climate

Climatevs.

Weather

The short term condition of the

atmosphere

The average weather in an

area over a long period of time

Both are defined by:temperaturehumidity winds precipitation

I. What Determines

Climate?4 factors

A. Latitudedistance from equator measured in degrees north or south of the equator

equator: 0° latitude

North Pole: 90° N

South Pole: 90° S

A. Latitude

Equator = direct, concentrated sunlight

Poles = less sunlight because of the angle of the earth’s tilt.

A. Latitude

Effects of Latitude on Solar Angle

B. Atmospheric Circulation

Patterns

3 important properties of air: Cold air sinks,

and warms as it sinks.

Warm air rises and cools as it rises.

3 important properties of air:

Warm air holds more water vapor than cold air.As warm air cools, the water vapor it

contains condenses forming rain, snow, or fog.

3 important properties of air:

1. Wind is a result of cooler air replacing warm air that rises

B. Atmospheric Circulation Patterns

2. Because different latitudes get different amounts of solar energy…

B. Atmospheric Circulation Patterns

…we get different winds & different circulation patterns of precipitation.

B. Atmospheric Circulation Patterns

Why does the equator get such large amounts of

rainfall?

Why does the equator get such large amounts of

rainfall?

Answer:Answer:Warm air holds lots of

water that evaporates from oceans & land. As air rises, it cools & loses ability to hold lots of water. Thus, it rains heavily at the equator.

C. Ocean Circulation Patterns

C. Ocean Circulation Patterns

1. caused by winds & rotation of earth

2. make climates more moderate

coasts have warmer winters & cooler summers than inland

C. Ocean Circulation Patterns

D. Local Geography

D. Local Geography

1. Higher elevations are cooler

2. mountains cause air to be deflected upwards & cooled…

D. Local Geography

…so it releases moisture on one side of mountain but not on other.

D. Local Geography

III. Seasonal Changes in

Climate

Seasons are caused by

Earth’s 23.5° tilt

SEPTEMBER AND MARCH 22

JUNE 21

DECEMBER 21

EARTH IS TILTED

A TILTED EARTH WOULD EXPLAIN MOST OF THE OBSERVATIONS THAT WE SEE .

THE EARTH IS TILTED AT A 23.5 DEGREE ANGLE.

Solar AngleBeam spreading reduces intensity of solar energy

Atmospheric Beam Depletion

Earth-Sun Relations

Earth’s Seasons

Mythbuster

Tell this to everyone you know:

“Earth’s seasons are solely a result of the tilt of earth’s axis, and NOT due to how close or far from the sun our planet is!!!

bibliography

Slides 25 through 35 are used with permission (as per the millennium copyright act) from the following website:

raider.muc.edu/~mancuscm/lecture%20ppts/Lecture%201.ppt midwoodscience.org/mcdonnell/seasons.ppt