Weather for Kids By: Abhilash V. and Jesh Kim

The Earth’s atmosphere is the layer of gases that surrounds the planet. It is composed of oxygen, nitrogen, carbon dioxide, water vapor and many other gases. The atmosphere is made up of 4 layers just like a cake; the troposphere, the stratosphere, the mesosphere and the thermosphere. The atmosphere is home to weather and where it actually develops and begins. A lot of heat transfer in the atmosphere makes this happen. All three types of heat transfer (radiation by sun's rays , convection through liquids and conduction through solids by contact) occur in the atmosphere, but the most common of them is convection. Convection in the atmosphere occurs when the air near the ground gets hot, this causes molecules to gain energy and move faster. This causes them to bump into each other and move farther apart which in turn causes the air to become less dense and this warm air rises over the cooler and denser air causing convection in the atmosphere.

Atmosphere

The Atmosphere consists of four layers as I said before which are the troposphere, stratosphere, mesosphere and the troposphere. The troposphere is the closest layer to the earth and is where weather forms, it has a height of 10 km (0-10 km). The next closest layer to the earth is the stratosphere which contains the ozone layer that protects us humans from ultraviolet light which is dangerous to humans, this layer stretches 15 km high (10-25 km). The next closest layer to the earth is the mesosphere which stretches 75 km high (25-100 km). The last layer and the farthest layer from the earth is the thermosphere, this is the layer in which meteorites burn up and where the Northern Lights occur. This layer stretches 300 km (100-400 km).

Layers of the Atmosphere

Convection is the movement of the molecules traveling through liquids. Convection can not happen in solids because of bulk and diffusion. Convection is one of the major heat transfers. Convection means a transfer of heat from one place by means of fluids. When the air near the ground gets heated, the molecules move faster which makes them bump into each other. That causes them to move farther apart which makes the more dense and this warm air rises over the cooler and denser air causing convection in the atmosphere.

Convection

It is a large scale for the wind patterns of the atmosphere.Wind pattern/currents are named after which way they blow from. Some of the wind patterns Doldrums,Trade wind,Prevailing Westerlies,Polar easterlies, and of course there are way more.

Wind currents

Doldrums are located near the equator which is an imaginary line that cuts the earth in half. It receives the most sun's heat. The wind is calm and weak. Weather in the doldrum are hot,humid and rainy.

Doldrums

Trade winds are located a little bit above the Doldrums (30 degrees). These winds are created by surface high pressure areas in subtropics replacing rising air in the doldrum. They are calm, have a few clouds, little rainfall,warm air rises from the equator then cools and sink.

Trade winds

Prevailing Westerlies are strong winds that are located near the trade winds or higher(30-60 degrees). The wind can come from any direction but mostly comes from the west to east.because of high pressure areas(anticyclones), and low pressure areas(cyclones).

Prevailing Westerlies

Polar easterlies are cold,dry,weak prevailing winds. They are located near the north and south pole(50-60). They blow from the east to west.

Polar Easterlies

It is when objects move in rotating places.

http://www.youtube.com/watch?v=aeY9tY9vKgs

Coriolis Effect

Local Winds are short winds that can blow from any direction. It is caused by unequal heating of the earth's surface in a small area. They only form when no winds are blowing from far away.

Local Winds

Sea breezes are winds that blow from the sea to land. Also known as on shore winds. The land heats faster than the sea so the land air is heating earlier than the sea air. The hot air expands and creates a low pressure area.

Sea Breeze

Land breezes are winds that blow from land to sea. They are also known as offshores. The land cools faster than the water so the land air gets colder than the sea air temperature.

Land Breeze

It is a temperature that changes frequently occur near the equator. It is usually warm air near the equator. It appears about every 2-5 years.

El Nino

La Nina is a wind that is opposite of El Nino. It is usually cool air that is located near the equator. It occurs every 2-5 years.

La Nina

About 10 kilometers above the earth's surface that has high speed winds are called jet streams. These winds are very wide but not that deep. Jet streams travel from west to east traveling about 200-400 kilometers. They wander from north to south in wavy directions.

Jet Stream

There are two types of ocean currents; one is surface currents and the other is deep ocean currents or density currents. Surface currents make up 10% of all the water in the ocean and density currents make up 90% of the water and are denser because of temparature and the amount of salt in the water which causes the colder currents to go under the warmer currents. These density currents form when the colder water goes underneath the warmer currents and they move like a conveyor belt, cold water sent to the ocean from melting ice caps goes down while the warmer currents come up and the process repeats itself again. Surface currents are the waves that move through the ocean at the surface, these currents are driven by wind on the surface that helps the water on the surface to move.

Ocean Currents

High pressure areas are also known as anticyclones. It is formed when the atmospheric pressure is greater than the surrounding environment. They turn clockwise in the northern hemisphere and in the southern hemisphere counterclockwise. This is because of the Coriolis effect.

High Pressure

Low Pressure occurs in area of depression or low elevation like a valley. These systems form because of winds that move apart in the upper troposphere and cause bad weather like tropical storms and hurricanes. Precipitation like snow and rain, bad weather and warm and high winds come with low pressure area.

Low Pressure

There are 3 types of fronts;warm front, cold front and stationary front.

Fronts

It is when the surface air goes out and the cool air goes in.

Warm Front

Cold pressure is when surface winds come in and warm air rises and then clouds form. It can cause cloudy skies,low levels of sunshine,wet weather,mild temperature,windy condition, and changeable weather.

Cold Front

This is when both cold and warm air masses meet but stay still.

Stationary Fronts

Hurricanes are severe tropical storms that form in warm waters that are moist. The moisture start rising and evaporating making moist and heated winds that start spinning towards the left or counterclockwise. As these winds get intense, they form a severe tropical storm with very high wind speeds. The eye or center of a hurricane is relatively peaceful compared to the 70-200 miles per hours winds surrounding the eye. These storms can have very serious and bad effects and this is why scientists track them with radar/satellite images and warn the public before the storm gets close.

Hurricanes

They are a column of air that contacts with the earths surface. It spins rapidly destroying the earth's surface. they are also known as twisters. For a tornado to form you need warm moist, and cool dry air. When they meet they create a tornado.

Tornados

The Sun is the closest star to the Earth and is about 93 million miles away. The Sun is what provides the Earth with its source of sunlight during the day. The Sun's energy reaches the Earth in the form of electromagnetic waves or heat made by rays from the sun and heats all the objects. This form of heat transfer in known as radiation in which the sun transfers heat to objects through electromagnetic waves. Sun's energy reaches the earth in the form of visible light, infrared radiation and ultraviolet radiation. Visible light is made when all the colors of the rainbow mix together (the light seen everyday). Infrared radiation is longer that red, but can only be felt as heat (not seen). Ultraviolet radiation is shorter that purple light and can cause major damage to humans us a sunburns and skin cancers (the color seen when looking at the sunset out of a tinted window).

Sun and Sun's Energy

Isotherms are lines on maps that connect areas of equal temparature. They give meteorologists and the general public and overview of the temperatures across a big of land such as a country. Meteorologists use isotherms to keep track of temperature in certain areas which can be used to predict temperatures in areas to warn people of extremely cold or hot temperatures. They also help when predicting low/high temperatures. Isobars are lines on a map that connect areas of equal air pressure. They are used to find broad areas of the same air pressure such as a country. When isobars are close together, it indicates windy conditions and when they are far apart, it indicates areas of sunny and fair weather. Isobars are used by meteorologists to find the pressure of certain areas and use it to identify the weather conditions in that area.

Isotherm and Isobar

Precipitation is when condensed liquid fall from the sky in different forms. The types of precipitation are rain,snow,snow pellet,snow grain,ice crystal,sleet/ice pellets,hail,graupel,drizzle,freezing drizzle,freezing rain,freezing fog, and mixed precipitation.

Types of precipitation

Rain is when water droplets fall from the sky and hit the earths surface. There are different categories of rain,light,moderate and heavy.

Rain

Snow is like rain but like ice crystals. It is basically rain but in frozen form. It freezes when the temperature of the area having rain is cold enough to make the rain freeze.

Snow

Snow grains are exactly what they seem like. They are just grains of snow. When comparing them to drizzle they are solid.

Snow grain

Ice crystals are also called diamond dust. They are ice crystals that float in the wind.

Ice crystal

It forms by ice crystals and supercooled water. Soft hail is less dense and white which has air bubbles.

Hail

Graupel is also called soft hail, and snow pellets. they are formed when supercooled water droplets freeze on a snowflake making a ball of rime.

Graupel

Drizzle is light little rain. The are smaller than rain. They are less than 0.5 millimeters across. Drizzle are formed by stratiform, and stratocumolus clouds.

Drizzle

There are a various number of clouds that exist, but the most common of all the clouds are Stratus, Altostratus, Altocumulus, Cirrostratus, Cirrocumulus, Cirrus, Cumulonimbus and Cumulus clouds.Stratus clouds are grayish and low clouds that look like fog that does not touch the ground. Stratus clouds may drizzle sometimes, but do not precipitate. These clouds are obscured by fog, but when fog lifts it results in low stratus clouds.

Types of Clouds:Stratus

These clouds are dark, grey and wet looking clouds that cause continuous snowfall and precipitation. These clouds produce a little bit of precipitation.

Types of Clouds:Nimbostratus

The next type is known as Altostratus, these clouds stay at a middle level in the sky and look blue or blue gray. These clouds are formed out of water droplets and ice crystals. The clouds form before storms and bring nonstop precipitation for a long time. These clouds cover the whole sky and sometimes a round disk can be barely seen in the sky.

Types of Clouds: Altostratus

Altocumulus can be found in the middle of the sky and are made up of water droplets. They look like puffy, little parallel bands that fill up the sky. These clouds are made in hot and humid weather such as a day in summer and they show that a thunderstorm will happen in a few hours.

Types of Clouds:Altocumulus

Cirrus clouds are wispy and thin clouds found high in the sky. They are stretched to look like long streamers because of the high winds. They move across the sky from west to east and usually bring good or fair weather.

Types of Clouds:Cirrus

Cirrostratus clouds are sheetlike and thin clouds that cover the sky. They do not bring bad weather and are so thin that the moon is visible from above the clouds.

Types of Clouds:Cirrostratus

These types of clouds have a flat bottom that is just about 1000 meters above the ground and have puffy towers that stretch up very high. These clouds look like fluffy pieces of cotton floating in the sky. These clouds grow vertically and can become cumulonimbus or thunderstorm clouds.

Types of Clouds:Cumulus

Cirrocumulus clouds are found high in the sky and look like small white puffs that cover the sky. They are referred to as a mackerel sky because the clouds look like a fish's scales.

Types of Clouds:Cirrocumulus

These type of clouds form when cumulus grows big enough to become thunderstorm clouds. The top of these clouds extend up to 39,000 feet of the base and these clouds hover over the ground. The condensation of water vapor in these clouds release huge amounts and tornadoes, lightning and thunder are associated with these clouds.

Types of Clouds:Cumulonimbus

Dew point is the temperature where the air can't hold the water vapors. Dew,fog, or clouds can form. Condensed water can be called as dew when formed on a solid surface.

Dew Point

Scientists get images of weather such as fronts, systems or any storms from satellites. These satellites in space take images from above the earth of a whole country or certain area that show forming storms and other important weather. These images are then sent to scientists who use them to predict any weather patterns and understand storms better before they hits.

Science Images

Thermometer- A thermometer is a weather instrument that measures the air temperature of where it is located.Barometer- It is a tool that measures the air pressure.Wind vane- It is a tool where it tells you which direction the wind is blowing from.Anemometer-Measures wind speed.

Meteorologist Instrument

Weather Balloon-It measures whether higher in the atmosphere.Rain Gauge- Measures the amount of rain that have fallen on a specific amount of time.Hygrometer- Measures the water vapor content of air or the humidity.

Meteorologist Instruments

Abhilash Jesh

● Atmosphere Convection● Ocean Currents Wind Currents● Low Pressure High Pressure● Hurricanes Fronts● Sun and Sun's Energy Tornadoes● Isotherm and Isobar Types of Precipitation● Types of Clouds Dew Point● How scientists get images Meteorological Instruments ● Graphics used by scientists Weather Map