WEATHER AND CLIMATE

CHAPTER 2 SECTION 1

WHAT IS WEATHER?

• Weather- Conditions in one place over a short period of time.

• Climate- Conditions in one place over a long period of time.

THE GREENHOUSE EFFECT

• The Earth’s atmosphere traps some of the heat from the sun and reflects it back to Earth much like the glass ceiling of a green house.

ROTATION VS. REVOLUTION

• Rotation – The spinning of the earth around it’s Axis.

• Revolution – The movement of the earth around the sun.

SOLSTICES VS. EQUINOX

• Solstice – June 21 and December 21. The days when the sun appears directly above the tropics of Cancer and Capricorn. Summer and winter.

• Equinox – March 21 and September 23. When the sun is directly over the equator. Vernal (spring) and Autumnal (fall).

DISTRIBUTING THE SUN’S HEAT

• The heat of the sun is distributed through convection.

• Warm gases rise and cooler gases fall.

• In the air, this process is called wind.

• In the water, this process is called currents.

• Due to the rotation of the earth, circular patterns are created called the Coriolis Effect.

TYPES OF PRECIPITATION

• Precipitation – Water that falls from earth’s atmosphere (Rain)

• Convectional Precipitation

• Occurs in warm climates

• Produces lots of rain which helps to feed lush, tropical rainforests.

TYPES OF PRECIPITATION

• Orographic Precipitation

• Warm, moist air is forced upwards over high landforms.

• As warm ocean air meets mountains, it is forced into cooler air where it condenses and rain or snow falls.

• The Air is usually dry and cool by the time it reaches the other side of the mountains creating deserts.

TYPES OF PRECIPITATION

• Frontal Precipitation

• Occurs when two fronts meet.

• The warm air is forced upward by the dense cool air.

• The rising warm air cools and frontal precipitation forms.

OTHER INFLUENCES ON CLIMATE

• Nearby bodies of water

• Have milder climates since water doesn’t change temperature as much as land does

• Continental Climates – Inland areas that have more extreme temperature changes between hot and cold.

• U.S., China, Central Europe and Northern Eurasia.

• Minnesota can reach -20⁰ F in the Winter and over 100⁰ F in the summer

OTHER INFLUENCES ON CLIMATE

• Elevation

• Higher elevation has colder temperatures. That is why there is often snow on the top of mountains.

OTHER INFLUENCES ON CLIMATE

• Nearby Landforms

• Mountains, forests, and even cities can affect the temperature and climate of nearby areas.

WORLD CLIMATE REGIONS

• The Earth can be broken up into 5 types of climate regions.

• Tropical

• Dry

• Moderate

• Continental

• Polar

CHANGING CLIMATES

• Through changes in nature and human action, the worlds climates are changing.

• Many scientists call this change “Global Warming”

• The earth has cycles of climate change

• Ice Age

• Warming

• Earth’s temperature is rising

• This creates more extreme weather as the earth tries to balance this out.

• We are overdue for another ice age.