Table Of Contentand Other Disaster Heroes
A digital companion to Disasters
™
From tornado-chasing scientists to blaze-battling firefighters,
a host of men and women risk their lives on a daily basis
to help us avoid being caught up in natural disasters —and to
rescue us when we are. Click on a button to discover more
about the heroes and heroines of disaster.
Storm chasers [Looking for twisters]
Tornadoes —violently rotating columns of air that strike with
little warning but devastating impact—are among the most
spectacular natural sights on Earth. Many people risk life and
limb to seek out these twisters and watch them being born
Daredevil photographer
from vast storm clouds called supercells. Some of these storm Mike Hollingshead took this
photo of a tornado beneath
chasers are photographers and filmmakers hoping to capture
a supercell in Nebraska.
the shot of a lifetime. Others, such as the meteorologists of Hollingshead follows extreme
weather across the country,
the VORTEX2 project, aim to capture data that will shed light
covering 20,000 miles (32,000
on the conditions that create tornadoes. km) as he photographs about
40 storms each year. “All the
other levels of storms below
the truly crazy ones, I just
don’t care a lot for,” he says.
Dangerous work
Storm chasers may face winds
powerful enough to toss cars
into the air. They may also be
“
bombarded by hailstones the
I can’t remember ever not size of golf balls, which can
smash a car’s windows and
wanting to witness severe „
dent its body.
weather—every waking
minute if it were possible!
—Roger Edwards, meteorologist
and storm chaser
VORTEX2 crew
Members of the VORTEX2 project
watch a storm developing in Kansas
in June 2009. VORTEX2 studied
tornadoes using a number of methods,
including mesonets and a special
type of radar called Doppler radar.
VORTEX2 [Data detectives]
Launching a weather balloon
Over 100 scientists and students and 50 vehicles from VORTEX2 spent the
tornado seasons of 2009 and 2010 chasing storms throughout the Midwest.
The data they collected will help meteorologists improve tornado forecasting
and understand why some tornadoes are destructive but others are not. A
similar project, Rotate 2012, ran in May and June of 2012.
Directing operations Deploying
a stick net
Erik Rasmussen monitors
developing storms in the FC.
When the team was out storm chasing, information from weather The VORTEX2 team set up large numbers of stick nets in the paths Two members of the VORTEX2 team prepare to launch a weather
sensors was analyzed inside the field command unit, or FC. The FC of storms. Attached to tripods, these portable weather stations record balloon. Equipped with sensors, balloons like this collect
then directed the other vehicles as they tried to intercept the storm. wind speed, temperature, humidity, and air pressure. weather data at high altitudes near developing storms.
Positioning a mesonet Scanning with Doppler radar Planning the next step
A mobile mesonet is a kind of weather station on wheels. It carries a Doppler radar units told the VORTEX2 meteorologists about the shapes Scientist Paul Markowski is shown explaining how the team will
range of sensors similar to those on a stick net, but since it is mounted and movements of supercells. The units are carried on rugged trucks so use Doppler radar to try to catch fast-moving storms the next day.
on a vehicle, it can be moved very rapidly to follow or intercept a storm. that they can be maneuvered as close as possible to a storm. Red areas on the map show the scanning range of the radar units.
.
The TIV-2 is an armor-plated Dodge 3500 pickup From 2007 until 2011, Sean Casey starred in Casey chased his first storm in the late 1990s.
truck with a camera turret, weather sensors, bulletproof the TV show Storm Chasers, which ran for five “During the first chase, I fell in love with the experience,”
windows, and drop-down metal “skirts” that keep the seasons. Here he is shown being interviewed he says. He adds that after the wind, hail, and lightning
wind from blowing underneath and turning it over. by a Discovery Channel camerawoman. were over, “I desperately wanted to keep chasing.”
Sean Casey
Casey hopes
A filmmaker and professional storm chaser, the best protection possible against the
that his work will
not only amaze Sean Casey became famous as one of the most violent storms. “We need a vehicle
and inform the stars of the Discovery Channel’s reality TV that can get in front of these tornadoes and
public, but also show Storm Chasers. film them and have trees crash around us
help scientists
and feel okay about that,” he says. As a
understand
Casey’s interest in storm chasing began result, he built two armor-plated Tornado
tornadoes better.
when he read a book on the subject to pass Intercept Vehicles (TIVs). Using the TIVs,
the time while making a nature film Casey spent eight years collecting footage
on an isolated Pacific island. Casey of tornadoes, hailstorms, and supercells. He
decided he wanted to show the raw also filmed VORTEX2 teams in action as
power and beauty of tornadoes they chased storms across the Midwest. In
in an IMAX movie. (IMAX is a 2011, his IMAX movie Tornado Alley was
way of making movies that can released to great acclaim.
be projected onto enormous
screens in special theaters.) When asked about his scariest storm-
chasing moments, Casey says: “It’s when
In order to achieve his goal, we’ve lost control of the situation and
Casey knew he needed find ourselves being chased by a violent
an ultra-rugged vehicle tornado that we don’t want to be hit by,
that would give him but can’t outrun.” That’s very scary!
“ „
We usually start filming when we
can hear the roar of the tornado.
—Sean Casey
Supercell
A supercell is an intense, long-lasting thunderstorm that contains
a continuously rotating updraft of air. Supercells typically have
a lifespan of about three hours, but some rage for as long as six.
They cause severe weather, including huge hailstones, torrential
rain, and strong winds—and sometimes even tornadoes.
Supercells usually occur when warm, humid, low-pressure air is
below a cooler upper layer. As the warmer air rises and the colder air
descends, the interaction between the warm updrafts and the cool
downdrafts generates a spinning column of warm air.
Larger supercells sometimes produce tornadoes, especially
during warmer times of the year. The base of a supercell has a
low, usually rotating bulge known as a wall cloud, which hangs
beneath the broader cloud layer above. It is from the wall cloud
that tornadoes may develop.
Only about 30 percent of supercells produce tornadoes. However,
when they do occur, supercell tornadoes are often extremely violent,
with winds that can exceed 200 miles per hour (320 kph), and they
may stay in contact with the ground for an hour or more. A single
supercell thunderstorm can generate several tornadoes.
(21,000 m)
the height of the clouds in the tallest supercell thunderstorms
Doppler radar
Radar stands for RAdio Detection And Ranging. A radar unit
sends out a beam of microwaves (short-wavelength radio waves)
and collects the “echoes” that bounce back off distant objects.
Since radio waves travel at a constant speed—about 186,000 miles
(300,000 km) per second—the distance to an object can be
determined by measuring the time it takes for the echoes to return.
Storm chasers, such as the meteorologists of VORTEX2 and Rotate
2012, use a type of radar called Doppler radar.
Doppler radar shows not only the distance and position of an object,
like conventional radar does, but also whether it is moving toward
or away from the radar unit and how fast it is traveling. This is
determined by using the Doppler effect—the fact that waves coming
toward the unit have a different pitch than those moving away. In
storm chasing, the echoes from water droplets in an approaching
storm cloud have a higher pitch than echoes from water droplets in a
cloud traveling in the opposite direction do.
Doppler radar works over a smaller area than conventional radar does,
so storm chasers have to mount their Dopplers on vehicles to get
within range of supercells. Using Doppler radar, meteorologists can
determine the size, shape, and movement of a supercell, measure
air movements inside it, and detect tornadoes forming. The NOXP
(shown at left) is a special kind of Doppler radar unit that tells storm
chasers where and how much rain is falling.
currently, the average time between hearing
a warning and being struck by a tornado
meteorologist
noun
A weather scientist. Meteorologists study the chemical and physical
qualities of the atmosphere and the dynamic processes that create
the world’s weather. Many meteorologists work in weather centers,
monitoring weather systems as they develop, issuing daily forecasts,
and warning the public of potentially dangerous weather events.
Climatologists are meteorologists who analyze the long-term weather
patterns known as climate. They not only study the present climate
but also investigate how Earth’s climate was different in the past and
consider how it may change in the future.
mesonet
noun
A weather station designed to study mesocale events—that is,
medium-size weather systems that are smaller than hurricanes
and cyclones but larger than local thunderstorms. A supercell is an
example of a mesoscale event.
A mesonet includes an array of weather sensors to record data
on wind speed, humidity, air pressure, and temperature. Both the
VORTEX2 and Rotate 2012 projects used mesonet arrays attached
to cars and trucks to create mobile weather stations that could
follow supercells and tornadoes.
Hurricane hunters
Each year between June and November, the men and women of
the 53rd Weather Reconnaissance Squadron (WRS)—part of the US
Air Force Reserve—risk their lives and fly directly into the hearts
of hurricanes. Known as the Hurricane Hunters, they gather as
much data as they can on these vast, wild tropical storms, which
can devastate coastal regions. The information that the Hurricane
Hunters collect in their Lockheed Martin C-130J aircraft helps Airborne sensor
When a C-130J flies into a
meteorologists make more accurate forecasts, so people can be
hurricane, it launches sensors
evacuated from the paths of storms and lives can be saved. called dropsondes. As the
dropsondes descend through the
storm by parachute, they relay
100 million: vital data about conditions inside
the storm back to the plane.
the approximate number of Americans
at risk from hurricane strikes
Storm warnings
If weather satellites detect
a tropical storm, the National
Hurricane Center (NHC) in
Miami, FL, contacts the 53rd
WRS so that the Hurricane
Hunters can go up to investigate. Flying laboratory
The C-130J is a military
transport plane adapted
for weather research.
Robots in the sky
Packed with scientific
NASA uses unpiloted drone
instruments, each
aircraft to study the formation
plane has four powerful
and intensity of hurricanes.
turboprop engines,
Drones can stay airborne for
which can keep it flying
twice as long as a
for up to 14 hours as it
C-130J plane can.
tracks hurricanes.
