Transcript Introduction to Weather

Introduction to Weather
Ms. Cervera
Bellringer # 1
Windsurfers harness the power of the wind to
skim their boards across the water.
Windsurfers pay attention to many weather
factors, not just the wind. They might choose to
stay off the water during cold or rainy weather
or when a storm is on its way.
 Describe at least three weather factors that
you observe in this image.
Today’s Learning Objectives
Students will be able to…
 Identify and describe the different variables used to
describe weather
 Explain the relationship between air pressure and the
density of air
What is Weather?
 Weather is the atmospheric conditions, along with
short-term changes, of a certain place at a certain
time.
 Temperature and rainfall are just two of the
variables used to describe weather.
 Meteorologists use a variety of variables to predict
weather, including air temperature, air pressure,
wind speed and direction, humidity, cloud
coverage, and precipitation.
Weather Variables: Temperature
 Air temperature is the measure
of the average kinetic energy of molecules in the air.
 Molecules in warm air move faster than molecules in
cold air.
 Temperature is measured in degrees.
 The temperature scale used by scientists is the
Celsius scale.
Weather Variables: Air Pressure
Weather Variables: Air Pressure
 Air pressure is the pressure that a column of air
exerts on the air, or surface, below it.
 The air pressure at any particular point on the Earth
depends on the density of the air.
 Air pressure is measured with an instrument called a
barometer.
 As air moves from areas of high pressure to areas of
low pressure, it creates wind.
Winds
 Warm air has a lower density than cool
air.
 Warm air rises and produces an area of
low pressure, while cold air produces an
area of high pressure
 As air moves from areas of high pressure
to areas of low pressure, it creates wind.
 Meteorologists measure wind speed
using an instrument called an
anemometer.