Transcript Welcome back students

Welcome to Class
What is radiation and how does it affect Earth?
Agenda
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Conduction and Convection Notes
Lab
Seasons Notes
Movie
Radiation
• Energy from the sun
• Other ways heat transfers in Earth’s system
• Convection and Conduction
Conduction
• conduction – transfer of energy through direct
contact
• Heats the lowest few centimeters of the atmosphere
Convection
• convection - movement of matter due to
differences in density caused by temperature
variations
• Cold air sinks and warm air rises
• Convection occurs when gases or liquids are
heated unevenly
Convection Cont.
• Cold air is more dense than hot air
– pressure is lower beneath warm air
• Dense, cool air moves into a low-pressure
region, less dense, warmer air is pushed up
• Creates convection cells and wind
Gets displaced and
moves over
AIR
AIR
Cools and
sinks
AIR
Gets displaced &
moves over
AIR
Gets heated
and rises
Explain the Terms
• Turn to someone
and explain
conduction
• Turn to another
person and explain
convection
Demos
• I have some demos set up
• I want you to go around and answer the
questions on the handout
SEASONS
Movie
What Causes the Seasons?
• NOT how close we are
• Earth is tilted at 23.5 degrees
• The tilt of Earth is away in the winter but towards
the sun in the summer
• Direct vs. Indirect
Cause of the Seasons
• Same amount of sun hits a larger area in the
Northern and Southern latitudes
– Less intense sun hits higher and lower latitudes
than at the equator
Seasons at the Equator
• The equator really has no seasons
• The sun’s intensity is equal year round
• The sun shines direct and covers a smaller
area than in the North and South
Key Terms
• Solstice – when the sun is the highest in the
sky (the longest days of the year)
• Equinox – equal amounts of light and dark
More Terms
• Solar Eclipse – moon passes between the Sun
and the Earth
– Sun is fully or partially obscured
• Lunar Eclipse – Moon passes through some
portion of the Earth's shadow
– Earth in the middle