1.02k likes | 1.66k Views
Weather. The condition of air on earth at any given time or place- whether its warm or cold, dry or wet, blowing or calm. Weather starts with the sun. The sun’s heat warms our atmosphere and causes two things to happen: Water evaporates into the air Air rises.
E N D
Weather The condition of air on earth at any given time or place- whether its warm or cold, dry or wet, blowing or calm. Weather starts with the sun. The sun’s heat warms our atmosphere and causes two things to happen: • Water evaporates into the air • Air rises
Predictable Patterns of Weather continued… Precipitation: depends on the temperatures of the ground and atmosphere. Wind speed and direction: help determine unequal heating or air masses, and is also related to air pressure differences. Temperature: Affected by many factors Cloud Cover: caused by pressure systems and can change precipitation and temperature. Weather Smart: Forecasting and Weather Instruments (United Streaming)
Weather and Climate Facts: • Weather and climate are usually related to: rain, clouds, storms, wind and temperature. • Water is the main factor (water on Earth are constantly interacting, changing and moving) • Clouds also play and very important role when talking about humidity, wind, temperature, geography and precipitation. They can also be linked to specific weather conditions. • Climate patterns: help determine types of weather in different regions.
Review: Water Cycle Evaporation: Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. Condensation: Water vapor in the air gets cold and changes back into liquid, forming clouds. This is called condensation. You can see the same sort of thing at home... pour a glass of cold water on a hot day and watch what happens. Water forms on the outside of the glass. That water didn't somehow leak through the glass! It actually came from the air. Water vapor in the warm air, turns back into liquid when it touches the cold glass. Precipitation: Precipitation occurs when so much water has condensed that the air cannot hold it anymore. The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow. Groundwater/Runoff: When the precipitation falls to the ground and is either soaked into the ground or runs off into rivers, oceans or lakes. Weather Smart: The Water Cycle and Clouds
Water Cycle Songs (Tune of She’ll be Coming Around the Mountain)
(Song to the tune of , It’s Raining, It’s Pouring.) ITS RAINING, ITS POURING THE OCEANS ARE STORING, WATER FROM THE FALLING RAIN WHILE THINDERCLOUDS ARE ROARING THE RAIN NOW IS STOPPING THE RAIN’S NO LONGER DROPPING SUN COMES OUT AND SOAKS UP WATER LIKE A MOP THAT’S MOPPING THE WATER’S STILL THEE NOW BUT HIDDEN IN THE AIR NOW IN THE CLOUDS IT MAKES A HOME UNTIL THIERE’S RAIN TO SHARE NOW
REASONS FOR SEASONS • THE EARTH IS TITLED ON AN AXIS AT THE NORTH AND SOUTH POLE AND THIS CREATES THE SEASONS. • THE IMAGINARY LINE RUNNING THROUGH THE MIDDLE OF THE EARTH IS CALLE D THE EARTH’S AXIS/EQUATOR. • ANOTHER REASON WE HAVE DIFFERENT SEASONS IS BECAUSE THE EARTH MOVES AROUND THE SUN SO THE NORTH POLE IS EITHER FACING TOWARD THE SUN OR AWAY FROM THE SUN. • THE EARTH’S TILT CAUSES DIFFERENT AMOUNT OF SUNLIGHT TO REACH THE EARTH AT DIFFERENT TIMES IN THE YEAR. THE NORTHERN HEMISPHERE GETS MORE DIRECT SUNLIGHT IN THE SUMMER BECAUSE THE SOUTERN HEMSPHERE IS TITLTED AWAY FROM THE SUN THEY ARE HAVING THEIR WINTER. • NEAR THE EQUATOR, THE EARTH DOESN’T HAVE WINTER OR SUMMER. THE WEATHER BARELY CHANGES AT ALL.
REVOLUTION AND ROTATION • REVOLUTION: EARTH MOVING IN A PATH AROUND THE SUN, RESULTING IN ONE EARTH YEAR. • ROTATION: THE EARTH SPINNING AROUND EVERY 24 HOURS, RESULTING IN DAY AND NIGHT.
Weather and Geography There are many geography factors that affect weather and climate. They include: • Latitude • Altitude • Winds • Distance from the sea • Urbanization/living in the city
Latitude: The distance from the equator can determine weather and climate. As you move closer to the equator the temperature increases. The farther away you are from the equator the temperature decreases. This is due to the sun’s rays.
Earth has three major climate zones. These zones are determined by latitude, or their position on Earth in relation to the equator
Altitude: The farther up you go the temperature decreases and it gets cold. Air is less dense and cannot hold the heat. Notice that there is snow at the top of this mountain. The higher up you go the colder it becomes. Therefore, mountain regions have colder temperatures.
Distance from the sea and bodies of water: The closer you are to the ocean the cooler the temperature.Water warms and cools much more SLOWLY than land.The temperature of water does NOT change as quickly as the temperature on land does.Land near water has milder weather because of the water’s influence. That’s why cities like Wilmington have cooler temperatures then cities like Raleigh.
Bodies of Water • Lakes help moderate the temperatures on the land • The nearby water causes an increase in moisture in the air, so in the winter these areas experience heavy snowfall. Lake Effect Snow
Urbanization: Living near or in a city also affect the temperature. Cities usually have warmer and rainier weather because it is surrounded by pavement , larger building and factories.
Winds: Depending of where the winds came from, they can increase or decrease temperature. Example: If cold winds blow, especially from the north, temperature is colder. If warm winds blow, usually from the south, the temperature is warmer. When wind blows against a mountain it causes the air to rise and cool. When it flows over the mountain and down the other side it causes the air to become cooler and takes the moisture from the clouds to create rain. This is called the rain shadow effect
Clouds Clouds consist of billons of tiny water droplets (and even ice crystals) floating in the sky and clouds form when rising air cools and the moisture in it condenses to water droplets.
Three things are needed for clouds to form: evaportation, cooling, and condensation Clouds can be named by their appearance or how they look and where they are located in the sky.
Types of Clouds • Cirrus: clouds are high, thin, and wispy white clouds that are made of tiny ice pieces and they bring change in the weather. • Stratus: are low, flat gray clouds which are layered. when stratus clouds are low to the ground, it creates fog. These clouds usually mean rain is coming. . • Cumulus: are white, puffy , clouds that look like cauliflower and make fair weather on sunny days. • Cumulonimbus: thunderheads clouds are huge, puffy, dark clouds, means heavy rain.
Altitude and Cloud Formation Clouds can also be described by the altitude/height at which they form. Clouds that form at high altitudes are described by the prefix cirro. So stratus clouds that form high in the sky are called cirrostratus.
Clouds that form in the middle of the sky are described by the prefix alto. A stratus cloud that forms at a middle altitude is called an altostratus cloud. • Alto cumulus alto stratus
Clouds that form at low altitudes or low in the sky are described by the prefix strato so a cumulus cloud that forms at a low altitude is called a stratocumulus cloud. Nimbostratus
Guess the Clouds • These clouds form when the wind is strong
Predictable Patterns of Weather HIGH pressure: cooler temperatures and less moisture. LOW pressure: hotter temperatures and more moisture
Air Mass A large body of air that has the same temperature and level of humidity throughout. cool air masses: where the land temperature is cool warm air masses: form over the land that is warm. dry air masses: form over dry areas wet air masses: form over wet areas like oceans.
Fronts • When air masses meet, a boundary called a front is formed, preventing the masses from mixing.
Fronts • Two different types of air masses do not mix, because of the different densities • Warm is less dense than cold air. • When warm air and cold air meet, warm air will rise above cold air.
Cold Front • Cold Front: What is it? At the cold front, the cold air cuts underneath the warm air and forces the warm air up a much steeper angle. At cold fonts the air is cooled quickly and forms a narrow band of thick cumulonimbus clouds. These produce heavy rain, snow or precipitation.
Cold Fronts bring: • Heavy rains • Thunderstorms • Sometimes snow
Warm Front • A warm air mass moves up and over a cold air mass. Direction of Front Warm Air Cold Air Mass
Warm Fronts Bring: • Rainy, drizzly weather • Often followed by clear, warm weather
Occluded Front • Two cold air masses move toward each other, warmer air between is pushed up Warm Air Cold Air Mass Cold Air Mass
Occluded Fronts Bring: • Cool temperatures • Plenty of rain and snow
Stationary Front • When a warm and cold air mass meets, but neither has enough energy to push against each other Cold Air Mass Warm Air
Stationary Fronts Bring: • Many days of overcast, rainy weather
Cold Front: A cold air mass moves under a warm air mass & pushes the warm air upward. .Cold fronts bring heavy rain and thunderstorms and cold weather. Warm front: forms when warm air bumps with colder air. This front brings rainy, drizzly weather, often followed by warm, clear weather . Occluded front: forms when a warm air mass is caught between two cold air masses. This brings cool temperatures and lots of rain and snow. Stationary front: occurs when a warm air mass and a cold air mass meet.. This brings many days of overcast and rainy weather.
Breezes affect the weather too • Valley breeze: The Sun warms the air above the valley during the day. The warm air rises and flows up the mountain. • Mountain breeze: At night the mountains cool down faster than the valleys do because of their elevation. The cool air sinks and flows down the mountain. • Sea breeze: The cool, high-pressure air over the ocean that flows toward land • Land Breeze: the movement of air created by cool air over land moving toward the ocean.
Sea Breeze • During the day, air over the ocean is cool. Cool air masses form over areas of high pressure. Air over the land is warmer, and as it rises, it creates an area of low pressure. • The cool, high pressure air over the ocean now flows toward the land, creating a sea breeze.
Land Breeze • At night, the air over the ocean is warmer than the air over the land. (WHY?) • The warm air over the ocean rises creating an area of low pressure. • The cool air over the land forms an area of high pressure and moves toward the ocean, producing a land breeze.
Mountain Breeze • At night, the mountains cool down faster than the valleys do, because of their elevation. • The cool air SINKS and flows down the mountain, causing a mountain breeze.