Transcript Weather & Climate

Weather
Water Cycle: the continuous
movement of water between the
atmosphere, the land, and the
oceans
 Evaporation occurs when solar
energy heats water molecules,
and they rise as gaseous water
vapor.
 transpiration: the process by
which plants release water
vapor into the air through
their leaves
 precipitation: any form of
water that falls to Earth’s
surface from the clouds
Weather
 Air Pressure
 The barometric pressure, also
called atmospheric pressure
or air pressure, is the pressure
that results from the weight
of a column of air extending
from the top of the
thermosphere to the point of
measurement.
 Changes in barometric
pressure often accompany
changes in the weather.
Weather
〉Differences in air
pressure cause air to
move creating winds.
 pressure gradient: a
difference in air pressure
from one place to another
 The air in a pressure
gradient moves from areas
of high pressure to areas of
low pressure.
 wind: the movement of air
from a high-pressure area
to a low-pressure area
Weather
 Coriolis effect: the curving
of the path of a moving object
from an otherwise straight
path due to Earth’s rotation
 Points at different latitudes
on Earth’s surface move at
different speeds.

Earth goes through a full
rotation in 24 hours.

Points on the equator travel the
Earth’s full circumference in 24
hours.

Points closer to the poles do
not travel as far.
Weather
 Predictable air circulation
forms wind patterns.
 Winds in the Northern
Hemisphere curve clockwise.
 Winds in the Southern
Hemisphere curve
counterclockwise.
 The resulting patterns are
very regular, and have been
named by meteorologists.
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Polar easterlies
Westerlies
Northeast trade winds
Southeast trade winds