Music.
Music
Rob: We have an energy question today. Can you tell us about the energy within a hurricane?
Jeff: The energy in a hurricane comes from the ocean. Of all
the places, who would think, but the really warm water in the ocean,
that causes the water to evaporate. And when
these molecules leave the surface of the water, they take some heat energy with them, and
as that heat energy gets up into the hurricane, those water vapor
molecules condense and they release their heat into the atmosphere.
And that's how the hurricane gets its power. That warm air we see in the
center of the storm--the eye--that comes from the ocean basically.
Rob: Is there a name for that heat? Jeff: That's called latent heat because
latent means it's kind of hidden. So you can't put a thermometer in it and measure it directly,
but it's in those molecules. They're like little mobile solar collectors.
Rob: And what happens to the energy after the hurricane is dissipating?
Jeff: So the top of the hurricane behaves like a giant radiator in
an engine. It's warmer than its surroundings because of all that heat
and it just radiates it out to space. Narrator: Researchers from
NASA and the National Oceanic and Atmospheric Administration work from both
in the air and on the ground, investigating the energy needed to form hurricanes,
as well as the energy hurricanes release. Looking at these factors
may help scientists better predict the strength and paths of the storms
ensuring the safety of people everywhere. While NASA and NOAA work all around the
globe studying hurricanes, here's a classroom activity that lets us look at
real hurricanes and make some observations of our own.
This activity from My NASA Data allows students to examine sea surface
temperature to explore how hurricanes extract heat energy from the ocean's
surface. In this exercise, we have access to data
and images that researchers and satellites have gathered on Hurricane Rita,
a Category 5 hurricane that tore through the Gulf of Mexico in September 2005.
If we want to look at energy on a large scale, this is a
good place to start. Here, we're looking at the period during
and right after Hurricane Rita, using data from the GOES and Aqua satellites
which provide information on clouds and infrared energy from the ocean's
surface. We'll be creating a time series of images of the Gulf
of Mexico in order to investigate sea surface temperature changes in the wake
of a hurricane. Hurricanes cause a large transfer of heat between
the ocean's surface and the atmosphere. They also cause upwelling,
which is ocean circulation that brings cold, deep water to the surface.
We see these effects in a dramatic decrease in sea surface temperature,
a trend that can last for a week or longer after the storm.