Transcript EarthScience_Topic 5 Meteorologyx

Meteorology and Climate
Meteorology
• Study of the earth’s atmospheric changes
• weather
Meteorologist
• Scientist who studies weather
weather
• Short term condition of the atmosphere
• Can change quickly, within days, hours, or minutes
Atmosphere
• The shell of gasses that surround the Earth
• Divided into layers based on temperature changes with altitude
Internal energy
• Inside the earth
• Causes:
• Radioactive decay (heat left over from the forming of Earth)
External energy
• Solar energy-from the sun
• Effected by: position of the sun in the sky
• The amount of solar energy absorbed or reflected by the atmosphere
• Insolation: incoming solar radiation
Selected Properties of Earth’s Atmosphere
• ESRT page ____________?
• Questions 1-16
How energy reaches earth
• Radiation:
• Energy transfer in the form of electromagnetic waves
• Can travel through empty space
• Most of the suns energy that reaches earth’s surface is in the visible range of
electromagnetic spectrum
Electromagnetic Spectrum ESRT page _____?
• Classification of radiation based on wavelength, frequency, and
amplitude
• 1.
• 2.
• 3.
• 4.
• 5.
• 6.
Heat waves= infrared and microwave radiation
Lead protects you from xray
Skin cancer results from too much UV radiation
Music is sent along as radiowaves
Nuclear bombs =gamma rays and x rays
sun= all types but mostly visible
Angle of insolation
• Altitude of the sun over the horizon, measured in degrees
• Highest altitude is 90 degrees
• 90 degrees- light is most concentrated, heat is more concentration,
warmer temperatures
• 45 degrees- light is more spread out, less concentrated, less heat and
cooler temperatures
1) Time of day
• Sunrise- sun is lowest in the sky=cooler temperatures
• Solar noon-sun is highest in the sky=warmer temperatures
• Sunset-sun is low in the sky= cooler
temperatures
2) Latitude
• The lower the latitude the higher the angle of insolation
• Equator- altitude of the sun is high all year, warm temperatures
• Poles- altitude of sun is low all year, cooler temperatures
3) Seasons
• In the northern hemisphere:
• Sun is highest in the sky in June-warmer temperatures, summer
• Sun is lowest in the sky in December-cooler temperatures, winter
Duration of Insolation
• Length of time the sun is over the horizon
• Depends on latitude and time of year
• Equator=12 hours all year long=no seasons
• As the latitude increases… summer: longer days, warmer
temperatures
• …..winter: shorter days, cooler temperatures
Duration of Insolation ?s
• 1-3
Atmospheric transparency
• Note packet
Reflection/Refraction/Absorption
• Light vs. Dark
• Dark Surfaces: absorb greater amount of heat
• Radiates the greatest amount of heat
• Light Surface: reflect the greatest amount of heat
• Radiate the least
Albedo: fraction of the
suns light that is
reflected from a
surface
Reflection/Refraction/Absorption
• Rough vs. Smooth
• Rough surfaces: more surface area to absorb more
• Smooth surfaces: less surface area, does not absorb as much
Land vs. Water
• Land heats up faster than water because water has a higher specific
heat
• Land cools down faster than water, because water has a higher
specific heat
• In the winter the lake may not freeze, in the spring-part of the lake
may still be frozen even though temperatures are warm
Specific Heat ESRT page….?
• The amount of heat (calories) needed to raise the temperature of one
gram of substance one degree Celsius
• The higher the specific heat, the more heat energy it requires to raise
the temperature of the material
• The lower the specific heat the faster it heats up
• If a material heats up quickly, it will also cool down quickly
Specific Heat questions a-e, 1-5
Terrestrial Radiation
• Note Packet
Greenhouse effect
• What is the greenhouse effect?
• What are the greenhouse gases? Where do they come from?
• What happens if we increase the amount of greenhouse gases in the
atmosphere?
• Create a diagram that shows what the greenhouse effect is.
• Explain the diagram
• Describe the runaway greenhouse effect. What is the example that is
used to talk about the runaway effect. Why?
Terrestrial Radiation Questions 1-9
Conduction
• Transfer of energy from molecule to molecule
• Most effective in solids, but can occur in gasses or liquids
• Ex: metal bar
•Con DUCT ion
Convection
• Energy transfer causes by the differences in density
• Occurs in fluids
• Most dominant heat transfer in Earth’s atmosphere
• Warm air rises, cold air sinks
Radiation
• Transfer of heat by
electromagnetic waves.
Weather variables
• Temperature: the measure of the average kinetic energy
• How fast the molecules move
• F Fahrenheit
• C Celsius
• K Kelvin
• Isotherms: lines that connect places of equal temperature
Temperature Conversions
• Pg 183
Air Pressure
• Weight of the Earths atmosphere
• Changes depending on the temperature
• Instrument: barometer
• Measured in inches or milibars
• Isobars: lines that connect places of equal barometric pressure
Mercury Barometer
• As air pressure pushes on the surface of the mercury in the dish, the
mercury travels up the tube
• As the pressure increases, the mercury rises up higher in the tube
• Cold air sinks-causes higher air pressure
• When pressure decreases, the mercury sinks out of the tube
• Warm air rises-causes lower pressure
Pressure conversions
• Pg 184
• Isotherm and Isobar wkst, lab
3) Relative Humidity
• Ratio between the amount of moisture in the atmosphere and how
much moisture the atmosphere can hold
• Measured in %
• When the air is holding as much water vapor as it can hold it is
saturated. RH100%
• The warmer the temperature is the more moisture it can hold
Hygrometer
Sling Psychrometer
• Dew Point Temperature:
• Temperature in which the air is saturated 100%
• Dry bulb- air temperature
• Wet bulb- temperature an air parcel cooled by evaporation of water
ESRT page ____
• Example 1: If the dry bulb temperature is 20 degrees C and the wet
bulb temperature is 15 degrees C, find the dew point temperature
and the relative humidity.
• Example 2: Find the relative humidity and dew point temperature
when the dry bulb temperature is 14 degrees C and the wet bulb
temperature is 9 degrees C
Humidity and Dew point calculations
• 186-187
Condensation
• Change of phase from water vapor to liquid water
• Examples: water on cold glass, dew on grass, fog, clouds, water on
mirror after a shower
3 things needed for condensation to occur
• 1) water vapor must be present
• 2)air must be saturated (relative humidity 100%)
• 3) condensation nuclei ex. Dust particles
Density of air
• Warm air rises because it is less dense
• Cold air sinks because it is more dense
Formation of Clouds
• Warm moist air rises
• Air expands and cools to the dew
point
• Air becomes saturated
• Water droplets form on dust
particles
• Clouds consist of water droplets
and ice crystals
Adiabatic cooling
• Cooling of a parcel of air as it rises through the atmosphere
• Dry adiabatic lapse rate- dry air cools faster
• Wet adiabatic lapse rate- moist air cools slower
Precipitation
• Cloud particles too heavy to remain suspended in the air fall to Earth
• Examples: rain, hail, sleet, snow, freezing rain
Wind
• The horizontal movement of air
• Caused by the uneven heating of Earth’s surface
• Differences in air temperature cause differences in air pressure
• The greater the difference in air pressure the faster the wind
• Named by the direction in which they come from
• North wind comes from the north
Sea Breeze
• Water heats up slower than land
• High specific heat
• Cooler air temperatures
• Air sinks
• High pressure
• Land heats up faster than water
• Low specific heat
• Warmer temperatures
• Air rises
• Low pressure
Land Breeze
• Water cools down slower than
land (stays warmer)
• High specific heat
• Warmer temperatures at night
• Air rises
• Low Pressure
• Land cools down faster than
water
• Low specific heat
• Cooler temperatures at night
• Air sinks
• High Pressure
Coriolis Effect
• The deflection of the winds and
ocean currents caused by the
rotation of Earth
• Deflection is to the right in the
northern hemisphere and to the
left in the southern hemisphere
High Pressure
• Cool/cold air
• Air sinks/goes down
• Air moves outward
• Clockwise
• No clouds
• No precipitation
Low Pressure
• Air rises
• Air moves inward
• Warm air
• Counter clockwise
• Clouds
• Precipitation likely
Planetary Winds diagram
• Planetary Winds and Moisture Belts in troposphere chart
Weather changes graphs
• Pg 191
Air masses
• Large region of the atmosphere with uniform temperature and
humidity
• cP continental polar dry and cold
• cT continental tropical dry and warm
• mP maritime polar
wet and cold
• mT maritime tropical wet and warm
• cA continental arctic dry and cold
• Write the abbreviation for the air mass in the map below on page
192.
Front
• The boundary between two air masses
• ESRT: ________?
Cold Front
• Cold air pushes the warm,
moist air upward
• Cold air is located behind the
front
• The greater the difference in
temperatures, the more likely
there will be a major storm
• Usually pass quickly
• Brings cold but clear weather
conditions
Warm Front
• Warm air gently rolls over
the colder air
• Warm air is located behind
the front
• Conditions are usually
cloudy and rainy for
several hours
• Usually pass slowly
• Brings warmer but rainy
weather conditions
Occluded front
• Occurs when a cold air mass
overtakes a warm mass and
overtakes another cold air mass
• Precipitation is possible but not
definite
• Very slight temperature change
Stationary Front
• Notice no arrows to show direction in
the weather map symbols
• Stationary means the front is not
moving
• Final direction of movement is difficult
to predict
• Winds are blowing in opposite
directions on each side of the front
• Clouds can last for days
Fronts are usually
associated with…
• Clouds
• Precipitation
• Change in
temperature
• Change in wind
direction
• Fronts packet
Station Models
Pressure
• On a station model, barometric pressure is always written in a three
digit format.
• Converting from millibars: drop the 9 or 10 in the front and loose the
decimal point.
• 1009.3 = 093
• 1022.2 = 222
• 994.9 = 949
Pressure
• Converting from the station model format to millibars:
If the first number on the station model is 0-4, place a 10 in the front of the
number.
If the first number on the station model is 5-9, place a 9 in the front of the
number.
In either case, place a decimal point between the last 2 numbers
Converting from the station model format to
millibars:
• 146 = First number is between 0 and 4. We put at 10 in front.
• Number becomes 10146.
• Next step is to place a decimal in between the last two
numbers.
• Our final answer is 1014.6
•978 = First number is between 5 and 9. We put a 9 in front.
•Number becomes 9978.
•We put a decimal in between the last two.
•Our final answer is 997.8
Need to Know
• The closer the air temperature is to the dew point temperature the
greater the chance for precipitation
• Weather motion
• wunderground
Storms activity
Create a disaster plan
• Plan
• Supply kit