N. Hemi- 60% Water, 40% Land

Meteorology

Land Vs. Water

N. Hemi- 60% Water, 40% Land

S. Hemi- 81% Water, 19% Land

• Water heats up and cools down slowly-specific heat
• N. hemi has higher highs and lower lows than s. hemi

Composition and Evolution of our ATM

78%N

21%O

Traces of: S, Ar(other noble gasses), CH4, CO2, H2O

Sources of our ATM:

Volcanoes- SO2, CH4

Meteorites

Lightning

Erosion

Mauna Loa Graph-

x-axis= time

y-axis= CO2 concentration in ppm

Shows: steady and ever increasing slope

Yearly jogs in slope indicate seasons. Peak per year = fall and Valley per year = spring.

Aerosols- suspended fine(small) particles in the ATM. Solid particles dissolved in air that are too small to see, but can get in your body.

React with other gasses to make a hole in our ozone layer(CFC’s) and acid rain(Sulfur).

Can affect climate by affecting cloud formation(they help make clouds) and reflecting sunlight. Sources of Aerosols:

Volcanoes, Dust Storms, Forest/Grass Fires, All Fossil Fuels Burning, Factories, Dead Skin Cells, Space Dust

Hydrologic(water) Cycle- no start/stop, but continuous procedure where water changes forms and places, but is never lost or gained.

Condensation: gas to liquid(clouds)

Precipitation: H20 back to earth

Evaporation: liquid to gas

Transpiration: evap. from plants

Also includes sinks(places where it looks like water is removed from the cycle): ocean, groundwater, the rock cycle, glaciers

Hydrologic Cycle- describes the continuous motion of water above and below the surface(powered by the sun)

Evaporation- water transported from the surface to the ATM(liquid to gas). Affected by temp, humidity, amount of moisture available.

Condensation(vaporization)- transfer of H2O from gas to liquid. Affected by temperature and amount of moisture available. Condensation creates clouds.

Precipitation- buildup of moisture in cloud. Transfer of water from ATM to ground.

Transpiration- water evaporates from the leaves of plants

Pressure Vs. Altitude:

Air gets thinner when you go higher. It’s going to weigh things down. For every height increase there is less air on top of you. As the air on top of you decreases the air will expand.

Air pressure decreases with altitude.

Layers of the atmosphere

In the troposphere the temp goes down

The top of the mesosphere is 80 km In the mesosphere the temperature decreases this is where the meteors get burned.

The thermosphere the shuttles fly here and the temps go up.

at 10,000ft, pressure is 65% sea level. At 30,000ft(top of Mt. Everest) there is less than 30% air pressure left. As you leave the earth, there is less ATM above, so there is less pressure, which allows air to expand. The decrease in pressure with height forces the temp to drop.

Troposphere is 80% mass of the atmosphere (0-10km). All earth’s weather is in the troposphere. Stratosphere (10-30km) has the ozone layer. Planes fly here. The temperature increases. Mesosphere (30-55km) is where meteors get burned. The temperature decreases. Thermosphere (up to 160km) Space shuttles fly here. Temps increase here. Exosphere (55-120km) is the boundary of earth/space.

Heat: form of energy, can transfer between objects

Parcel of air: imaginary volume of air used in meteorology to explain the ATM.

Temperature: degree of “hotness” or “coldness” of an environment- measure of the average kinetic(moving particles)energy. (what we feel as hot or cold)

Temperature scales:

Fahrenheit- Boiling Pt = 212FFreezing Pt= 32F Absolute Zero= -460F Most of Life is Spent Between 100F and 0F

Celsius- boiling point of water= 100C

Freezing point = 0 C. absolute zero = -273 C Most of Life is Spent Between 35C and -10C

Kelvin- boiling point= 373 K freezing point= 273 K. absolute zero = 0 K. Most of Life is Spent Between 263K and 310K.

Specific heat: The amount of heat required to raise one gram of a substance by 1 C.

Low specific heat = rocks, sand, pavement

High specific heat = air, water, liquids

Convection: transfer of heat in a vertical direction. Form of heat transfer, works in a vertical direction. Hot material rises and cool material falls.

Sensible heat- a change in the temperature because of a change in energy.

Conduction- transfer of heat between molecules that are touching.

Examples: metal, soil,

Poor conductors: water, air,

Radiation- transfer of energy through waves/particles through space.

Advection- transfer of energy that works horizontally.Caused by pressure differences which are caused by temperature which are caused by unequal heating of the earth.

Adiabatic cooling- cooling of a parcel of air as it rises. As air rises there is less pressure on it so it expands, reduces air pressure and cools.

Lapse Rate: The rate of decrease of temp with height equals 10C/ 1000m for dry air. Lapse rate equals 6c per 1000m for moist air.

Stefan- Boltzmann Law: E = T4 hot objects emit a lot more energy then cool objects.

Wien’s Law: objects of different temperatures emit different color light. Hot objects emit short wave length light. Short wave length light has high energy

The Seasons:

Are based on the 23.5 degree tilt of Earth’s axis. During the s-hemi summer the s-hemi receives 3X the light of the n-hemi.

Vernal equinox:

Late March marks the beginning of Spring.

Autumnal equinox:

Begins late September and marks the beginning of Fall.

Solstices:

Winter (late December) = start of winter, Summer (June) = start of summer (apogee)

Atmospheric Window:

Wave lengths of light that go through the atmosphere. There is a window for: IR, sunlight, and radio waves. There is no window for UV, X-rays, Gamna rays.

a parcel of air rising gets cooler. Air pressure decreases with alt. That causes a parcel of air to expand.

LAPSE rate- decrease in temp with height. When air is dry the lapse rate is 10c/1000m. When air moist the lapse rate is 6c/1000m. The dryer the air the steeper the lapse rate.

Diabatic cooling- is moist lapse rate.

Stefan-Boltzmann Law- E=T4- High temps= high E.

Wein’s Law= short wavelengths are emitted by hot objects

Albedo- reflectivity of a surface. High albedo= metal

Low albedo= rubber, black paper

The higher the albedo of a surface, the cooler it stays.

The Seasons

-earth orbits sun on tilted axis of 23.5 degrees

-earth does not receive sunlight evenly

-Summer = n. hemi. Tilted towards sun

- Winter = n. hemi. Tilted away from the sun

-Fall/Spring = both hemis. Receive equal light

-June 21st longest day in n. hemi. w/ most direct sunlight- summer solstice

-Dec. 21st shortest day in the n. hemi. w/ the least amount of sunlight- winter solstice

-Sept. 22nd autumnal/ fall equinox

-March 22nd vernal/ spring equinox

Atmospheric window- the wavelengths of light that can go through our atm.

No Window- x-ray, gamma, uv

Window – visible light, radio light, infrared (partial)

The Greenhouse Effect(GHE)

Rise in temperature because of gasses present in our ATM. The main gasses are CO2, methane, nitrous oxide, H2O. All of those gasses transmit sunlight(short wavelengths). All of these gasses absorb and then emit earthlight. With the GHE, earth’s average temp is 57F. without the GHE, earth’s temp would plummet to 0F. When people talk about the effect humans have, they are talking about global warming which includes the added anthropogenic GHG’s.

Chapter 3 Notes

$Temperature$

Daily Mean Temp- Average of the daily max and min. Temps

Annual temp cycle- Seasonal change in temps. Caused by tilt of earth

Annual mean temp- The average temp.for the year. Add up monthly means and divide by 12.

Temp range- Difference between max and min

Factors that effect daily (diurnal) temp range- Cloud cover/ Reduces range, Wind/Reduces range, Humidity/ Reduces range

Factors that effect yearly temp range-

1. Latitude

2. elevation

3. Being near water/sand

4. Persistent clouds

5. Surface type

6. Persistent Humidity

7. Aspect

Interannual Temp Changes(Global Climate Change)

 El Nino/ La Nina changes in the ocean temp.

 Volcanoes add chemicals to our atmosphere that blocks sunlight

 Glaciers make earths albedo go way up

 Sunspots make earth warmer

 Earths tilts various between 21-25 degrees. More equals colder

 Earths orbit flattens which makes earth colder

Carbon dioxide

Water temperature increases/climate would change

Glaciers melting-when they melt earths albedo decreases

El nino

Volcanoes-make the earth colder, by putting gases in the air that reflect sunlight

Earth’s tilt wabbles

Earth’s orbit gets more elliptical which makes the earth colder

Temperature Inversions:

Normal Conditions: Temperature Drops with Height

Inverted Conditions: Temperature Increases with Height

How?Why?Where?-occurs when less dense(warm) air moves over more dense air (cold)

Warm front-when the clouds are warmer than the ground

Cold front-cold air moves in at ground underneath warm air

Nocturnal inversion- the winter season especially October-March, longer nights earth cools faster than air

Just before daybreak is the most inverted air.

Valley inversion- cold air gets trapped between mountains

Lapse Rate- rate of decrease in temp with height. 10C/Km when dry. Will be less if humid.

Stable Air- actual lapse rate less than 10C. Air will not rise- no clouds

Unstable Air- actual lapse rate greater than 10C. Air will rise and form clouds.

Wind Chill- how much the wind makes the temp feel colder. Caused by blowing away the warm conducted air your body creates.

Farmers Vs. The Cold- 1-spray crops to freeze them because the latent heat of freezing is exothermic.

2- cover them with tarps

3- fans that mix the air

Chapter 4 Measuring Moisture in the Air

Mixing Ratio- ratio of mass of moisture in air vs. mass of dry air. This is an absolute value and does not depend on temp.

Saturation Vapor Pressure- pressure exerted by a gas on its container. Saturation means the most moisture air can hold before condensation occurs. Relative term because it depends on how cold/hot the air is. Cold air can’t hold much moisture, so a little bit of moisture is a high vapor pressure. Hot air can hold a ton of moisture, so the same little bit of moisture seems bone dry.

Evaporation- reverse of condensation- when water is turned to a gas.

Factors that affect evap rate:

1- sun/heat

2- wind

3- moisture already in air

4- amount of water

5- shape of water

Dew Pt- temp at which a given parcel of air must be cooled to to create condensation

Dew Pt Depression- difference between air temp and dew pt temp(always lower than air temp)

Lab Review-

Surface Area-What is the effect of surface area on evaporation rate?

More surface=more evaporation

Constant- ml of water, air pressure, air temp

Control- the least s.area

Temperature- What is the effect of temp on evaporation rate?

Hotter=more evap

Constant- amount of water, surface area

Control- coldest trial

Cloud Formation-

Come from evaporated water.

Must be higher than 50ft.

Have to have rising air that cools adiabatically.

Rising air cools to reach its dew pt and condenses into droplets.

Condensation Nuclei- smoke, pollen, pollution, dust. These particles provide a surface for the vapor to condense around.

Situations that help clouds to form(cause air to rise):

1- Recent Rain

2- Solar Energy(heat)

3- Mountains

4- Fronts(warm or cold)

Cloud Types-

Low- stratus(flat or layered), stratocumulus(puffy, tall), nimbo(rain)stratus(low, flat, raincloud)

Middle- alto(high)stratus(layered), cumulonimbus(puffy, tall raincloud), altocumulus(high, puffy- lower than a cirrus, but higher than a stratus)

High- cirrus(high, thin, icy), cirrocumulus(high, wispy, puff), cirrostratus(high, layered cloud)

Special Clouds- contrails- aircraft exhaust, lenticular- lens- form as wind goes past a mountain or hill, congestus- warm, moist air rising in cauliflower shapes

Precipitation Types

Liquid- rain- cloud temp(either above or below 32F)air temp(above 32F)ground temp(above 32F)

Freezing- freezing rain- cloud temp(usually below 32F)air temp(warmer than 32F)ground temp(below 32F)

Frozen- sleet- cloud temp(below32F) air temp(above 32F) ground temp(below 32F)A thicker layer of ATM is below 32F for sleet, therefore it is frozen before it hits the ground and makes a “tink” sound when it hits.

Snow-cloud(below 32F) air(below32F) ground(below 32F)

Hail- cloud(below 32F) air(above32F) ground(above 32F)- forms in the updraft of severe t-storms in the summer.

Nimbus(root)- raining

Cumulo(prefix), cumulus(root)- puffy, taller rather than wide

Alto(prefix)- high

Strato(prefix), stratus(root- layered, sheetlike

Cirro(prefix), Cirrus(root)- curly, wispy

Altostratus= high layered cloud

Cumulonimbus= puffy, raincloud

Cirrus= highest, wispy, icy

Stratocumulus= puffy, layered cloud

Cirrostratus= thin, wispy, layered(sundog- icy ring around sun)

Nimbostratus= raining, sheet cloud

Chapter 5 Weather Instruments

ASOS- automated surface observing system.

Resistance thermometer- temp is sensed by using predictable changes in the resistivity of a wire at different temps. (Pt)(Ni)

Alcohol thermometer- used to measure temps. From -115C-785C. Liquids are used because they expand and contract easily.

Rules for Placement of Thermometers-

-6ft above ground

-away from structures

-in the shade

Dew point hygrometer- an instrument that measures dew point by measuring the temp.at which water vapor condenses

Psychrometer- measures humidity by using two thermometers. One having a wet bulb (should be colder) and one having a dry bulb (should warmer)

Mercury barometer- an instrument that determines atmospheric pressure using liquid (Hg)

Aneroid barometer- measures air pressure by using thin metal which expands and contracts due to pressure changes

Anemometer- measures wind speed by using cups

Wind vane- measures wind direction

Wind sock- measures direction and speed

Rain gauge- measures liquid precipitation that falls

Radiosonde-

Weather Maps-

Ceilometer- measures the height of the lowest cloud. Can help determine precipitation type and amount.

Visibility Sensor- measures the presence, intensity and duration of fog. Give secondary info on precipitation rate.

GEO- Geostationary Earth Orbit(satellite)- Orbit earth exactly as fast as earth spins, so it appears in one spot. GEO’s orbit around the equator and are designed to track hurricanes. Orbit height is 35,000km or 20,000mi.

LEO- Low Earth Orbit- orbit at 850km or 500mi. Provide very clear pictures. Move around the earth so they provide information on more than one storm, but none for any length of time. Also, they orbit from pole to pole so they give info on winter storms.

Visible Satellite- provides a picture from space of how the earth and clouds would actually look from space. Useless at night.

Infrared Satellite- uses heat to show cloud height. Cold weather clouds(stratus) grow wide rather than tall and show up as warm clouds. Warm weather clouds(cumulus) grow tall rather than wide and show up as cold clouds.

Water Vapor Satellite- shows moisture as bright green and dry air as black and really dry as orange. Excellent because it clearly shows the general flow of airmasses.

RADAR- uses Radio Detection and Ranging to tell where precipitation is.

Doppler RADAR- uses the Doppler effect to measure speed of storms.

Wind Profiler- represents rotation among thunderstorms as signs of tornadoes.

Wind Chapter 6

Gravitational Force- force of attraction between all objects in the universe. The strength of the force is based on mass and distance. The earth pulls strongest on everything we see because we are VERY close to the center of the earth. The next strongest pull on objects is from the moon as seen by the tides. The next strongest gravitational pull is from the sun.

Pressure Gradient Force(PGF)- acceleration of air due to pressure

-Usually responsible for excelling a parcel of air from a high pressure to lower

-

CoriolisForce- Changes the direction but not the overall speed of anything moving with respect to the ground (including air)

-Apparent reflection of moving objects when they are viewed from a rotating reference frame.

-Objects deflect to the right in the northern hemisphere

-Objects deflect to the left in the southern hemisphere

-The amount of deflection the air makes is directly related to both the speed at which the air is moving and its latitude.

Frictional Force- caused by air flowing over a rough surface, reduces wind speed, works opposite the flow of wind

Surfaces with High Friction:

Mtn’s/Volcanoes

Bldg’s

Trees

Surfaces with Low Friction:

Water(ocean/lake)

Grassland(Neb/Iowa/Kansas)

Centrifugal Force- outward force associated with rotation- seen in meteorology as air flows from H to L pressure and is curved by coriolis

Hydrostatic Balance- balance between gravity and upward PGF caused by high pressured air at earth’s surface vs. low pressured air at altitude

Geostrophic Balance- wind that results from balance between PGF and Coriolis(basically, the wind we feel on earth)

Buys Ballot’s Law- Wind flows at right angle to PGF. Way of determining where low pressure is by putting back to wind and reaching out with left hand that will point to where storm is.

Gradient Balance- A more accurate method of determining the wind because it is a three way balance of Coriolis, PGF and centrifugal force. It is the wind you feel when you stand on Earth.

Guldberg-Mohn Balance- The three way balance of Coriolis, PGF and Friction. Because of friction wind flows across iso-bars.

Scales of Motion-

Microscale- smaller, 1 km or less, tornado

Mesoscale- 1km-100’s km, thunderstorms, fronts, sea/land breezes, snow storms, hurricanes

Synoptic- 100’skm-1000’s km, when the total cloud outflow surrounding a storm is included, it is synoptic scale