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New Satellite Tools Putting Hurricanes In Sharper Focus

Date:
August 31, 1999
Source:
University Of Wisconsin-Madison
Summary:
A fleet of powerful new visualization tools is giving forecasters an unprecedented look into the anatomy of typhoons and hurricanes, helping refine early-warning systems.
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MADISON - A fleet of powerful new visualization tools is giving forecasters an unprecedented look into the anatomy of typhoons and hurricanes, helping refine early-warning systems.

Beyond better resolution, these satellite-based tools are helping scientists break tropical cyclones down into their component parts, dissecting some of the forces that create, fuel and steer these dangerous storms.

"What we're doing is fusing together images through the use of multiple satellites," says Chris Velden, a tropical cyclone researcher at the University of Wisconsin-Madison. "Each satellite has its own view of the earth, and we're piecing many of them together for a more complete picture."

This "data fusion" technique is the source of several new hurricane forecasting methods developed at UW-Madison that are in daily use at the National Hurricane Center in Miami and the Joint Typhoon Warning Center in Pearl Harbor.

The bank of images is publicly available on the web site of UW-Madison's Cooperative Institute for Meteorological Satellite Studies (CIMSS) tropical cyclone team, a group led by Velden. Visitors can peruse recent and real-time movies and images of current tropical storms Dennis, Emily and Cindy, or any current cyclone in the Atlantic or Pacific Ocean.

Visit: http://cimss.ssec.wisc.edu/tropic/tropic.html

Velden says the new tools are designed to shed light on two of the biggest unknowns about tropical cyclones: Where they originate and how they gather and lose intensity. Just in the past five years, satellite technology has improved forecasting of the path of storms, but estimating their power has been difficult.

One new product introduced this year, called Wavetrak, combines data from five different satellites to create a 10-day movie loop of atmospheric waves sweeping out of central Africa, the birthplace of cyclones. Wavetrak is designed to study the atmospheric waves that act as a conveyor belt for conditions that cause cyclones.

"We're grappling with how and where these waves originate, because about one in every ten will form into a named tropical storm," Velden says. "This shows us the amplitude and strength of these waves as they come off Africa and into the Atlantic."

Wavetrak, created by Velden and research intern Jason Dunion, gives scientists a complete picture of a cyclone - from its birth over central Africa, growth across the Atlantic and eventual fizzling out. It shows the succession of atmospheric waves moving along "like cars on a train."

The technology has great benefit in seeing the genesis of storms. "It gives us an idea of exactly where they initiate over the African continent and their convective structure as they track over the ocean."

On the question of measuring tropical cyclone intensity, the CIMSS team has a number of products in use by forecasters. One product is helping provide a better handle on wind shear, an important predictor of intensity.

Wind shear is essentially the difference in speed between high-level and low-lying winds. A strong wind shear will slice the tops off of cyclones and slash their power. The CIMSS site provides a multi-colored map, which uses high-resolution satellite observations updated every 3 hours, that shows the levels of wind shear across the Atlantic.

It gives forecasters a highly visual record of wind shear patterns that will either break up or add fuel to a storm. Velden says scientists want to pinpoint the thresholds of wind shear effects, good or bad, on cyclones.

Other CIMSS tools to track hurricane intensity include:

* The Objective Dvorak Technique.


Story Source:

Materials provided by University Of Wisconsin-Madison. Note: Content may be edited for style and length.


Cite This Page:

University Of Wisconsin-Madison. "New Satellite Tools Putting Hurricanes In Sharper Focus." ScienceDaily. ScienceDaily, 31 August 1999. <www.sciencedaily.com/releases/1999/08/990831080525.htm>.
University Of Wisconsin-Madison. (1999, August 31). New Satellite Tools Putting Hurricanes In Sharper Focus. ScienceDaily. Retrieved March 27, 2024 from www.sciencedaily.com/releases/1999/08/990831080525.htm
University Of Wisconsin-Madison. "New Satellite Tools Putting Hurricanes In Sharper Focus." ScienceDaily. www.sciencedaily.com/releases/1999/08/990831080525.htm (accessed March 27, 2024).

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