Earth Processes Part 3: Atmosphere (weather) Weather #1

The parts that make up the universe: Atmosphere- consists of the “air”…gases. Hydrosphere- consists of the “water” Lithosphere- consists of the “land” Biosphere Includes all three!!! All organisms are found w/in the biosphere.

Lithosphere

Hydrosphere

Atmosphere

What is Air? It’s Got Us Covered Air is made up of matter- it takes up space. Air is a mixture of gases- tiny fast moving particles in motion. Air is made up of nitrogen, oxygen, carbon dioxide, & water vapor.

Composition of the Atmosphere

Weather Weather- The condition of the atmosphere at a certain place and time. When talking about weather, you are actually describing what is happening in the atmosphere. Weather is constantly changing. Without the atmosphere, there would be no weather!

Feeling the Air Dark colored materials heat up quicker than light colored materials. So air above dark colored surfaces heats up quicker. When air is warmed the particles spread out. Warm air becomes lighter & rises. The cooler air sinks. This movement of air is called WIND.

Wind is represented by this symbol. It is called a wind barb. The barbs point in the direction from which the wind is blowing FROM.

The more “tails” there are on the barb… the stronger the wind.

The circle attached to the wind barb tells you the “cloud cover”.

The top left number represents the temperature in degrees Fahrenheit.

The number in the bottom left corner represents the dew point. Dew points represent the amount of moisture in the air.

The thing dividing the temperature and the dew point is called the “weather symbol”. In this case…there is fog.

The number in the right corner represents sea level pressure. We will not get into this.

Land & Sea Breezes Land Breeze (cool land/warm sea) Cool air over land moves out toward the water and takes the place of rising air. Warm air over the water rises. Sea Breeze (warm land/cool sea) Warm air over the land rises. Cool air over the water moves toward land and takes the place of the warmer air that has risen.

Weather terms you need to know… Humidity - measure of the amount of water vapor (moisture) in the air. Dew point - When air is cooled to the temperature at which it can hold no more water vapor, it comes together and “dew” (water droplets) form.

Evaporation - water changing into gas…going into atmosphere. Precipitation - moisture coming down from the atmosphere. Rain, snow, hail, sleet (frozen rain). Evaporation - water changing into gas…going into atmosphere. Condensation - gas changing into water. (dew) all three of these terms are involved in water cycle

Barometric pressure- measure of the pressure caused by Earth’s gravitational force pulling on the column of air above you. High pressure (H) - fair weather, sunshine Low pressure (L) - gray, cloudy skies and sometimes precipitation

Clouds How do they form?? Water vapor in the air reaches its dew point and condenses into water droplets. Clouds are classified/named by their HEIGHT & SHAPE Height will come 1st and shape 2nd!!! Clouds can give us clues of upcoming weather.

Types of Clouds 3 main shapes: Cirrus Stratus Cumulus Based on height & shape… Height will come 1st and shape 2nd!!! Cirrostratus Cirrocumulus Altostratus Altocumulus Nimbostratus Stratocumulus Cumulonimbus

SHAPE: Flat clouds = Stratus (St) Fluffy clouds = Cumulus (Cu) Wispy clouds = Cirrus (Ci)

HEIGHT: Cirro- Highest clouds Alto- Middle level clouds Strato- Lowest clouds (usually just name of cloud with out a prefix)

Nimbus, nimbo = Dark and rainy

Cumulonimbus = thunderstorm cloud that takes up all levels…type of cloud to form tornadoes.

What are fronts. A front is where TWO air masses meet What are fronts? A front is where TWO air masses meet. Changes in weather take place along a front. Cold Front Leading edge of colder air that is replacing warmer air. Warm Front Leading edge of warmer air that is replacing cooler air.

Occluded Front When a cold front catches up to a warm front Occluded Front When a cold front catches up to a warm front. Moving together. Stationary Front A front that is NOT moving!

http://ww2010.atmos.uiuc.edu/%28Gh%29// guides mtr/af/frnts/cfrnt/prcp.rxml

http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/af/frnts/wfrnt/prcp.rxml

Weather maps have many things going on. Reading weather maps… Weather maps have many things going on. You need to know and be familiar with all the symbols.

A thunderstorm is a storm with lightning AND thunder, produced by a cumulonimbus cloud, usually producing gusty winds, heavy rain and sometimes hail.

Thunderstorm Development Thunderstorms develop in warm, moist air ahead of eastward-moving cold fronts. Require strong updrafts and downdrafts. (vertical winds) Weather systems (storms) move west to east!

Fun Facts about Thunderstorms: The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Nearly 1,800 thunderstorms are happening at any moment around the world. Every thunderstorm produces lightning, (but you can’t always see it or it doesn’t touch down). It kills more people each year than tornadoes. You can estimate how many miles away a storm is by counting the number of seconds between the flash of lightning and the clap of thunder. Divide the number of seconds by five to get the distance in miles.

MYTH: If it is not raining, then there is no danger from lightning MYTH: If it is not raining, then there is no danger from lightning. FACT: Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall. MYTH: The rubber soles of shoes or rubber tires on a car will protect you from being struck by lightning. FACT: Rubber-soled shoes and rubber tires provide NO protection from lightning. However, the steel frame of a hard-topped vehicle provides increased protection if you are not touching metal. Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside. MYTH: "Heat lightning" occurs after very hot summer days and poses no threat. FACT: What is referred to as "heat lightning" is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction!

Lightning!!!!! The attraction of opposite charges (static electricity).

When lightning strikes (touches the ground)… When lightning strikes (touches the ground)….actually half came down from the bottom of cloud (stepped leader) and half came up from the ground (streamers). Two opposite electrical charges are attracted and meet halfway…once they are connected….charges flow!!!

What is Thunder??? The sound that results from a flash of lightning and is caused by sudden expansion of the air in the path of the electrical discharge. Lightning always produces thunder. They actually happen at the SAME time. Light and sound move at different speeds. Light travels faster than sound.

DOPPLER RADAR - helps detects thunderstorms

Thunderstorm lingo: single cell - normal, one storm multicell clusters - many single cell storms squall lines- a line of storms together (multicell) supercell - severe thunderstorms with strong winds that spin and spiral….can develop into a tornado!!!! Also can produce large hail.

Tornadoes!!!!! Tornadoes are produced inside powerful thunderstorms, which in turn are created near the junction between warm/moist air and cold/dry air. The greatest activity occurs in April, May, and June (Spring/Summer), but no month is free of them. The most favorable areas for tornado activity include Texas, Kansas, Oklahoma, and Missouri. “Tornado Alley” - most tornadoes occur (Texas up to S. Dakota)

Tornadoes that touch down on water are called waterSPOUTS. Strong tornadoes can form from a “wall cloud” Watch - before the weather develops…the conditions are right. Warning - the weather condition is occurring or has occurred close to your area…take precautions.

Remember that storms have UNSTABLE air produced by different temperatures and updrafts & downdrafts (lifts).

What does pressure do to the space a gas takes up? BEHAVIOR OF THE AIR/GASES Boyle’s Law Robert Boyle investigated the relationship between the volume of a gas and its pressure. What does pressure do to the space a gas takes up? More pressure - smaller gas space Less pressure - bigger gas space BEHAVIOR OF THE AIR/GASES Boyle’s Law Robert Boyle investigated the relationship between the volume of a gas and its pressure. What does pressure do to the space a gas takes up? More pressure - smaller gas space Less pressure - bigger gas space

More pressure = less volume (smaller gas space) Less pressure = more volume (larger gas space)

Charles’s Law Jacques Charles investigated the relationship between the volume of a gas and temperature. He noted that the volume of a gas increased with the temperature. Temperature increase = increase volume, gas particles move faster (expand/rise) Temperature decrease = decrease volume, gas particles slow down (sinks)