7. Atmospheric Stability and Cloud Formation.

Atmospheric Stability and Cloud Formation

By Jason King

SUMMER SCHOOL

Multiple Choice

What Is Dew point

• that xbox is better that the nintendo switch

• How big fortnite's community is

• the temperature to which air must be cooled to become saturated with water vapor.

• how humid the air can be

Multiple Choice

The temperature at which air is saturated with water vapor and condensation occurs is called

• humidity
• air pressure
• dew point
• relative humidity

Multiple Choice

Which type of air holds more water 

• warm 
• cold 

Multiple Choice

The temperature to which air must be cooled in order to become saturated is the: 

• Relative Humidity
• Mixing Ratio
• Dew Point Temperature
• Wet-bulb Temperature

Multiple Choice

What kind of air describes "humid" air? 

• warm and wet 
• cold and dry
• cold and wet
• warm and dry

STABILITY

Tendency of air to remain in its original position (stable) or to rise(unstable)

Heat energy absorbed and release

When water changes state, heat is exchanged between water and its surroundings. When water evaporates, heat is absorbed. When water condenses, heat is released.

This heat is measured by calories. One calorie is the amount of heat required to raise the temperature of 1 gram of water 1C.

Adiabatic temperature changes

When air is allowed to expand, it cools. When air is compressed, it warms. Temperature changes produced in this manner, in which heat is neither added nor subtracted, are called adiabatic temperature changes.

Dry Adiabatic Rate

The rate of cooling or warming of vertically moving unsaturated ("dry") air is 10°C for every 1000 meters (5.5°F per 1000 feet), the dry adiabatic rate

Condensation level

At the lifting condensation level (the altitude where the parcel of air has reached saturation and cloud formation begins), latent heat is released and the rate of cooling is reduced.

wet adiabatic rate

The slower rate of cooling, called the wet adiabatic rate of cooling ("wet" because the air is saturated) varies from 5°C per 1000 meters for air with a high moisture content to 9°C per 1000 meters for air with a low moisture content.

Cloud Formation

When air rises, it expands and cools adiabatically. If air is lifted sufficiently high, it will eventually cool to its dew-point temperature, and clouds will develop. Condensation occurs when water vapor is cooled enough to change to a liquid

Lifting Condensation Level

The altitude at which a parcel reaches saturation and cloud formation begins is called the lifting condensation level (LCL). Level of Clouds.

Four mechanisms that cause air to rise

Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain

Four mechanisms that cause air to rise

frontal wedging, where warmer, less dense air is forced over cooler, denser air along a front

Four mechanisms that cause air to rise

Convergence is an atmospheric condition that exists when there is a horizontal net inflow of air into a region. When air converges along the earth's surface, it is forced to rise since it cannot go downward. Large scale convergence can lift a layer of air hundreds of kilometers across

Four mechanisms that cause air to rise

localized convective lifting, where unequal surface heating causes localized pockets of air to rise because of their buoyancy

The three fundamental conditions of the atmosphere

Absolute Stability, when the environmental lapse rate is less than the wet adiabatic rate

The three fundamental conditions of the atmosphere

Absolute Instability(UNSTABLE), when the environmental lapse rate is greater than the dry adiabatic rate

The three fundamental conditions of the atmosphere

Conditional Instability(UNSTABLE), when moist air has an environmental lapse rate between the dry and wet adiabatic rates.

Multiple Choice

This image shows energy being transferred in a system. Where does energy transfer to an air parcel from?

• The sun's energy transfers directly to an air parcel.

• The sun's energy transfers to the surface then the surface transfers energy to the air parcel.

• An air parcel creates it's own energy.

• Air parcels do not change temperature which means energy is never transferred.

Multiple Choice

In an adiabatic process there is no _________ transfer between the gas and the surroundings.

• Kinetic Energy

• Work

• Thermal Energy

Multiple Choice

Day 1 and Day 2 in Greenville started with the same amount of water vapor in the air parcels there. It rained at the end of Day 2 but it did not rain at the end of Day 1. What could have happened to the air parcel to cause rainfall on Day 2?

• The air parcel was warmer than the surrounding air, so it lost energy.

• The air parcel was warmer than the surrounding air, so it gained energy.

• The air parcel was at the same low temperature as the surrounding air, so it had low energy.

• The air parcel was cooler than the surrounding air, so it gained energy.

Multiple Choice

The temperature at which water vapor condenses is the 

• relative humidity
• humidity
• freezing point
• dew point

Multiple Choice

Heat that is "hidden" and does not produce a temperature change.

• Evaporation
• Condensation
• Latent Heat
• Humidity

Multiple Choice

When water goes from a solid state to a gas without going through the liquid state we call this....

• sublimation
• deposition
• condensation
• evaporation

Multiple Choice

When water vapor changes to a liquid state we call this .....

• evaporation
• condensation
• sublimation
• deposition

Multiple Choice

When liquid is changed to a gas we call this....

• condensation
• sublimation
• evaporation
• deposition

Multiple Choice

When water vapor goes from a gas to a solid. Ex) frost on a window

• sublimation
• deposition
• evaporation
• condensation

Multiple Choice

when air is lifted because mountains act as barriers we call this

• orographic lifting
• frontal wedging
• convergence
• localized convective lifting

Multiple Choice

when air is lifted because a warm and cold air mass meet and the warm less dense air is lifted over the cool air

• orographic lifting
• frontal wedging
• convergence
• localized convective lifting

Multiple Choice

When thermals are created due to the unequal heating of the Earth we call this...

• orographic lifting
• frontal wedging
• convergence
• localized convective lifting

Multiple Choice

The rate of cooling or heating (10⁰F for every 1000 m) that only applies to unsaturated air is called the

• Wet Adiabatic Rate

• Dry Adiabatic Rate

• Atmospheric Lapse Rate

• Temperature-pressure Causal Rate

Multiple Choice

The slower rate of heating or cooling (5⁰C for every 1000 m) because of the condensation of saturated air is called the:

• Wet Adiabatic Rate

• Dry Adiabatic Rate

• Atmospheric Lapse Rate

• Temperature-pressure Causal Rate

Multiple Choice

Occurs when horizontal air flow is pushed up vertically.

• Orographic Lifting

• Frontal Wedging

• Convergence

• Localized Convective Lifting

Multiple Choice

Occurs when warmer, less dense air is forced over cooler, denser air.

• Orographic Lifting

• Frontal Wedging

• Convergence

• Localized Convective Lifting

Multiple Choice

Why are some of the rainiest places in the world located on the windward side of mountains?

• As air is forced upslope, the temperature of the air drops below the dew point and causes precipitation

• When air hits a mountain its movement slows, allowing water to fall

• The higher altitude means lower temperatures and more snow. Most of that snow melts into rain.

• Most windward mountains are located near oceans, which means more rain

Multiple Choice

Why does unstable air form more clouds and precipitation than stable air?

• Unstable air rises and cools to the point where condensation occurs and rain forms

• Unstable air contains more water vapor than stable air so it is more likely to form clouds and rain

• Unstable air resists movement, so it sits longer over an area and has more of a chance to form clouds and rain

• Unstable air is usually sinking as it cools, which increases the chances of forming clouds and rain