Weather is the atmosphere at a place and time as regards heat, dryness, sunshine, wind, and rain. The weather is just the state of the atmosphere at any time, including things such as temperature, precipitation, air pressure and cloud cover. Daily changes in the weather are due to winds and storms. Seasonal changes are due to the Earth revolving around the sun. Cycles of weather changes are the seasons. Weather Airplanes gather data at certain altitudes over some geographical regions, and they are often used to track all kinds of storms. With some simple close observation important data is collected to help scientists know where a certain storm might hit next and know what it is actually doing.

Weather Our Earth is surrounded by a layer of air called atmosphere. Sometimes air becomes hot and sometimes becomes cold. This change in air is known as weather. Weather keeps changing from day to day sometimes from hour to hour. Biometeorology is the science that studies how weather affects living things.

Types of Clouds

Clouds are given different names based on their shape and their height in the sky. Some clouds are near the ground. Others are almost as high as jet planes fly. Some are puffy like cotton. Others are grey and uniform.The highest clouds in the atmosphere are cirrocumulus, cirrus, and cirrostratus. Cumulonimbus clouds can also grow to be very high. Mid-level clouds include altocumulus and altostratus. The lowest clouds in the atmosphere are stratus, cumulus, and stratocumulus. https://scied.ucar.edu/sites/default/files/images/long-content-page/%3Cem%3EEdit%20Long%20Content%20Page%3C/em%3E%20Clouds%20Types/cloudchart.gif

High Clouds: Cirrus- Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance. Cirrus clouds are always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals. Cirrostratus-Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky. A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus Cirrocumbus-Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. In general Cirrocumulus represents a degraded state of cirrus and cirrostratus both of which may change into it and is an uncommon cloud. There will be a connection with cirrus or cirrostratus and will show some characteristics of ice crystal clouds.

Mid-Clouds:

AltoStratus-Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky. They are thin enough to regularly reveal the sun as if seen through ground glass. Altostratus clouds do not produce a halo phenomenon nor are the shadows of objects on the ground visible. Altocumulus-White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse.When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.The most common mid cloud, more than one layer of Altocumulus often appears at different levels at the same time. Many times Altocumulus will appear with other cloud types. Nimbostratus-The continuous rain cloud. Resulting from thickening Altostratus, This is a dark gray cloud layer diffused by falling rain or snow. It is thick enough throughout to blot out the sun. The cloud base lowers into the low level of clouds as precipitation continues. Also, low, ragged clouds frequently occur beneath this cloud which sometimes merges with its base.

Low Clouds: Cumulus-Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal Stratus- A generally gray cloud layer with a uniform base which may, if thick enough, produce drizzle, ice prisms, or snow grains. When the sun is visible through this cloud, its outline is clearly discernible. Often when a layer of Stratus breaks up and dissipates blue sky is seen. Cumulonimbus:The thunderstorm cloud, this is a heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume.Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base. They produce precipitation, which sometimes is in the form of virga. Cumulonimbus clouds also produce hail and tornadoes. Stratocumulus-Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm's length).

Weather Fronts

Cold Front: A heavy cold air mass pushes a warm air mass.
Warm Front: A warm air mass follows a retreating cold air mass.

Seasons A weather (state of atmosphere) front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. In surface weather analyses, fronts are depicted using various colored triangles and half-circles, depending on the type of front.

The Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of the energy is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.

Greenhouse gases include the following:

Water
Vapour
Carbon Dioxide
Methane
Nitrous oxide
Ozone
Artificial chemicals such as chlorofluorocarbos (CFCs).

Climate ranks by their contribution to the greenhouse gas effect:

water vapor, which contributes 34–70% carbon dioxide, which contributes 9–26% methane, which contributes 4–9% ozone, which contributes 3–8%

The absorbed energy warms the atmosphere and the surface of the Earth. This process maintains the Earth's temperature at around 33 degrees Celsius warmer than it would be, letting life on Earth exist.

Greenhouse Effect.

Step 1: Solar radiation reaches the Earth's atmosphere.

Step 2: The rest of the sun's energy is absorbed by the land and the oceans, heating the Earth.

Step 3: Heat radiates from Earth towards space.

Step 4: Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the Earth warm enough to sustain life.

Step 5: Human activities such as burning fossil fuels, agriculture and land clearing are increasing the amount of greenhouse gases released into the atmosphere.

Step 6: This is trapping extra heat, and causing the Earth's temperature to rise.

Global Warming

Global warming and climate change are terms for the observed century-scale rise in the average temperature of the Earth's climate system and its related effects. Multiple lines of scientific evidence show that the climate system is warming.

Global Warming is a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. The recent increase in the world's temperature that is believed to be caused by the increase of certain gases (such as carbon dioxide) in the atmosphere

Global warming is the current increase in temperature of the Earth's surface (both land and water) as well as it's atmosphere. Average temperatures around the world have risen by 0.75°C (1.4°F) over the last 100 years about two thirds of this increase has occurred since 1975. In the past, when the Earth experienced increases in temperature it was the result of natural causes but today it is being caused by the accumulation of greenhouse gases in the atmosphere produced by human activities.

We, as humans also play a role to the global warming topic. We need to be more cautions as to what we do and what the consequences could be because we also damage the earth by our actions. Global warming is an issue that affects us all because we also suffer from it. Also animals get affected by this and are now becoming extinct, so we need to make conscience of our actions and take good care of our earth.

Winds

Usually it all begins with the sun’s radiation, which is consumed differently on the earth’s surface. The earth's surface is heated differently because of scenario like cloud cover, valleys, water bodies, mountains, and desert lands.

Because of this uneven heating, there are bound to be earth surfaces that vary a lot in temperature. Air on surfaces with higher temperatures will then begin to rise because it is lighter. As the air rises, it creates low atmospheric pressure. Air on surfaces with cooler temperatures sink.

Wind Classification

Calm Air: These are usually felt as an airy condition. This class is not enough, even to fly a feather kite. It is also called light wind, and it has a speed of about 1km/hr. Calm air will be noticed by smoke rising vertically from a chimney. They have a Beaufort Number 0.
Gentle Breeze: have speeds of about 12-20km/hr, they are named Gentle-Moderate Winds in the USA.
Moderate Breeze: Moderate winds have speeds of about 20-38km/hr. They are enough to fly a kite and keep it going higher and higher. They can cause moderate waves with whitecaps on the sea and make trees whistle.
Gale Winds: have speeds of about 75km/hr and more. They can be very destructive and they can bring a lot of broken branches and twigs from trees. They create high tidal waves and rolling seas. They can also rip off roofs of building.

Types of Winds

Local Winds
Local Winds are those that are created as a result of scenery like vegetation, mountains, or water bodies. Commonly they change very often and we can hear about this clamatic chang changes on the weather forecast on TV every day. They can move from mild to extreme winds in just hours. Some good examples of local winds are sea breezes and land breezes, and mountain and valley breezes. Local winds cover very short distances.

Global Winds

Global Winds are really large air masses that are created mainly as a result of the earth’s rotation, the shape of the earth and the sun’s heating power.

The Doldrums: This is the very low pressure area along the equator where prevailing winds are calmest. This low-pressure area is caused by the constant heating of the sun. This belt extends to about 5° north and south of the equator.
Horse Latitudes: This are about 30 degrees latitude, both north and south of the equator, the air cools enough to sink toward the Earth's surface again, forming a belt of descending high pressure air.
Trade Winds: These are extremely steady winds blowing from sub-tropical high pressure areas (30°N and S) towards the equatorial low pressure belt. These winds should have blown from the north to south in Northern Hemisphere and south to north in Southern Hemisphere, but, they get deflected to the right in Northern Hemisphere and to the left in Southern Hemisphere due to Coriolis effect and Ferrel’s law.
Westerlies: These winds blow from sub tropical high pressure belts towards sub-polar low pressure belts.
Jet Streams: Narrow bands of high altitude, high speed winds are located in the prevailing westerlies of both the northern and the southern hemispheres.
Monsoons: These winds are seasonal winds and refer to wind systems that have a pronounced, seasonal reversal of direction.
Land Breeze: At night, land masses cool quicker than sea due to rapid radiation which results in high pressure over land and low pressure over sea.

Severe Weather

Some of the most feared and destructive events in life are due to severe weather, often in the form of hurricanes, tornadoes, thunderstorms, or a combination of these. Hurricanes are the single greatest natural threat to human life worldwide.

Hurricanes

Hurricanes (called typhoons in the western Pacific Ocean and cyclones in India) are lows, or cyclones, that form over oceans in the tropics. The period of June through November is called the "hurricane season," as almost all hurricanes form during these months, especially during August, September, and, October. At this time of the year the tropics receive a tremendous amount of energy from the sun, causing enormous amounts of ocean water to evaporate. Warm, moist air move in, forms above the surface of the ocean. Huge masses of colder, heavier air move in, forcing the warm, moist air upward creating violent, whirling movements of air that spiral toward the center of the storm. With winds speeds of 64 kilometers to 120 kilometers per hour.

When winds are below 74mph, it is called a tropical storm. When winds reach above 74mph, it is considered to be a hurricane. The center of a hurricane known as the “eye” is very calm and contains almost no wind.

Hurricane Sandy Facts

Hurricane Sandy was a post-tropical cyclone that swept through the Caribbean and up the East Coast of the United States in October of 2012. The hurricane started as a tropical wave in the Caribbean and turned quickly into a tropical storm in just 6 hours. It was upgraded to a hurricane on Oct. 24 when it reached 74 mph winds. The National Hurricane Center says that the tropical force winds extended 820 miles at their widest. Sandy’s pure kinetic energy for storm surge and wave destruction potential reached a 5.8 out of 6 on the National Oceanic and Atmospheric Administration’s scale. The total death toll reached 285, including at least 125 deaths in the United States.

https://upload.wikimedia.org/wikipedia/commons/thumb/a/af/NOLA9thFloodedBetsy.jpg/200px-NOLA9thFloodedBetsy.jpg

Hurricane

A hurricane is about 480 kilometers wide the strongest winds are in a narrow ring extending out about 40 kilometers from the center. Northern hemisphere the hurricanes travel west to northwest in a northeasterly direction. Greatest damage is caused by the waves they produce. Waves could be 4.5 meters or more above normal sea level.

Tornadoes

Tornadoes, also called funnel clouds or twisters, are the smallest, most violent, and most short-lived storms. When they occur almost exclusively in the United States. Although they can occur in any level land area, and all of the forty-eight contiguous states have experienced them, the region that seems most vulnerable to tornadoes beings at Texas and fans out to the east and north from that point through a path called the "tornado belt". Usually, cold, heavy air pushes its way under warm air masses. Sometimes, however, a layer of cold, dry air to pushed over a layer of warm, moist air. When this happens, the warm, moist air can quickly force its way up through the layer of cold air in a spiral fashion, forming a tornado. The tunnel of the tornado may or may not reach the ground, and sometimes it touches down at one point, lifts for a while, then touches down again a short distance away. It moves in a wandering path at speeds of about 40 to 64 kilometers per hour. The spinning winds in this powerful updraft can reach speeds up to 800 kilometers per hour. Tornadoes can be rated on an F-Scale from F0-F5, with F0 being the smallest and F5 being the largest. F5 tornadoes can have winds that reach up to 200mph or more.

Tornadoes

Tornadoes form when different temperatures and humidity meet. The spinning of air remain unseen until it picks enough dust for its shape to be visible. Tornadoes can rip roofs off buildings and sometimes the winds take entire buildings.

Thunderstorms

Cumulus clouds are usually fair-weather clouds, but they can respond to unstable atmospheric conditions, grow tall and dark, and become cumulonimbus clouds, or thunderheads. Thunderstorms come from cumulonimbus clouds, and they are accompanied by lightening, thunder, strong gusts of wind, heavy rain, and sometimes hail. Thunderstorms are associated with strong updrafts of warm, moist air and equally rapid downdrafts of cool air. Water accumulation in a thunderhead can reach 500,000 or more.

Some of the most severe occur when a single thunderstorm affects one location for an extended time.

Forecasting the Weather

Weather Forecasting:

Meteorology= Study of Weather

Meteorologists: A person who studies and forecasts

Instruments required for weather forecasts:

Thermometers for Temperature= Instruments for measuring Air Masses
Barometers for Air Pressure
Wind vanes for Wind direction
Anemometers for Wind Speed
Hygrometers for Relative Humidity
Rain Gauges for Rainfall
Measuring Sticks for Snowfall

Methods of Gathering Data

3,500 ground stations contribute weather data.

Radiosonde and Dropsonde

> Radiosonde:

- Lifted high into atmosphere by balloon to record data.

- At 90,000 ft balloon pops and radiosonde parachutes back to earth for reuse.

- 100's released everyday at the same time worldwide.

> Dropsonde:

- Dropped from airplanes for weather data from a precise location

Weather Satellites

> Polar orbiting

> Geostationary

Radar is not blocked by cloud cover.

> Doppler radar relatively new in its implementation by weather services, can also determine the speed and direction of storms.

Seasons

What is a Season, well this is referred to the regular repeating pattern of change in weather during the year this is when we talk about the four seasons which most of us are familiar with summer, winter, fall, and spring. Even though the temperatures and the amount it rains vary from year to year it is safe to say that the seasonal patterns are distinctly consistent. Not all parts of the globe have the same affect some places it might be cold all year long but in others it might be hot all year around, this does not mean that it is either cold or hot there are some place that do experience both warm and cold seasons but this is when people have to adapt to the climate or seasonal changes. For the most part most of the time the globe is experiencing changes is because of way the earth is facing the sun.

A season is a division of the year[1] marked by changes in weather, ecology and hours of daylight. Seasons result from the yearly orbit of the Earth around the Sun and the tilt of the Earth's rotational axis relative to the plane of the orbit.[2][3] In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to go into hibernation or to migrate, and plants to be dormant.

Earth Seasons:

Spring, Fall, Summer, Winter

Climate

Climate is the average weather usually taken over a 30-year time period for a particular region and time period. Climate is not the same as weather, but rather, it is the average pattern of weather for a particular region. Weather describes the short-term state of the atmosphere.What is our climate system?

Climate System

Atmosphere-The atmosphere covers the Earth. It is a thin layer of mixed gases which make up the air we breathe. This thin layer also helps the Earth from becoming too hot or too cold.

Oceans-Oceans cover about 70 percent of Earth's surface. Their large size and thermal properties allow them to store a lot of heat.

Land-Land covers 27 percent of Earth's surface and land topography influences weather patterns.

Ice- Ice is the world's largest supply of freshwater. It covers the remaining 3 percent of Earth's surface including most of Antarctica and Greenland. Ice plays an important role in regulating climate, because it is highly reflective.

Biosphere- The biosphere is the part of Earth's atmosphere, land, and oceans that supports any living plant, animal, or organism. It is the place where plants and animals, including humans, live.

The ocean influences Earth's weather and climate patterns.

Indicators to climate change:

Global Greenhouse gas emissions- Worldwide, releases of greenhouse gases from human activities rose by 35 percent from 1990 to 2010. Emissions of carbon dioxide, which are responsible for about three-fourths of total releases, elevated by 42 percent over this period.

Atmospheric concentrations of greenhouse gas- Concentrations of carbon dioxide and more greenhouse gases in the atmosphere have elevated since the beginning of the industrial era. Almost all of this increase is due to human activities. From 1990 to 2015, the total warming effect from greenhouse gases added by humans to the Earth’s atmosphere increased by 37 percent.

Climate Forcing- Climate forcing states to a change in the Earth’s energy balance, causing a warming or cooling effect over time. An elevation in the atmospheric concentrations of greenhouse gases make positive climate forcing, or warming effect.

Earth's Climate System

Climate is a long term atmospheric conditions in a region

Earth’s climate includes interactions of: Atmosphere Hydrosphere Geosphere Biosphere Cryosphere

Climate system is the exchanges of energy and moisture between these spheres

Climatologist

A scientist who studies a number of characteristics of the atmosphere the two major elements that determine climate are average temperature and average annual precipitation.

People who study climate are called climatologists. Climatologists use temperature and precipitation records to define what a place’s “normal” climate is like. They do this by averaging 30 years of temperature and precipitation records. They also keep track of this information by making climographs for cities and regions.

Example Climograph A climograph is a graph that shows monthly average temperature and precipitation for a place. The graph to the left is an example of a climograph for Chicago, Illinois. The green bars show the amount of precipitation each month, and the red line shows the average temperature each month. See more climographs for U.S. cities and cities around the world.

Climatologists can also look back through years of records to determine how often droughts happen in a specific city or region. Remember, drought can happen anywhere, but it may happen more often in some areas than in others!

A rain gauge helps us keep track of how much rain we get, but keeping track of drought isn’t that simple. Climatologists use many different indicators to monitor (watch) when drought begins and ends and also how severe the drought is. Temperature and rainfall are indicators, but so are water levels in streams, rivers, and lakes, the amount of moisture in the soil, and the amount of snowpack in the mountains.

Climatologists compare this information with what is “normal” for an area to determine whether a drought is beginning or ending, or even how bad the drought might be. For example, doctors have calculated that a person’s normal body temperature is 98.6 degrees Fahrenheit. If you aren’t feeling well, the doctor or your parents will take your temperature. How much above or below normal (98.6°F) it is can indicate how sick you might be. Climatologists do the same thing to let people know if there is a drought and how severe the drought is.

The Greenhouse Effect

The greenhouse effect is energy that stays in the atmosphere that normally would infrared back into space. Certain gasses such as carbon dioxide absorbs this energy and does not allows the radiated energy to the space. The surface absorbs the sunlight. The sunlight rays go back to space this is called the infrared radiation. The greenhouse effect absorbs some of this energy and make our atmosphere warmer. People are adding more CO2 to the atmosphere.The greenhouse effect warms specially the first layer of the atmosphere to keep earth warm. Without the greenhouse effect Earth could be a much colder place. If the air becomes too hot the food change could be in danger. If food chain is at dangers it can cause bigger problem worldwide. This extra gasses affect the Earth atmosphere temperature warmer temperature will affect the living organisms on Earth.

The effect of gradual increase in heat of earth's atmosphere and surface is called Global Warming. The main causes of Global warming are Greenhouse effect and increase of Greenhouse gasses. Adverse effects of Global warming will be extreme climate conditions, rise in sea levels, etc.

Atmosphere's Greenhouse Effect

Global warming – increase in Earth’s global temperatures

Greenhouse effect – keeps Earth’s surface habitable

Incoming heat energy is shorter wavelengths

Longer wavelengths – some trapped, some escape, net warming effect

Coriolis Effect

Coriolis Effect-is an important meteorological force that is used to predict the path of storms and explains why a projectile will not hit a target at a great distance if the Earth’s rotation is not accounted for.

Monsoons

Monsoon is a seasonal wind produced by the difference in heating of oceans and land-masses during summer and winter.

Land-Sea Breezes

Land warms faster than the water during the day and cools faster than the water at night.

Evaporation

Water evaporation is the process of water changing from a liquid into an invisible gas. Molecules are regularly moving the faster changing molecules at the surface reach and go off into the air becoming molecules of water vapor.

Evaporation is the process by which water changes from a liquid to a gas or vapor. Evaporation is the primary pathway that water moves from the liquid state back into the water cycle as atmospheric water vapor. Studies have shown that the oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpiration.

A very small amount of water vapor enters the atmosphere through sublimation, the process by which water changes from a solid (ice or snow) to a gas, bypassing the liquid phase. This often happens in the Rocky Mountains as dry and warm Chinook winds blow in from the Pacific in late winter and early spring. When a Chinook takes effect local temperatures rise dramatically in a matter of hours. When the dry air hits the snow, it changes the snow directly into water vapor, bypassing the liquid phase. Sublimation is a common way for snow to disappear quickly in arid climates. (Source: Mount Washington Observatory)

Humidity

Humidity is the moisture in the air and specific humidity is the actual amount of water vapor present. Relative humidity is a measure of the amount of moisture the air contains compared with the maximum amount it could hold at that temperature.

Precipitation=

Precipitation is a form of moisture that falls from the atmosphere consists of snow,rain,sleet,and hail.

Rain

Water vapor condenses in the atmosphere and forms tiny droplets the slightest air movement is enough to keep them from falling to the ground.

Snow

When the air temperature is below freezing water vapor condenses in the form of ice crystals.

Sleet

When raindrops fall from the cloud they pass through colder air and freeze before they reach the ground is called sleet is frozen rain.

Hail

Is formed when there are strong upward air currents within a thundercloud during a summer thunderstorm while the raindrops form are carried high into a layer of very cold air, and the raindrops freeze. Hail can form in many different sizes. They can either be as small as a marble, or the size of a baseball.

External Links

National Geographic Climate and Weather Video

Science: An Elementary Teacher’s Guide/Weather, seasons, and climate

Contents

Types of Clouds

Weather Fronts

The Greenhouse Effect

Global Warming

Winds

Wind Classification

Types of Winds

Severe Weather

Hurricanes

Hurricane Sandy Facts

Hurricane

Tornadoes

Tornadoes

Thunderstorms

Forecasting the Weather

Methods of Gathering Data

Seasons

Climate

Climate System

Climatologist

The Greenhouse Effect

Coriolis Effect

Monsoons

Land-Sea Breezes

Evaporation

Humidity

Precipitation=

Rain

Snow

Sleet

Hail

External Links