Earth ScienceEarth Science

March 23rd, 2011

Mrs. Harris

ObjectivesObjectives

Describe characteristics of Earth’s atmosphere. Describe the processes of radiation, conduction,

and convection. Differentiate between various types of winds.

WindWind

Created by differences in air pressures. Flows from areas of high pressure to areas of

low pressure.

How does air have different pressures?

Why does heat rise? Because heat is not matter, it isn’t correct to say it rises or falls.  A better

way to ask the question is: "Why do hot things (like hot air) rise above cold things (like cold air)?" To answer this question, it is important to understand what heat is.

Why does heat rise? Because heat is not matter, it isn’t correct to say it rises or falls.  A better

way to ask the question is: "Why do hot things (like hot air) rise above cold things (like cold air)?" To answer this question, it is important to understand what heat is.

Heat is energy.  When we say something is hot, we really are saying it has a lot of stored energy. What does this energy do?

Why does heat rise? Because heat is not matter, it isn’t correct to say it rises or falls.  A better

way to ask the question is: "Why do hot things (like hot air) rise above cold things (like cold air)?" To answer this question, it is important to understand what heat is.

Heat is energy.  When we say something is hot, we really are saying it has a lot of stored energy. What does this energy do?

Matter is made up of incredibly small pieces called atoms and molecules.  Atoms and molecules are always moving. The more energy these atoms and molecules have, the faster they move.  The faster they mover, the more space they take up.

Why does heat rise? Because heat is not matter, it isn’t correct to say it rises or falls.  A better

way to ask the question is: "Why do hot things (like hot air) rise above cold things (like cold air)?" To answer this question, it is important to understand what heat is.

Heat is energy.  When we say something is hot, we really are saying it has a lot of stored energy. What does this energy do?

Matter is made up of incredibly small pieces called atoms and molecules.  Atoms and molecules are always moving. The more energy these atoms and molecules have, the faster they move.  The faster they mover, the more space they take up.

If something is hot, it weighs the same as if it were cold, but it just takes up more space. This leads us to the concept of density.  Because hat air takes up more space than cold air, hot air has a smaller density. Less dense hot air will "float" above the more dense cold air.

WindWind

Created by differences in air pressures. Flows from areas of high pressure to areas of

low pressure.

Winds that blow mainly from one direction are called prevailing.

Windiest place on Earth? ?

WindWind

Created by differences in air pressures. Flows from areas of high pressure to areas of

low pressure.

Winds that blow mainly from one direction are called prevailing.

Windiest place on Earth? Antarctica

Mark the true statementsWarm air is dense and sinks.

Warm air is less dense and sinks.

Warm air is less dense and rises.

Cool air is denser and rises.

Cool air is denser and sinks.

Cool air is less dense and sinks.

Cool air is less dense and rises.

Wind starts with insolation

Types of windTypes of wind

Trade Wind- prevailing winds that blow from E to W at 30 degrees Latitude in both hemispheres.

Historically, the trade winds have been used by captains of sailing ships to cross the world's oceans for centuries; and enabled European empire expansion into the Americas, and trade routes to become established across the Atlantic and Pacific oceans. (Wikipedia: Trade Winds)

Types of windTypes of wind

Westerlies- are the prevailing winds between 35 and 65 degrees latitude, blowing from the high pressure area in the horse latitudes towards the poles in both hemispheres from west to east.

The Westerlies play an important role in carrying the warm, equatorial waters and winds to the western coasts of continents, especially in the southern hemisphere because of its vast oceanic

expanse. (Wikipedia: Westerlies)

Types of windTypes of wind

Polar Easterlies- dry, cold prevailing winds that blow east to west from the high-pressure areas of the poles highs towards low-pressure areas within the Westerlies at high latitudes in both hemispheres.

Local Wind- movement of air that are influenced by local conditions like temperature. Commonly called Breezes.

Jet Stream- A narrow band of strong winds that blow in the upper atmosphere. Exist in both hemispheres.

winds that blow predominantly from a single general direction over a particular point

Movement of air caused by regional temperatures, called breezesMovement of air caused by regional temperatures, called breezes

Narrow bands of strong wind found in both hemispheresNarrow bands of strong wind found in both hemispheres

This week:

U25 assignment 26-2 quiz 26 discussion 26 test 27-2 quiz

Next class: air masses, storms, and weather forecasting