SMU Meteorology Chapter 1, 2, 3 Exam

Earth

-Unique among the planets

-only planet with life

-Oxygen (O₂) to breathe and Ozone (Oз) for UV protection

-Water Vapor-Liquid Water-Ice

How humans influence the weather

Ozone depletion, air pollution, global warming and Artificial Weather Modification (we can make it rain, snow, disperse fog & prevent freezes)

Meteorology

the study of the atmosphere and its weather

Weather

state of the atmosphere at any given time and place, constantly changing

Climate

The 'average' of a variety of weather conditions usually over a 30 year period, includes averages and extremes

Components of weather and climate

-air temperature

-humidity

-type and amount of clouds

-type and amount of precipitation

-air pressure

-speed and direction of wind

(climate cannot predict weather)

Direction of wind

defined by the direction FROM WHICH it is blowing (northerly wind blows FROM the north)

The Nature of Scientific Inquiry

science seeks to discover patterns in nature in order to predict what a natural phenomena will do, assumes the natural world behaves in a CONSISTENT and PREDICTABLE behavior, no such thing as revealed truth

(make an observation and attempt to come up with an explanation)

Hypothesis

an untested explanation of observed facts, must be tested to gain legitimacy

Theory

A hypothesis that has passed many tests & is widely accepted

Law

an observation of the phenomenon that the theory attempts to explain

Scientific Method

1. Make an observation

2. Gather data

3. Form hypothesis

4. Test hypothesis

5. Establish theories

6. Data/results must be shared for critical examination & further testing

7. if results cannot be replicated, then they are irrelevant

Earth's Spheres

has 4 main spheres

-Geosphere

-Atmosphere

-Hydrosphere

-Biosphere

Geosphere

solid parts of the Earth (Crust, Mantle, Core), extends from the surface to the center of the planet, ~6400km/~4,000 miles

Atmosphere

mixture of gases that envelope the Earth, 99% of the atmosphere is within ~30km (~18 miles) of the Earth's surface

Without the atmosphere...

life would cease

-no air to breathe

-deadly radiation would reach the ground

-Earth would fry during the day

-Freeze solid at night

Hydrosphere

the water of the earth, oceans are 71% of Earth's surface, the rest of the hydrosphere is lake, rivers, streams, glaciers (Cryosphere: the solid form of water), underground water, clouds

Biosphere

life forms of Earth, anywhere where water can be found, there is usually some form of life in it

System

a system is a group of interdependent parts that form a complex whole

Earth System Science

Earth's land, water, air and life-forms are all interconnected

Major components of the atmosphere

Oxygen

Nitrogen

Carbon Dioxide

Water Vapor

Aerosols

Ozone

OG atmosphere

hydrogen, helium methane, ammonia, carbon dioxide

Oxygen & Nitrogen

Makes up 99% of the volume

21% oxygen

Carbon dioxide (CO₂)

0.0408%, Absorbs energy leaving Earth, radiates some back, keeps Earth warmer than it should be, Greenhouse Gas

Earth's average temperature

59°F, without greenhouse gases, Earth's average temp= 0°F, frozen solid from Pole to Pole

Water Vapor (H₂O)

most effective greenhouse gas, 0% to 4% of atmosphere, clouds/precipitation come from water vapor

Aerosols

Dust, soot, ash, smoke, sea salt crystals, pollen, grains and meteoroids! Absorb/reflect solar radiation, assists in cloud formation, makes vivid red sunrise/sunset

Ozone (Oз)

Greenhouse gas, toxic when inhaled, makes life on earth possible, it absorbs most of the deadly incoming UV radiation from the sun, ozone layer is thinning as a natural process but we have made it much worse

Vertical Structure of the Atmosphere

Air pressure, temperature

Chlorofluorocarbons (CFCs)

manmade, refrigerants & aerosol products like hair spray, spray paint, stays in the atmosphere for decades

Air pressure

weight of the air overhead, Always decreases with height but at a slower rate as you get higher, 14.7lbs (1013 mb) for every square inch on your body, you are carrying thousands of pounds each day

Temperature of atmosphere

Usually decreases with height in lower temperatures, pre 1902 thought the temp at top of atmosphere would approach absolute zero, French Scientist Leon Philippe Teisserence de Bort found temp actually leveled off at ~7.5miles above sea level

absolute zero

~460 degrees below zero Fahrenheit or -273.15 degrees Celsius,

environmental lapse rate

the rate of temperature decrease with increasing height in the troposphere

average environmental lapse rate

temperature drops 6.5 degrees C/km

Troposphere

(sea level to ~12km, ~7.5mi), temperature decreases with altitude

Tropopause

marks the top of the troposphere and its lowest temperature, temps abruptly stop decreasing with height here

Height of tropopause

-changes with latitude

-thinnest over the poles (~9km, ~5.5 miles thick)

-Thickest over the equator (~16km or ~10 miles thick)

Stratosphere

(~12km to ~50km, ~7.5 miles to ~30 miles), temperature starts nearly constant with height but then abruptly increases with height because of the absorption of UV radiation by O3, ~90% of ozone in the atmosphere is found here, Stratopause marks top of stratosphere and its warmest temperature

Mesosphere

(~50km to ~80km, ~30mi to ~50 mi), temperatures decreases with height, Mesopause marks the top of mesosphere and has the atmosphere's coldest temperature

Thermosphere

(above ~80km, ~50mi), thermosphere has no well-defined upper limit, temperature rises to over 1800 degrees F, freeze and fry at the same time (side of you facing the sun would fry, backside would freeze)

Ionosphere

(~80km to ~400km, ~50mi to ~250mi), part of lower thermosphere, sun fares send high energy particles at Earth, Earth's magnetic field captures them, solar particles energizes the N2 & O2 molecules, make northern lights/Aurora Borealis (green=N2 & red=O2)

Ionosphere's role in the Northern and Southern Hemisphere

Aurora borealis are the Northern lights and aurora australis are the southern lights

Greenhouse gases

water vapor (most important), ozone, Carbon dioxide, methane, and nitrous oxide

Greenhouse effect

Some atmospheric gases absorb Earth's outgoing emitted radiation and then re-emit some of it back through the atmosphere and eventually down to the surface

ozone hole

Chlorofluorocarbons (CFCs), manmade, eats ozone, created a large hole over the Antarctic, but it will recover

how to calculate the temperature at any given height in the atmosphere if you are given the environmental lapse rate

Rotation

The spinning of Earth on its axis, takes 24 hours to make one complete turn

Revolution

the movement of the Earth in an elliptical- not circular orbit around the sun, which takes 365 1/4 days

Solar elevation angle

SEA, angle the sun makes with horizon at any time, sun is on horizon, SEA is 0°, halfway up, SEA is 45°, directly overhead, SEA is 90°

solar noon angle

SNA, angle the sun makes with the horizon at solar noon, sun will be at its absolute highest point in the sky at solar noon on the first day of summer, absolute lowest point in the sky at solar noon on the first day of winter

How to find the solar noon angle anywhere at anytime using Analemma

Find the solar declination (SD)?

Calculate latitude difference to the SD

Subtract this difference from 90°

solar noon

the time when the sun reaches its highest point the sky, halfway between sunrise and sunset

solar declination

the latitude where sun is directly overhead at solar noon, sun cannot be 90° above the horizon unless you are within 23 1/2° latitude of the Equator

how to use the Analemma to find solar declination?

Aphelion

Earth is farthest from the sun, 152 million km, July 4

Perihelion

Earth is closet to the sun, 147 million km, Jan 3

Tilt of the Earth, how does this cause the seasons?

As the Earth travels around the Sun, the hemisphere that is tilted towards or away from the Sun changes. hemisphere that is tilted towards the Sun is warmer because sunlight travels more directly to the Earth's surface so less gets scattered in the atmosphere

Longest day of the year in Northern Hemisphere

June Solstice June 20-22

Shortest day of the year in the Northern Hemisphere

December Solstice December 20-22, north pole is tilted furthest from the sun

Longest day of the year in the Southern Hemisphere

Summer solstice December 22

Shortest day of the year in the Southern Hemisphere

Winter Solstice June 21

Land of the Midnight Sun

tilt allows 24 hours of Daylight (Darkness) at the Poles, anywhere poleward of the Arctic or Antarctic Circle in "their" summer

Astronomical Seasons in Northern Hemisphere

Spring March 21/22 to June 21/22

Summer June 21/22 to Sept 22/23

Autumn Sept 22/23 to Dec 21/22

Winter Dec 21/22 to March 21/22

Climatological Season in Northern Hemisphere

Spring March, April, May

Summer June, July, August

Autumn September, October, November

Winter December, January, February

4 Climatological Seasons

Temp 1st day of spring to summer increasing, 1st half of summer, temp are increasing then 2nd half temp decreasing. Temp 1st day of fall to winter temp decreasing, 1st half of winter temp decreasing, 2nd half of winter temp increasing

Kinetic Energy

energy due to motion, motion can be translational and/or vibrational, molecules or atoms moving from one place to another and/or just vibrating at a single location

Kinetic Energy with Temperature

the AVERAGE kinetic energy of atoms or molecules in a substance, moving fast=hot, moving slow=cold, as temperature increases, the amount of radiation emitted increases

Kinetic Energy with Heat

the TOTAL kinetic energy of atoms or molecules, Heat is the transfer of energy from warmer objects to cooler ones

Fahrenheit scale

1714, Gabriel Fahrenheit, mix of ice, water, and ammonium chloride always

Celsius scale

1742 Anders Celsius, uses freezing point 0, boiling point 100

Kelvin Scale

Absolute scale, no negative numbers since molecular motion ceases at 0K

Fahrenheit

(°Cx1.8)+32

Celcius

(°F-32)/1.8

Kelvin

°C+273.15

Latent Heat

Thermal energy that is released or absorbed by water when it undergoes a phase change

Evaporation

Liquid to gas, liquid water absorbs energy from atmosphere making air temp decreases, some water molecules get enough absorbed energy to escape their liquid prison, liquid water left behind loses energy and thus cools

Condensation

Gas to liquid, water gas releases energy into atmosphere, with less energy allows water vapor to return to liquid phase,

Different Types of Radiation from short to long waves

gamma rays, x-rays, ultraviolet, infrared, microwave, radio waves, longwave, All radiation at all wavelengths travels at the speed of light

conduction

heat transfer by contact, relatively slow process in air, not a good way heating the atmosphere because air is a lousy conductor of heat

convection

heat transferred due to the movement of a substance from one place to another, much more efficient than conduction (convection vertical air motions, advection horizontal air motions)

radiation

Energy that is radiated or transmitted in the form of rays or waves or particles, only way heat can be transferred in a vacuum

Stefan-Boltzmann Law

Hotter objects radiate more total energy than colder ones, the cooler the object the longer the wavelengths

Wien's Displacement Law

The wavelength of peak emission from a black body is inversely proportional to the absolute (kelvin) temperature of the body.

Radiation laws

-all objects above absolute zero, continually radiate energy at all wavelengths

-although all objects emit all wavelengths some wavelengths are emitted at small intensity

-there is one wavelength that an object will emit most of its radiation

-wavelength depends of the object's temperature

Absorption

-If absorption > emission, object heats up

-If absorption < emission, object cools down

-gas molecules are picky about which type of radiation they will absorb

-Some will only eat shortwave radiation (Shortwave < 1.4 μm)

-Some will only eat longwave radiation (longwave > 1.4 μm)

-some will eat both

-objects that are poor absorbers of visible light are light in color

Blackbodies

objects that absorb all wavelengths of radiation ie. black asphalt

Transmission

radiation passing through air molecules without interacting with any of them, about 55% of incoming solar radiation is transmitted

Reflection

radiation that bounces back from an object at the same angle it strikes the object and it bounces back at the same intensity

Scattering

produces a large number of rays traveling in all different directions, scattered rays are weaker than what hit the object

Albedo

percentage of radiation reflected by an object, earth's 30%, moon's 12%

why is the sky blue during the day?

gases in the atmosphere scatter solar radiation preferentially, atmospheric gases scatter blue+violet more effectively than reds+oranges, blue is at higher intensity level

Daily Mean

average of the 24 hourly temperature, add high and low temperature and divide by two

Daily Temperature Range

Difference between daily highs and lows

Monthly Mean

average of the daily mean for the month

Annual mean

average of the 12 monthly means for any given year

Annual Temperature Range

difference between highest and lowest MONTHLY mean

why is it always colder at the poles than the equator?

Due to the Spherical Earth. sun rays strike at a low angle near poles, high angle near equoter

Variations in temperature

#1 factor: amount of solar radiation received is never the same. solar angle, length of daylight

Controls of Temperature

-latitude

-Differential heating of land and water

-Geographic position (coast, inland)

-Ocean current

-Altitude

-Cloud cover

-Albedo variations