Transcript Guided Notes on Gathering Weather Data

Guided Notes on
Gathering Weather Data
Chapter 12, Section 3
1.
Meteorologists measure the
atmospheric variables of
temperature, air pressure,
wind, and relative humidity in
order to make accurate weather
forecasts.
2. Two of the most important
factors in weather forecasting
are the accuracy and the
density of the data, which
refers to the amount of data
available.
3. Barometers measure air
pressure using mercury.
Changes in air pressure are
indicated by changes in the
height of a column of mercury.
4. An anemometer is used to
measure wind speed and a
hygrometer measures
relative humidity.
5. The National Weather Service
in the U.S. has established a
surface observation network
across the country, which
gathers data in a consistent
manner at regular intervals.
What does a ceilometer measure and
estimate?
 It
measures the height of cloud
layers and estimates the amount
of sky covered by clouds
7. The weather that we
experience is largely the result
of changes that take place high
in the troposphere.
Meteorologists must gather
atmospheric data at heights of
up to 30,000 m.
8. A radiosonde is a balloon-borne
package of sensors that is used to
gather upper-level data. These
sensors measure temperature, air
pressure, and humidity and are
sent by radio signal to a ground
station that tracks the movements
of the radiosonde.
9. Electromagnetic waves in a
weather radar system are
programmed to bounce off large
raindrops. The radar system
rotates in a circle, allowing
meteorologists to gauge where rain
is falling within the radar’s range.
10.Because the motion of moving
raindrops is caused by wind,
Doppler radar provides a good
estimation of the wind speeds
associated with precipitation areas,
especially those experiencing
thunderstorms and tornados.
11.Cameras mounted aboard a
weather satellite take photos of
Earth at regular intervals. Satellites
track clouds, but not necessarily
precipitation. Scientists combine
data from radar and satellites to
determine where both clouds and
precipitation are occurring.
12.Some satellites use infrared
imagery to detect differences in
thermal energy, which are used
to map cloud cover or surface
temperatures.
13. Infrared images allow
meteorologists to determine the
temperature of a cloud, from which
they can infer its type and its
height. This is especially useful in
detecting strong thunderstorms
that extend to great heights in the
atmosphere.
14. Because the strength of a
thunderstorm is related to its
height, infrared imagery can be
used to establish a storm’s
potential to produce severe
weather.