Sunny
Cloudy
Rainy
Dry
Muggy
100
What is the basic cause of all weather and why
The sun is the basic cause of all weather.
The sun’s heat causes the water molecules to enter the atmosphere through evaporation.
Once the water vapor is in the air and that air begins to move, this creates all kinds of weather.
100
What is Evaporation?
Evaporation - The process of a liquid turning into a gas
100
Explain Dry vs. Muggy
Since you live in the South, you are well acquainted with muggy air. That feeling that all of the water vapor in the air is thick and heavy.
In a desert, the reverse is true. The air is dry almost completely absent of water vapor.
100
what is Humidity and what does the level depend on?
Humidity is the amount of water vapor in the air. The maximum amount of water vapor that air can hold depends on the temperature of the air. The limit decreases as the temperature decreases. So warm air can hold more water vapor than cold air can.
100
What does saturated mean in regards to humidity?.
When the air is holding its full limit of water vapor, the air is saturated.
200
give an example of how humidity works
Example: Let’s say that the temperature of the air in the rain forest falls at night, while at the same time the amount of water vapor in the air remains the same. During the day the air was 93% full of water vapor. But now as the air cools, the amount of water vapor that it can hold steadily decreases. Soon it hold 94% of the maximum amount, the 95%, and so on.
200
What is relative humidity and how is it expressed?
We usually express the humidity of the air as a percentage. This percentage measures the relative humidity of the air. It is the humidity relative to saturated air. It tells us only how full of water vapor the air is ------ NOT how much vapor the air contains.
200
What is the dew point, and explain what happens when the temperature falls. .
The temperature at which cooling air becomes saturated is called the dew point.
The lower the temperature falls, the more water would be “squeezed” out of the air .
The dew point is the lowest temperature at which the air can keep all of its water vapor. If air cools beyond the dew point, some of its water vapor changes into liquid water during the process of condensation.
200
explain this weather proverb:
When the dew is on the grass,
Rain will never come to pass.
With dew on the grass it usually means the sky is clear. During the day, the clear skies will continue and thus it will be a sunny day with no rain.
200
When grass is dry at morning light,
Look for rain before the night.
explain this proverb
Cloudy, windy nights are warmer with no dew, and clouds and wind can foretell rain
300
what is condensation and when does it occur in regards to weather?
The dew point is the lowest temperature at which the air can keep all of its water vapor. If air cools beyond the dew point, some of its water vapor changes into liquid water during the process of condensation.
300
what conditions are needed for dew to form on the ground?
Two conditions needed for dew to form on the ground:
Clear skies
Little (or no) wind
Clouds help to absorb and reradiate heat energy back to the surface which keeps the ground temperature from falling as far as it does on clear nights when the earth’s radiant energy can escape more easily into space.
Brisk winds constantly stir up the air so that no group of air molecules stays in contact with the ground long enough to form a layer of cold air just above the ground.
300
what is frost. explain
Frost is NOT frozen dew. If it were, it would look like tiny balls of ice. Instead is looks white and feathery.
Frost is a solid that was never a liquid. When the ground cools below the freezing point of water, water vapor cannot condense into a liquid. Instead it bypasses the liquid phase and turns directly into a solid on the ground called frost.
300
Explain the 5 steps to how a cloud is made
Water evaporates into the air, producing a mixture of air and water vapor.
The air-vapor mixture must be heated by the earth. Remember, this heating does not happen evenly: a mass of surface air may grow warmer than the air surrounding it.
Cooler, denser air will wedge under the warmer, less dense air and push it upward, along with its load of water vapor.
The rising air will cool until, upon entering the cold upper regions of the troposphere, it reaches its dew point, the lowest temperature at which it can hold all of its water vapor.
If the air cool further, some of its vapor must condense. A CLOUD IS BORN!
300
How does water vapor turn into a liquid in mid air?
here is dust in the air. The water vapor will condense onto the dust particles and now there are tiny water droplets. The tiny dust particle that allows condensation is called a condensation nucleus.
The billions of water droplets formed in this way are so small and light that they stay suspended high in the air, forming white, fluffy clouds.
400
Explain what a thermal is and what it affects
It’s a hot day on the football field. The area around the field is wooded with lots of shade. The field is going to heat faster than the shaded area around it. As the day move on, the air on the field will begin to rise up as the cooler denser air from the wooded area comes rushing in. The rising air goes up like a column of warm air called a thermal. The warm air rises, cools, may reach its dew point and will begin to condense onto condensation nuclei. This will be a white puffy cloud on a blue sky.
Thermals: Ordinarily, a column of warm air rising from a hot spot on the earth’s surface will continue to grow upward as long as the air at the top of the column remains warmer (and therefore less dense) than the surrounding air. So, small clouds form on days when weather conditions prevent thermals from rising very high, but larger clouds develop on days when thermals are free to soar to higher levels.
400
What is a thunderhead? how and when and why is it created?
Unstable Air: When rising thermals cool more slowly than the lapse (cooling) rate of the surrounding air, the atmosphere is said to be unstable. Unstable days are marked by the growth of tall clouds that seem to grow taller and taller. If the day is especially hot and humid, conditions are ideal for the formation of giant “super clouds” called thunderheads.
400
what is temperature inversion, and what type clouds does it involve?
he initial warmth of the air near the surface, along with the tremendous quantities of water vapor it contains, allows for the development of very powerful thermals that push air upward at dozens of miles per hour.
As the thermals continue to surge upward, it draws in more and more hot air and water vapor from ground level, which adds fuel to the fire. All of the condensation that results from the rising and cooling of these large amounts of warm, moist air produces a gigantic cloud that may stretch upward all the way to the tropopause. When this rising air, hits the “lid” at the temperature inversion, they quit rising upward and begin to spread out over a wide area, giving the cloud a broad, flat top.
400
Explain what is meant by Stable Air and when does it occur?
On cooler days, the rising thermals cool more rapidly than the lapse rate of the surrounding air. When this happens, the growth of the thermal is very limited. It will not rise very high because it does not remain warmer than the surrounding air for very long. In this case, the air is stable.
Stable days create very little or no clouds.
400
explain what is meant by Unstable air and when does it occur?
Unstable Air: When rising thermals cool more slowly than the lapse (cooling) rate of the surrounding air, the atmosphere is said to be unstable. Unstable days are marked by the growth of tall clouds that seem to grow taller and taller. If the day is especially hot and humid, conditions are ideal for the formation of giant “super clouds” called thunderheads.
500
Explain Mountain clouds. Draw a diagram of how they form.
Mountain Clouds: The Rocky Mountains of N. America, the Andes Mountains of S. America, and the Ural Mountains of Central Asia all lie right in the path of prevailing winds. When the wind collides with a mountain range, it has no choice but to flow over it. The rising air cools, the temperature of the air drops below the dew point, water vapor condenses, and clouds begin to form. Mountain clouds have distinctively smooth flowing shapes which reveal the pattern of the air flow over the mountaintop.
500
how are most clouds formed?
Most clouds form when a surface wind meets an obstruction that pushes it upward. When the rising air cools below its dew point, water vapor condenses and produces clouds.
500
Explain how mountain clouds make their own weather on each side of the mountain.
what are the 2 sides of the mountain called?
Mountains Make Their Own Weather:
On the windward side of the mountain, where the air is flowing uphill, cloudiness and rain will likely prevail which means lush vegetation.
On the leeward side, where the air is flowing downhill, the land might be dry with only stunted plants.
500
explain what Frontal Clouds are and how that are created
The third process that gives birth to clouds is the head-on collision between cold air and warm air at a weather front.
Weather front - the boundary between a warm air mass and a cold air mass. The cold air is denser, it pushes the warm air upward. The rising warm air cools, resulting in condensation and the formation of clouds.
500
Draw a diagram of Frontal Clouds developing
