hours out is one of the great problems of meteorology," says Chian-Yi Liu, a postdoctoral researcher at the University of Wisconsin-Madison.

And the consequences can be more serious than a rained-out hike — even major storms can be missed, Liu says, including the one that dumped up to 10 inches of rain on La Crosse, Wis., on Aug. 18, 2007. "Predictions for the day said a moderate chance of thunderstorms," Liu says, "but this one produced an inch or two of rain per hour and caused severe flooding."

Thunderstorms are called "convective storms" because they are powered by differences in air density that cause updrafts and cooling, and can lead to hail, rain, tornadoes and lightning.

In a presentation at the meeting of the American Geophysical Union in San Francisco on Dec. 16, Liu will show that additional data, taken from a satellite, could greatly improve the accuracy of thunderstorm prediction a few hours out.

Liu works at the Cooperative Institute of Meteorological Satellite Studies (CIMSS) at UW-Madison, which both processes satellite data and explores how meteorologists can use more effectively.

"Scientists understand the basic causes of thunderstorm formation," Liu says, "but their major source of data is usually surface observations, or measurements taken from balloons that are released into the lower atmosphere, and they usually lack information about the upper atmosphere."

When Liu and his colleagues introduced data on conditions at 15,000-32,000 feet of altitude into the equation, they found a considerable improvement in the crucial three- to six-hour forecast. The data was collected from 400 different events by sensors on NASA's Aqua satellite that measure conditions at different altitudes.

Convective storms allow the atmosphere to dump excess energy, held in the form of heat and humidity, and release it as wind and especially precipitation. Convection storms are most likely when the atmosphere is unstable, Liu says. "Our analysis shows that if there is instability at around 30,000 feet, with other storm-favorable conditions, a convective storm will develop in the following three to five hours. Using the top-down view of a satellite reverses our usual way of thinking about convective storms, and may suggest an explanation for storms that arise when they would not be predicted using conventional methods."

"For a long time, we have looked at convection and instability from a near-surface perspective," says co-author Steve Ackerman, a professor of meteorology and director of CIMSS. "What Chian-Yi has showed is that this is not always the case, you can drive instability from upper troposphere too."

The troposphere is roughly the lower six miles of the atmosphere.

Convection releases energy and feeds on itself, Ackerman says. "If you have unstable conditions in the atmosphere and things get moving, they will continue to move by themselves. Our perspective has been how it could get started from the ground. Chian-Yi has shown that it can start from the top as well."

CIMSS has a good working relationship with National Weather Service, Ackerman says, and has a "proving ground" process that can quickly incorporate research results into forecast methods.

"In my experience, there are not many advances that come along with so much potential to improve forecasts," Ackerman says. "This is an advance in the science, and it takes this perspective: Let's not always look at the atmosphere from the ground. Let's also look at what happens in the upper atmosphere."

Chian-Yi Liu | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Earth Sciences:

nachricht Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington

nachricht Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>