Warm up Page: 583, 1. Weather observation are based on a variety
of measurements including: atmospheric __________,
_______, _____________, wind speed and precipitation.
• Pressure, humidity, temp.
Page: 583, 2. Most thermometers use one of two liquids
which are ________ or _________
• Mercury or alcohol
Page: 584. 3. What does the instrument called a
barometer measure?
Air pressure
Objective: S.W.B.A.T.
• Identify various weather instruments and explain
what aspect of weather each measures
• Explain the units each weather instrument uses
• Complete by reading questions on weather
instruments
Activities: • Warm-ups
• Notes/discussion
• Worksheet on weather instruments
Weather Weather Instruments
Chap 21, sec. 3
Meteorologist need data from a variety of
sources (tools and instruments) that help
predict weather.
Air Temperature Thermometer – use to measure air temp., made with a glass tube with either mercury(silver) or alcohol (red or green)
H20 =
Fahrenheit = 32˚ freezing
212˚ boiling
Celsius = 0˚ freezing
100˚ boiling
Air Moisture (humidity) Relative humidity – amount of water vapor in the air
compared to the greatest amount it can hold.
Measured in % (percent)
100% humidity air can not hold any more water vapor
(saturated)
The temperature at which air can become saturated
(and condenses) is called (dew point)
Psychrometer & Sling psychrometer – instrument that
uses two thermometers (wet & dry bulbs) comparing
the difference between each, one can calculate
relative humidity
Psychrometer
Hygrometer – uses hair or chemical plastic strip, the
hair or plastic curls up (contracts) when high humidity
and expands when low humidity – which is attached
to a scale.
Air Pressure
Mercury barometer – is a long tube closed at one end and filled with mercury, at the open end the weight of the air pushes down measuring pressure on a scale – most accurate type.
Air pressure
Aneroid barometer – a mechanical spring inside expands and contracts due to pressure changes Pressure is measured in millibars or inches of mercury (sea level = 1,013 mb) High pressure – clear cool fair weather Low pressure – bad or stormy weather
Wind Vane – measures wind direction - * a wind
vane points to the direction wind is coming
from. Winds are named for the direction they
come from.
Wind direction and speed
Wind Direction = Wind Vane
a Wind Sock
Anemometer – measures wind speed
- in m.p.h., km/hr., or knots
- 1 knot = 1.85km/hr. or 1.15 mph
Precipitation
Rain Gauge – measures the amount of precipitation falling to Earth. Measured in inches or centimeters
- To measure snow use a ruler 1 inch of rain = 10 inch of snow
RAIN GAUGE
Electronic
Rain Gauge
Cloud cover Local cloud cover you use your own visual observation and cloud chart and estimate percent of sky covered (nephoscope)
Nephoscope Instrument used to measure direction, speed, and percent of cloud cover in a given area
Other weather instruments
Radiosonde – a package of instruments attached to a radio transmitter, which is connected to a weather balloon to gather data in troposphere and stratosphere
• Radiosonde
Balloon
Parachute
Radiosonde
A Radiosonde measures
• Temperature,
• Air pressure,
• Wind Speed and Direction,
• Humidity in the upper atmosphere.
• Chemistry of gases like amount of ozone or percent of CO2
Radar • - “radio detection and ranging” Used to
find rain or snow within clouds. Doppler radar gives motion of precipitation in storm path
Satellites - give meteorologist pictures over a wide area used in forecasting and tracking weather
Computers – stores and records data and plots information on maps (computer models) for use by meteorologist in forecasting
Weather maps – gives the total data of an areas weather to help and predict new weather.
Cool down 1. What does an anemometer measure?
Wind speed
2. What is freezing and boiling on the Fahrenheit
scale?
212 degrees
