Scientists catch a hurricane transforming itself

Jan 30, 2006
NASA satellite image shows Hurricane Wilma

Hurricanes can completely re-structure themselves inside, and that presents forecasters with great uncertainty when predicting their effects on the general population.

Recently, scientists used data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite to analyze transformations that take place inside a hurricane. Stephen Guimond, a graduate research assistant at Florida State University, Tallahassee, Fla., lead a study that used TRMM data to view the height at which ice melts near the core of several tropical cyclones (the generic name for hurricanes or tropical storms), including Hurricane Ophelia in 2005.

"The temperature structure of a tropical cyclone is directly related to a storm's wind speed and rainfall, which indirectly affects the storm surge," Guimond said. It is important to monitor a storm's thermal structure because this information assists meteorologists in estimating the impact on threatened areas of high winds, flash flooding and large storm surge.

Many tropical cyclones transform into what are called "extra-tropical storms" as they move northward out of the tropics and into the mid-latitudes. During this stage, the storm's cloud structure and high winds spread out over a wide area. As a result, the potential for heavy rainfall and large storm surge increases far from the center, potentially affecting life and property of more areas in the hurricane's path.

When Guimond and his colleagues at the Naval Research Laboratory in Monterey, Calif. looked at the data from TRMM's Precipitation Radar instrument, they could see the temperature changes inside a tropical cyclone. One piece of information that gave researchers a clue that a storm was becoming extra-tropical was that ice particles, which are found high up in the cold regions of thick clouds surrounding the eye of the storm, melted at lower levels. Usually, when a tropical cyclone is still in the "tropical stages," ice particles melt higher in the clouds.

By analyzing when and where ice particles are melting in tropical cyclones, researchers can better understand the various stages of an extra-tropical storm. This knowledge will help scientists re-create storms on computer forecast models, which can assist in the forecasting of future tropical cyclone transformations.

There is another benefit to using the data from NASA's TRMM radar. Guimond said that the thermal or heat data inferred from the satellite reveals information on storm intensity and also gives clues about how a storm formed. This will help hurricane forecasters and researchers gain a better sense of how the tropical cyclone will develop in the future.

These findings were presented at the American Meteorological Society's 86th Annual Meeting in Atlanta.

Source: NASA

Explore further: Scanning Earth, saving lives

add to favorites email to friend print save as pdf

Related Stories

NASA Terra satellite spots new Tropical Cyclone 14S

Feb 24, 2015

A tropical low pressure area designated as System 90S formed in the Southern Indian Ocean on February 21, 2015 and has been slowly organizing and consolidating. Three days later System 90S became Tropical ...

NASA sees heavy rain in Tropical Cyclone Lam

Feb 20, 2015

Tropical Cyclone Lam made landfall in a remote area of the Northern Territory and the Tropical Rainfall Measuring Mission or TRMM satellite revealed that it brought heavy rain with it.

Recommended for you

Scanning Earth, saving lives

6 minutes ago

A high-speed camera for monitoring vegetation from space and combating famine in Africa is being adapted to spot changes in human skin cells, invisible to the naked eye, to help diagnose skin diseases like ...

How far back are we looking in time?

39 minutes ago

The Universe is a magic time window, allowing us to peer into the past. The further out we look, the further back in time we see. Despite our brains telling us things we see happen at the instant we view ...

THEMIS camera helps NASA pick site for next Mars lander

3 hours ago

NASA's next Mars space probe, a lander named InSight, is due to touch down on the Red Planet in September 2016 with a mission focused on the planet's internal properties. Its landing place has been chosen ...

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.