Download Weather Chp. 2

Weather Chp. 2
Energy of the Atmosphere
Sun – 98% of the energy in Earth’s atmosphere
comes from the sun in the form of
electromagnetic waves.
Radiation – is the direct transfer of energy by
electromagnetic waves.
-visible light
most
- infrared
-ultraviolet
Blue sky – is the product of the reflection and
scattering of light in all directions causing the
short wavelengths of blue and violet to appear.
Dusk and Dawn – the scattering of longer
wavelengths (red and orange) due to light
traveling through more atmosphere.
Mid-day
Dusk/dawn
Energy at the surface
1. Absorbed by earth
2. Reflected back to atmosphere
3. Absorbed by the clouds and gasses in atmo.
Green house effect – is when energy is
absorbed by water vapor, CO2, methane, and
other gasses in the air, causing a warm
“blanket” to form in the atmosphere.
Temperature
Thermal energy – the total energy of motion in
the molecules of a substance.
Temperature – is the average amount of energy
of motion of each molecule of a substance, thus
the measure of how hot or cold a substance is.
http://www.colorado.edu/physics/2000/waves_particles/wavpart2.html
Thermometer – a thin glass tube with a bulb on
one end that contains a liquid (colored alcohol)
---- temp----when a liquid is heated up it will expand!
This expansion is restricted to going only two
directions in a thermometer, UP or Down! When it
rises it indicates more energy in the liquid
molecules and causing the liquid to expand up.
When heat (energy) is lost the molecules will
come closer together taking up less space and
indicating a lower temp.
Heat Transfer
3 types
1. radiation – the direct transfer of energy by
electromagnetic waves.
2. Conduction – the direct transfer of heat from
one substance to another substance that it is
touching.
3. Convection – The transfer of heat by the
movement of a fluid.
Pg. 51
radiation
eyr
Winds
Wind – is the horizontal movement of air from an
area of high pressure to an area of lower
pressure.
- pressure differences are caused by
an unequal heating of the atmosph.
- cold dense air sinks and warm air
rises causing a movement of air (wind)
high pressure vs. low pressure.
Anemometer – measures wind speed.
Wind chill is the cooling of warm
blooded mammals do to heat loss
from wind.
Wind direction – Named (west wind) by the
direction is coming from. So, a west wind
would be coming from the west and blowing
toward the east.
Local wind – winds that blow over short
distances. Ste. Gen to Cape or smaller, do to
unequal heating of surface of Earth.
Sea breeze – wind blowing inland from the sea.
Earth heats up quicker less
pressure than air over water more
pressure. Day time.
Land breeze – wind blowing out to sea from the
land, due to opposite of sea breeze. Night time
Monsoons – sea and land breezes over a large
region that change direction with the seasons.
Global winds – (created by unequal heating)
winds that blow steadily from specific directions
over long distances. The movement of air from
the equator to the poles as a result of
convection is a global wind. See pg 59.
Coriolis Effect – The way Earth’s rotation makes
winds curve.
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/f
w/gifs/coriolis.mpg
Jet stream – A high level stream of fast moving
air. At altitudes of 6 miles high and at
speeds of 180km to 350km.
El Nino
• El Nino - (El Nee-nyo) is the warming of
water in the Pacific Ocean.
• Rain and flooding along the Pacific Coast
• Warm water disrupts the food chain of fish,
birds, and sea mammals.
• Tornadoes and thunderstorms in the
southern US
• Fewer than normal hurricanes in the
Atlantic
La Nina
• La Nina - (Lah Nee-Nyah) is the cooling of
water in the Pacific Ocean.
• Snow and rain on the west coast
• Unusually cold weather in Alaska
• Unusually warm weather in the rest of the USA
• Drought in the southwest
• Higher than normal number of hurricanes in the
Atlantic
• http://esminfo.prenhall.com/science/geoanimatio
ns/animations/26_NinoNina.html
Water Cycle
• Amount of water remains the same as it
moves through the cycle
• Fresh water is limited
• All living organisms need liquid water
• Earth’s water is continually being
recycled
Evaporation – process by which water molecules
escape into the air by radiant energy from
the sun changing water into a gas (water
vapor).
Relative humidity – the percentage of moisture
the air holds relative to the amount it could
hold at a particular temperature.
Psychrometer – instrument used to measure the
amount of R. humidity in the air. It consist of two
thermometers, one wet and one dry.
Cloud formation
Clouds form when water vapor in the air becomes
liquid water or ice crystals. Water vapor
changing into a liquid----CONDENSATION
The temperature at which condensation begins is
called dew point.
Cumulonimbus – Thunderstorm clouds that
produce severe weather, tornadoes, hail, strong
winds. Have anvil shape to top of cloud.
Clouds
Cumulus – usually indicate fair weather. 2 to 7
miles in the sky (cotton balls).
Cirrus – Feathery or fibrous in appearance. Very
high altitudes usually between 6 and 12
kilometers. Indicate the onset of rain or snow in a
few hours.
Stratus clouds – smooth gray clouds that cover
the whole sky and block out the sun are
called stratus clouds. These clouds produce
steady, light precipitation.
Precipitation – Water vapor that condenses and
forms clouds that can fall to the Earth as rain,
sleet, snow, freezing rain or hail.
sleet – water droplet that freezes when it
falls through cold air. (winter)
snow – forms when water vapor changes
directly to a solid.
Hail – ice balls that fall after water is frozen
in the air then pushed further up and collects
more water and freezes again, over and
over until it becomes to heavy to stay
suspended in the air. The stronger the uplift
the larger the hail stone. (summer)
Freezing rain – rain that freezes upon contact
with the ground.
• Isobar
A line on a weather map connecting places
that have the same air pressure.
high-pressure system
A generally calm and clear weather system
that occurs when air sinks down in a highpressure center and spreads out toward
areas of lower pressure as it nears the
ground.
(More dense cold air)
low-pressure system
A large and often stormy weather system
that occurs when air moves around and
into to a low-pressure center, then moves
up to higher altitudes.
(Less Dense Warm Air)
Storms
• Caused by:
• Changes in temperature & drop in
barometric pressure
• Ex: Hurricanes are a low pressure mass
over tropical (warm) water
Weather Fronts
• Air mass-a huge body of air that has
similar temperature, humidity, and air
pressure
• Front-the area where two air masses meet
and do not mix
• Dense,cold air moves underneath the less
dense warm air, pushing it up
Front Types
• Cold front-rapidly moving cold air mass
that runs into a slowly moving warm air
mass
• Move quickly, causing violent storms
• Warm front- warm air that collides with
cold air
• Moves slowly, causing fog or rain for days,
and in the winter, snow
Cold Front
(More Dense cold Air)
Cold Front
Warm Front
(Less Dense Warm Air)
Warm Front
Stationary Front
Stationary Front
Weather Forecasting
• Meteorologists-scientists who study
weather and try to predict it
• Forecasting has greatly improved due to
computer technology
• Collecting weather data has improved
because of satellites and balloons
Seasons and Climate
• Earth has seasons because Earth’s axis
tilted as it moves around the sun
• Winter-axis tilted away from sun resulting
in shorter days and indirect rays
• Summer-axis tilted toward sun resulting in
longer days and direct rays
Climate
•
•
•
•
•
Caused by:
Altitude
Latitude
Mountain barriers
Proximity (closeness) to oceans
• Climate is classified by precipitation and
temperature based on these factors