5th Period, Katie, Jordan, Hayden: All About Weather

All About Weather

By Katie Langford, Jordan Scott, and Hayden Lowrance

Atmosphere The atmosphere is the layer of gases which surround the Earth. Like a blanket, the atmosphere protects the earth and traps energy from the sun. It makes conditions on earth suitable for living things.

Nitrogen, oxygen, carbon dioxide, water vapor, and other gases make up the atmosphere.

This picture shows the different layers of the atmosphere.

Wind Wind is air moving sideways from different spaces of air.

Winds are caused by the differences in the pressure of air.

The movements of the wind from different pressures is called Wind Currents. The wind currents are always happening. It brings the cool breeze that cools you down when you are playing outside. It can also make the air around you feel colder. Brrr!

When it feels really cold because of the wind, it is called wind chill. Wind chill is the measurement of how cold it feels.

Ocean Ocean currents are movement of water due to winds, tides, or density. Ocean currents affect the weather and temperature in a few ways. One way is that whenever the surface water of the ocean is warmer, the air above it has more water vapor in it. Clouds form when the surface water is warm and the air pressure decreases. When the air pressure decreases, the water vapor cools to form water droplets, which cling to dust/smoke particles in the air. Tons of water droplets and dust come together and form a cloud. Another way is that land near water does not heat up or cool down as fast as land that is not near water, so temperatures of land near water will be lower than land that is isolated.

Pressure Have you ever had trouble breathing in cold air? When there is high pressure, the air is all bunched up together. It makes it feel hard to breath because there are so many pieces of air in the little space that you are trying to breath.

Those wind currents are caused because of differences in air pressure.

The air pressure can either be high or low. High pressure is normally colder air, while low pressure is normally hotter.

Air pressure is the measure of how much air there is in your area. If the air pressure is low, then there is not as much air in your area.

Have you ever seen one of these? It is an air pressure gauge. It is used to measure the amount of air in an amount of space. People use it on the tires.

When the needle is low then it means that the air pressure is also very low.

Fronts A front is where two air masses with different densities meet. There are four types of fronts: warm, cold, occluded, and stationary.

Warm front: when a warm air mass and a cold air mass meet and the cold air goes underneath the warm air because it is denser. When the warm front is humid, it rains or snows where the air masses meet, but if the warm front is dry, scattered clouds form. The weather will usually be humid after a warm front though.

Cold front: when a warm air mass and a cold air mass collide and the cold air sinks underneath the warm air because it is more dense, but the cold air pushes the warm air up. Then, the warm air rises and reaches its dew point and forms clouds. Whenever there is a lot of water in the warm air, it rains or snows, but when there is very little water, there are cloudy skies. Since the cold front moves fast, it causes sudden weather like thunderstorms. Cool fronts bring dry air, clear skies, and cold temperatures. c o l d f r o n

w a r m f r o n t

Fronts Occluded front: when a warm air mass gets stuck between two cold air masses, the cold air masses move beneath the warm air and push the warm air up. the cold air masses mix and the temperature near the ground cools. Warm air cannot get to the ground so the warm air cools, water vapor condenses, and clouds form.

Stationary front: a warm and a cold air mass collide but don't move each other and have a "standoff". Rain, snow, or fog comes and it stays like that for a few days if the two air masses remain stationary.

Occluded front

Stationary front

Hurricanes Hurricanes are a big and horrible storm. When you experience a hurricane, you will see lots of rain and wind. The rain or any other thing that falls from the sky can also be called precipitation! Hurricanes can be up to 600 miles wide!

That's huge! This giant storm can leave a trail of destruction behind it. Over the course of a week, the storm can wreck many buildings and towns along the coast. The strong winds that can be as fast as 200 miles per hour combined with the flooding rain destroys many unlucky towns.

In the hurricane there is an "eye". The eye is a central location that the storm revolves around. This is the one point that isn't covered up by clouds.

Tornadoes A tornado is a funnel of wind moving in a spiral motion that comes out of a storm cloud and touches the surface. They come out of cumulinimbus clouds, low and heavy clouds, and usually come with a thunderstorm. Wind speeds can get up to 480 km per hour and nearly 800 tornadoes occur in the U.S. every year. Tornadoes are short storms, but also one of the deadliest and most damaging. They usually occur in the spring and summer because the ground is warm. They can occur anywhere when it is warm, but they are known to form in the Great Plains and Tornado Alley because it's where a cold and a warm air mass meet and the cold air goes underneath the warm air, but then rises. A squall line is formed and tornadoes frequently form at that squall line.

Waterspouts are tornadoes that form over a body of water like a lake or an ocean.

Energy From the Sun Almost all of Earth's energy comes from the sun. It travels to the earth as electromagnetic waves. Energy reaches the earth in visible light, infrared radiation, and ultraviolet radiation. The atmosphere absorbs and reflects a part of this energy.

Some energy is absorbed by the surface, heating the land and water.

When the surface is heated it radiates some of the energy back into the atmosphere as infrared radiation. This energy heats water vapor and gases in the atmosphere causing the greenhouse effect. As a blanket traps heat radiating from your body, the atmosphere traps heat radiating from the Earth, causing both to stay warm.

Weather Map

Isotherm and Isobar Isotherms are mainly used on weather maps in newspapers. They show areas of equal temperature. Meteorologists, scientists who study the Earth's atmosphere and weather, use these to separate areas of different temperatures.

Isobars are also used on weather maps. They show areas of equal pressure.

Meteorologists use these to separate areas of different pressure. Areas labeled with an "L" are low pressure areas and areas labeled with an "H" are areas of high pressure. When the lines get closer together, the area will receive windy conditions. Large areas of low pressure are called troughs and large areas of high pressure are called ridges.

Precipitation When water vapor condenses it forms ice crystal or water droplets. When clouds become heavy, the water droplet or ice crystal fall down to the earth in different forms of precipitation.

Rain:This is the most common form of precipitation. It occurs when water droplet fall to the earth, in showers or drizzle. A shower is made of large, heavy drops, and lasts for a short time. A drizzle is made of smaller, finer drops, and and lasts for a long time.

Snow: When water vapor condenses directly to ice, by condensing around an ice crystal, snow is formed. Snow falls to the earth as snowflakes.

Sleet: Snow and rain, along with raindrops that freeze as they fall, form sleet.

Hail: Ice crystals form in cumulonimbus clouds, then begin to fall toward the earth. As they fall, the wind picks them up and pushes them back into the cloud where they grow larger in size. They fall again, and the process repeats itself until the hail is too heavy for the wind to carry.

Clouds Clouds form when water vapor in the air condenses into water droplets or ice crystals. Water droplets are made of water vapor, dust, and smoke. There are four types of clouds. Cumulus clouds are puffy and white with flat bottoms, and look like cotton balls. Stratus clouds are low and in layers, like fog. Cirrus clouds are made of ice crystals, featherlike and bright white.

Cirrus

Stratus

Cumulus

Dew Point What is dew point? Well, dew point is the temperature that condensation begins. Whenever the freezing point is higher than the dew point, then the water vapor in the air instantly turns into crystals of ice. These ice crystals all cling to dust particles and come together to form a cloud.So whenever the dew point is above freezing point, then the air around is just very humid.

This picture shows dew on grass like on mornings.

How Scientists Get Images Scientists can get images from many of the satellites looking down on earth from space. These satellite images allow the scientists to see what is happening in the atmosphere. Scientists can see when a big hurricane will arrive by looking at satellite images. They can easily see where it is. It gives them a new way to look at the weather.

This is one of the many satellites that scientists use to get the satellite images.

Meteorological Instruments Here are a few tools that scientists use. ● ● ● ● ● ● ● ●

Thermometer- This is used to determine how hot it is.

Barometer- This is used to find the air pressure.

Rain Gauge- This is used to find how much rain has fallen.

Wind Vane- This is used to show the direction that wind is blowing.

Anemometer- This is used to measure wind speed.

Weather Maps- This is used to display the predicted weather.

Weather Balloon- This is used to measure weather farther up in the atmosphere.

Weather Satellites- This is used to see the weather from space.

Jobs Katie

Hayden

Jordan

Atmosphere

Pressure

Isotherm and Isobar

Energy From the Sun

Hurricanes

Ocean

Precipitation

Wind

Tornadoes

Clouds

Meteorological instruments

Dew Point

Weather Map

How Scientists Get Images

Fronts