What does a raindrop look like as it is falling? A B C

What does a raindrop look like as it is falling? A B C

As the raindrop falls, it bumps into air molecules, flattening out the bottom of the drop! Force or air resistance Force of gravity

Water can be in the form of a Solid, Liquid or Gas; It all depends on how much energy it has.

When water is in its solid state (ice), the water molecules are packed close together preventing it from changing shape. Ice has a very regular pattern connected by bonds that form a crystalline lattice. These crystals have a number of open regions and pockets making ice less dense than liquid water. This is why ice floats on water. Ice forms when the temperature is below freezing (0 Celsius or 32 Fahrenheit).

When ice is warmed above freezing, it melts and becomes liquid water. As a liquid, the attractive forces between molecules weaken and individual molecules can begin to move around each other. Because the molecules can slip and slide around one another, water takes the shape of any container it is in.

The third state of water is the gaseous state (water vapor). In this state, water molecules move very rapidly and are not bound together. Although we cannot see water in its gaseous state, we can feel it in the air on a hot, humid day. Commonly, water boils at a temperature of 100 C or 212 F, forming water vapor.

NOT HERE! OR HERE! Many people believe that the visible plume of steam from a boiling kettle is water vapor. However, the steam that you see consists of very small water droplets suspended in the air, while water vapor is the invisible gas that results when water evaporates. We can only "see" water vapor through the electromagnetic eyes of infrared-sensing instruments.

The spout people see is actually caused by exhaled air. Since he exhaled air is typically warmer than the surrounding air, it ools rapidly as it flows out. The water vapor in the air mmediately condenses into a liquid, giving the appearance of praying water.

So, if we can see it, water is either liquid or solid!

Contrails form high in the atmosphere when the mixture of water vapor in the aircraft exhaust and the air condenses and freezes. Persisting contrails can spread into extensive cirrus clouds that tend to warm the Earth, because they reflect less sunlight than the amount of heat they trap. The balance between Earth's incoming sunlight and outgoing heat drives climate change.

CLOUDS CAUSED BY AIRCRAFT EXHAUST MAY WARM THE U.S. CLIMATE NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994.

Classification of Clouds: Stratus clouds are a uniform gray and usually cover most of the sky. Cirrus clouds Cumulus clouds

Stratus clouds Cirrus clouds are thin and high in the sky. Cumulus clouds

Con Trails

Stratus clouds Cirrus clouds Cumulus clouds are lumpy and can stretch high into the sky.

Low-level clouds: (generally found below 6,500 feet) Low-level clouds are usually composed of liquid water droplets, but they can have snow and ice crystals in cold weather. Mid-level clouds: (generally found between 6,500 and 23,000 feet) Most mid-level clouds are composed of liquid water droplets during summer and a liquid droplet-ice crystal mix during winter. Mid-level cloud names are preceded by an "alto" prefix. High-level clouds: (generally found above 20,000 feet) High-level clouds are composed of ice crystals and tend to be very thin and wispy. Highlevel cloud names are preceded by a "cirro" prefix.

Assignment: On your model of the troposphere, fill in 10 clouds (include their names, what their names mean, and what type of water they contain) at the appropriate elevation. Add one specialty cloud from pages 151-155 in the Meteorological text (no one else in your group may have the same type). Explain why the moisture in all clouds doesn t just immediately fall to the ground, in which case we wouldn t every have any clouds.

Day 2: Clouds

Low Clouds- Fog liquid water Advection fog forms when humid air flows over cold ground or water. Radiation fog forms on generally clear, cool nights. Steam fog forms over water, often in the fall.

Low Clouds liquid water Stratus clouds are uniform grayish clouds that often cover the entire sky. They resemble fog that does not reach the ground. Usually no precipitation falls. Nimbostratus clouds form a dark gray, "wet" looking cloudy layer associated with continuously falling rain or snow.

2 more Low Clouds liquid water Cumulus clouds are puffy clouds that sometimes look like pieces of floating cotton. The base of each cloud is often flat and may be only 330 ft above the ground. The top of the cloud has rounded towers. These clouds grow upward and form a thunderstorm cloud. Stratocumulus clouds are low clouds with irregular masses that are rolling or puffy in appearance.

Mid level or "Alto" Clouds 6500 to 23,000 ft. Altocumulus clouds are made of water droplets and appear as gray, puffy masses, sometimes rolled out in parallel waves or bands. The appearance of these clouds on a warm, humid summer morning often means thunderstorms may occur by late afternoon. Altostratus clouds are gray or bluegray composed of ice crystals and water droplets. These clouds usually cover the entire sky. In the thinner areas of the cloud, the sun may be dimly visible as a round disk. Altostratus clouds often form ahead of storms that will produce continuous precipitation.

High Clouds made of ice crystals 20,000 ft + Cirrus clouds are thin, wispy clouds blown by high winds into long streamers. Cirrus clouds usually move across the sky from west to east. They generally mean fair to pleasant weather. Cirrostratus clouds are thin, sheet like high clouds that often cover the entire sky. They are so thin that the sun and moon can be seen through them. Cirrocumulus clouds appear as small, rounded white puffs. The small ripples in the cirrocumulus sometimes resemble the scales of a fish. A sky with cirrocumulus clouds is sometimes referred to as a "mackerel sky."

Multi-level Clouds Cumulonimbus clouds are thunderstorm clouds that form if cumulus clouds continue to grow vertically. Their dark bases may be no more than 1000 ft above the Earth's surface. Their tops may extend upward to over 39,000 ft. Tremendous amounts of energy are released by the condensation of water vapor within a cumulonimbus. Lightning, thunder, and even violent tornadoes are associated with the cumulonimbus.

White Clouds: small water droplets that scatter all light (so you see white).

Grey or Black Clouds: BIG droplets that absorb most light. White Clouds: small water droplets that scatter all light (so you see white).

Grey or Black Clouds: BIG droplets that absorb most light. White Clouds: small water droplets that scatter all light (so you see white). Grey or Purple Clouds: old clouds whose smaller droplets have evaporated over time.