Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA Looks at Hurricane Cloud Tops for Windy Clues

18.05.2006


Scientists at NASA are finding that with hurricanes, they can look at the cloud tops for clues about the behavior of winds below the hurricane on the Earth’s surface.



By looking at how high up the rain is forming within clouds, scientists can estimate whether the hurricane’s surface winds will strengthen or weaken. They have found that if rain is falling from clouds that extend up to 9 miles high, and that rain continues for at least one out of three hours, a hurricane’s surface winds are likely going to get stronger.

To see into the cloud tops, NASA scientists developed a precise mathematical method or a technique with the very precise rain measurements from the radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite. Once this technique was developed it was applied to data collected by National Weather Service radars on the ground.


"Thanks to the precise measurements from TRMM, we’ve found a new way to use data that’s collected all the time by weather radars on the ground," said Owen Kelley, scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md.

Kelley and scientists John Stout of NASA Goddard and Jeff Halverson of the University of Maryland Baltimore County calculated statistics that suggest forecasters could use TRMM’s rain-height observations to improve existing observations and computer model forecasts of hurricane winds. "The trick is to keep an eye on the height of rain that radars see when a hurricane approaches within 200 miles of the coast," Kelley said.

The TRMM satellite and the ground radar work well together, especially during hurricanes because they each have an advantage. National Weather Service radars on the ground give less precise height measurements of rainfall than the TRMM satellite’s radar, but ground radars can continuously observe a nearby hurricane for hours at a time, whereas TRMM’s orbit prevents it from hovering over one spot.

For several years, Kelley and his colleagues have been studying "hot towers," the towering high clouds in a hurricane’s eyewall. The eyewall is the area of strong storms that surround a hurricane’s mostly cloud-free eye. Hot towers can generate very heavy rainfall and reach the top of the troposphere, which extends 9 miles (14.5 km) above the Earth’s surface in the tropics. These towers are called “hot” because a lot of heat is released inside them by water vapor condensing to form rain.

Hot towers are one window into the mystery of how hurricanes grow stronger. A single hot tower does not tell you much about a hurricane, but a rapid sequence of towers suggests that something unusual is going on deep inside the hurricane.

By combining measurements from many hurricanes, statistics show that if hot towers exist in the eyewall at least 33% of the time during a three-hour period, a hurricane’s destructive surface winds have an 82% chance of intensifying. Otherwise, the chance of wind intensification drops to only 17%. The bottom line is that if several hot towers are present in a hurricane over a period of time, there’s a higher probability of a storm intensifying.

Kelley is still searching for a more complete explanation of what causes these bursts of hot towers. Radar observations have shown conclusively that these bursts happen, but further research is needed to explain why and how.

TRMM, which was built by NASA and the Japan Aerospace Exploration Agency, and launched in 1997, has been orbiting the Earth watching rainfall from space.

This study appeared in an issue of Geophysical Research Letters in the fall of 2005. During the 2006 hurricane season, researchers both inside and outside NASA will continue to use TRMM to shed light on how hurricanes work.

Rob Gutro | EurekAlert!
Further information:
http://www.nasa.gov/vision/earth/lookingatearth/eyewall.html

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

A better way to measure the stiffness of cancer cells

01.03.2017 | Health and Medicine

Exploring the mysteries of supercooled water

01.03.2017 | Physics and Astronomy

Research team of the HAW Hamburg reanimated ancestral microbe from the depth of the earth

01.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>