1. Activity 51 – What is Weather and Why does it matter?
Weather Recording

2. Copy the Data Table in Your Notebooks(HW)
Unit Of Measure
Day 1
Mon.
Day 2
Tue.
Day 3
Wed.
Day 4
Thurs.
Day 5
Friday
Temp.
Precipitation
Inches
Air Pressure
Decimal/%
Cloud Cover
Wind Direction
N,E,S,W
Wind Speed
MPH
Pressure System
High or Low
Weather Front
Cold, Warm, Stationary
Copy the Data Table in Your Notebooks(HW)

3. Recall what you did each of the five days that you recorded the weather. What aspect of the daily weather affected your daily life?
Imagine that you are a meteorologist, how would summarize the weather for the last five days?
Looking at the average weather for the month of November in 2007, do you think that our weather is relatively the same or has it changed this year in the same month?
Which type of weather data, daily or monthly, more useful for describing the weather. Explain your reasoning.
Reflection of weather

4. Quick Notes
Weather

5. The Atmosphere Air- is a mixture of gases
Atmosphere- is a layer of gas that surrounds the Earth
Atmosphere supports and protects life
Without the atmosphere the Earth would be a giant rock
Atmosphere is very thin, similar to the fuzz on a peach
The Atmosphere

6. Layers of the Atmosphere
Troposphere:
Layer closest to Earth
Layer is heated by the ground, so temperature decreases as you move up
Contains storms and airplanes
80% of Earths atmosphere
Stratosphere:
Contains the ozone; ozone absorbs the UV Radiation from the sun
Layer heats up as you move up due to the absorption of suns energy
Layers of the Atmosphere

7. Layers Continued… Mesosphere:
This layer is heated from the stratosphere so it cools as you move upward
Contains Meteors; the meteors burn up as they enter this layer
Less than 1% atmosphere mass
Thermosphere:
Farthest from Earth
Suns radiation heats this layer, causing it to rise in heat as you move upward
There is little density; causing it to feel colder then it is because everything is spread out
Becomes Outer space, Satellites orbit here, Space shuttles would fly here
Layers Continued…

8. Create a diagram to represent the 4 main layers of the atmosphere, how they surround Earth and 1 fact about each layer
In your notebook

9. Air Pressure is the force of molecules pushing on an area, air pressure moves in all directions
Air Pressure Related to Altitude and Density:
Air pressure is determined by the weight (mass) of the air above it
As you move up in the atmosphere you are also moving up in altitude, this upward movement has less weight (mass) so there is less air pressure; less air pressure, density and mass in Flagstaff.
If air pressure was the same in all places air would not move; air pressure is always moving from areas of high pressure to areas of low pressure.
Much like opening a can of tennis balls or soda, there is little pressure inside, but the high pressure on the outside rushes inward.
Barometers are instruments that measure the amount of air pressure. It is a flexible machine that expands and contracts with the change in pressure
Air Exerts Pressure

10. Moving Air - Uneven heating of Earth’s surface causes air to move; wind
Weather is the condition of Earths Atmosphere at a particular time and place.
Wind is air that moves horizontally or parallel to the ground
Much like air pressure, wind moves from areas of high pressure to low pressure
Formation of Wind:
First, low pressure, or warm air, rises
Second, high pressure, or cold air, sinks
Winds then move across the surface of Earth
This can be such a slight change that you may not even feel the movement of the wind or air
Some winds die after a short distance.
Movement of Air

11. Global winds: travel long distances and may last weeks
Global winds: travel long distances and may last weeks. Uneven heating between the poles and the equator cause the winds Coriolis Effect: Curves the winds from the poles as the Earth rotates
Types of Wind

12. Monsoons Monsoons are winds that change directions with the seasons
Caused by different heating and cooling rates
Flow long distances and effect large areas
Winter Monsoons occur when land is colder then the sea
Summer Monsoons occur when land is much hotter then sea
Monsoons

13. Temperature Affects Water in the Air
Water is always in the atmosphere
When temperatures change water changes form
Evaporation is changing from a liquid to a gas and condensation is a gas changing into a liquid
Gas in this process is water vapor
Precipitation is any liquid that falls to Earths surface
Humidity is the amount of water in the air
Saturation of the air means that the amount of water evaporating is equal to the amount of water that is condensing
Temperature Affects Water in the Air

14. Formation of Clouds Clouds form when water vapor condenses
Warm air rises and cools as it gets higher, the cooling of the air forms ices crystals or water droplets, these droplets form the clouds
The water must condense on to something hard, such as the dust particles that are in the air. Smoke, and salt are other examples
Fog: A cloud that rests on the ground or a body of water. Has a smooth appearance. Forms when the ground is colder then the air around it
Formation of Clouds

15. Clouds Cirrus: Curl of Hair, form in high altitudes
Made of ice crystals, feathery appearance.
Winds form the tails of these clouds, these tails show the direction of the wind in the upper troposphere. Seen in fair weather, but can indicate that a storm is approaching
Clouds

16. Clouds Continued Cumulus: Heap or Pile often like cotton balls.
Puffy white clouds, with dark bases.
Form in the day time when warm air rises and the vapor condenses. If they keep growing they produce showers.
Smaller ones only produce light showers that last less then an hour, larger ones that reach 18kilometers (11miles) will produce large thunderstorms
Stratus:
Spread-out, flat layers, appear gray.
Are smooth clouds because there is little wind when forming the clouds.
If they are low they can produce light and steady precipitation as well as block the sun and moon. When higher in the atmosphere they are thinner and produce a halo of light around the sun and moon.
Clouds Continued

17. http://www.phschool.com/atschool/phsciexp/active _art/weather_fronts/
Chapter Three Notes

18. Large volume of air in which temperature and humidity are the same in different areas but not at the same altitude
Takes on the same characteristics as the area it is in. If it is cold then the mass is cold, if it is wet the mass becomes moist and so on.
Air masses

19. Warm Fronts: -Move Slowly
Warm Fronts: -Move Slowly. -Warm air moves over dense cold air, -High cirrus and stratus clouds. -Hours of rain or snow fall Stationary Fronts: -The cold and warm fronts and don’t move. It may remain this way for a few days, and cause clouds coverage. Eventually it will become one of the other fronts.
Fronts: A boundary between air masses There are three types of fronts Cold Fronts: -Move Quickly. -Cold air push against warm air, causing the warm air to rise. -Cumulus clouds -Heavy storms -After the storm weather is clear and cool
Fronts

20. Pressure Systems and Weather
High Pressure:
Large
Air is sinking and moving clockwise
Clear Skies, calm air, gentle breeze
Low Pressure:
Air circles counter-clockwise and moves upward
Air moves faster as it moves up, this can cause stormy weather

21. Formation of Storms Low Pressure Systems Can Become Storms:
-Tropical storms are low pressure storms that form near the equator. Winds of 65 kph
-Hurricane low pressure storms with winds of 120kph. Can uproot trees.
Formation and Effects Of Hurricanes:
-Strike between August and October
-It grows over warm water, Dies out when water gets cold or moves over land
-Eye of the storm is clear, Just around the eye are large cumulus clouds
-Cause tornadoes, heavy rains, damage, flooding, storm surges (huge walls of water)
-There is time to plan and evacuate

22. Winter Weather Winter Storms:
- Winter storms happen when two storms collide
- Can be warned 48 hours prior to a storm
Blizzards:
- Blinding snow storm with winds of 56kph and low temperatures. Can knock down trees and power lines, pipes can freeze, facilities may be closed
Ice Storms
Freezing rain
Covers everything with heavy and smooth ice
Hard to drive, things break with the weight of the ice, can shut down entire cities

23. Chapter review
Chapter 3.1 Answer questions 3, 4, 5 and 6. Create diagrams that represents a cold front, warm front and low pressure system. Briefly label them with the type of weather they produce. Chapter 3.2 Answer questions 1, 3, and 5 Chapter 3.3 Answer questions 1, 2, 3, 4, and 5