Climate


Know the difference between weather and climate.

Weather: the weather is the temperature and precipitation occurring now. Weather changes from day to day and even from hour to hour.

Climate: the climate of an area is the average temperature and precipitation ranges over a long period of time. Climate data is usually collected for 30 years to determine an area's climate.

There are four things that affect the temperature of a climate:

Latitude:

Latitude lines go from 0 degrees to 90 degrees both north and south. Latitude shows how far you are from the equator. Climates are colder as you move away from the equator. Latitude lines split the globe into six major climate regions. These climate zones are on your climate zone graphic organizer in your notes. Be sure to know all teh information on the outside adn inside of this graphic orgainzer!


Direct and Indirect light: The reason that latitude affects temperature is that it shows what areas of the Earth receive direct light and which receive indirect light.

Tropics: this area is the warmest because at some point inthe tropics the sun's light is hitting the earth at a 90 degree angle. This is direct light and it is intense (very warm!).

Temperate: In these regions the sun's light hits at an angle less than 90 degrees and more than 45 degrees. The light is indirect, but still intense enough to be hot in summer. These areas have 4 seasons.

Polar: these areas recieve very indirect light at an angle less than 45 degrees. This makes these regions very cold all year. Because of the extreme cold they actually receive very little precipitation.

Elevation:

This one is easy! It is colder the higher you go and warmer at lower elevations. The why is more difficult. Many people have the misconception that it will be warmer up high because you are closer to the sun. Our very highest mountains are only about 5 miles up. the sun is an average of 93,000,000 miles away. Those extra few miles are insignificant!!

Students should also understand that the sun does not heat the air. It heats the Earth which then gives off heat tot he air. There are fewer surfaces to heat as you go up. Also their are less molecules at higher elevations (the air is thinner) so there is less air to hold the heat.

Nearness to a Body of Water:

Coastal vs. Intercontinental

This one is tricky! Most people want to be able to say being near water makes a place warmer. Or they want to say being near water makes it colder. But neither are correct.

Coastal
Being near a large body of water, like an ocean, makes a moderate climate. That means it does not get too hot or too cold. The water stores heat all summer which it gives off during the winter making the winter not too cold. It looses heat all winter cooling down meaning in the summer it is cooler and helps cool the area making the summer not too hot.

This happens because water does not heat or cool quickly (Remember our land vs water experiment?). It takes months for a large body of water to change its temperature. SanFrancisco is a good example of a climate like this (You have a graph of this!)

Intercontinental
You need to know that intercontinental means a city or region in the middle of a continent away from the coast. (On your graph that was the city of St. Louis).

As we saw in our experiment land heat and cools very quickly. Land does not take months to gain or lose heat like an ocean does. It takes hours, sometimes minutes! Think how quickly the black top heats up each day, and how quickly it cools when the sun goes down.

Areas without water to moderate their temperature are extreme climates. They have very hot summers and very cold winters.

Wind and Ocean Currents: