Exam 1 Flashcards
Weather
Is the day to day variation in sky condition, temperature, precipitation, wind etc.
Climate
the distribution of a particular weather variable over a period of time (normally 30 years)
Troposphere*
the lowest layer of the atmosphere
- Contains our weather
Temperature
The average amount of heat energy present in a substance
Heat Energy
A measure of the kinetic energy of the molecules that make up a substance
Lapse Rate
the verticle change in temperature with height in the atmosphere
Closed System
Earth is a closed system where energy can move in/out but matter cannot
(barring extreme circumstances)
Open System
A leaf, you, a tractor etc. are open systems where both energy and matter can move in/out
Tropopause*
Occurs at the top of troposphere; defined by a change in lapse rate from negative to neutral or positive
(bounder between troposphere & stratosphere)
Energy*
The ability to do on some type of substance
(simply the ability to do work)
Work*
Done on a substance when its pushed, pulled, stretched, compressed, lifted etc.
Heat*
Energy in the process of being transferred from one object to another
Earth’s 4 Main Spheres
Geosphere
Atmosphere
Hydrosphere
Biosphere
Cryosphere
Cryosphere
Not a “main” sphere
Earth’s ice (glaciers, sea ice, Antarctica)
Geosphere
Solid Earth - makes up the vast majority of Earth’s mass
Rocks, minerals, landforms
Largest of the spheres
Atmosphere
Gaseous Envelope
Hydrosphere
All water
(solid, liquid, gas phases)
Biosphere
All life on earth
Dalton’s Law
If the air in a container is a mixture of gases, the total pressure equals the sum of the partial pressures of each individual gas
Ideal Gas Law
Relates pressure, volume, number of moles of a substance, a case constant and temperature
How does atmospheric pressure vary with altitude
Atmosphere is compressible
Hydrostatic balance determines how think our atmosphere is
How does heat flow?
Always flows from the hotter (more energetic) to the cooler (less energetic) object
Where does our weather come from?
Pressure and temperature gradients are fundamental energy sources in our atmosphere
Heat Capacity
Substances with large heat capacities change temperature more slowly than those small heat capacities
(larger the lake the later it will freeze)
Specific Heat
Amount of heat energy required to raise the temperature of 1 gram of a substance by 1°C
(water has the highest specific heat)
Sensible Heat
the heat energy that humans can feel and that can be measured with a thermometer
Latent Heat
Energy required to be absorbed/released to change a substance from one form to another
Without changing temperature*
(Putting energy into the ice without changing the temp but turning to water)
Conduction
Molecule to molecule transfer
(grabbing a hot pan with your hand)
Convection
Heat energy transferred by movement
Radiation
Transfer of heat by the movement of electromagnetic waves
Properties of Waves
Wavelength
Crest to crest distance
Properties of Waves
Amplitude
Height of wave
Properties of Waves
Frequency
Number of wavelengths per unit time (seconds)
Shortwave Radiation
Wavelength shorter than 3um
Visible, UV, X-rays
Emitted from the sun
Longwave Radiation
Wavelengths longer than 3um
Thermal, microwave, radar, radio waves
Emitted from Earth
What determines Short and Longwave Radiation
Temperature
Stefan Boltzmann Law
Gives the amount of radiation emitted by an object, based on its temperature
Greenhouse Gases
Gases in our atmosphere absorb long wave radiation well but do not absorb shortwave radiation very well or at all
Energy Losses in the Atmosphere
Transmitted
Scattered
Reflection
Absorption
Transmitted
Passes without interactions
Scattering
Energy sent in many directions
(smoke or dust in the air)
Reflection
Bounced off at an angel to incidence
Absorption
Absorbed by gases, particulates or ground (plant use)
Albedo
Ratio of the amount of energy reflected by a surface to the amount that is incident
(50% of the incident radiation is reflected)
Radiation Surplus
When more radiation comes in than goes out
Radiation Deficit
When less radiation comes in than goes out
Zenith Angle
Angle between directly overhead and the sun at solar noon
Sun Angle
Angle of the sun above horizon at solar noon
(between the sun & horizon)
Solar Declination
Latitude above which sun is directly overhead
Intertropical Convergence Zone (ITCZ)
Area of low level convergence that moves north and south about the equator with the seasons
Westerlies
Stronger flow to the north of the subtropical high
Mid-Latitude
Polar Easterlies
Poleward of 60°
Cold, high pressure winds turned to the east by the Coriolis Force as they move equator ward
Doldrums
Weak winds near equator
Tradewinds
Equatorward of 30°
Cooler, drier air moving towards equator
Horse Latitude
Weak winds near subtropical highs
Air Mass
Large body of air that has relatively uniform temperature and moisture characteristics
Polar Front
“Boundary” or transition region between polar and tropical air masses in mid-latitude
Jet Stream
“Currents” of fast moving air thousands of kilometers long and hundreds of kilometers wide but only a few kilometers thick
Polar Jet
Usually located between 30°N and 70°N depending on the season
(Occurs around the US & Canadian Boarder)
Subtropical Jet
Forms on poleward edge of Hadley cell at about 25°N
(Mainly a wintertime phenomenon)
Wind
Movement of air from one location to another
(Caused by differences in air pressure)
How does wind move
Always moves from high pressure to low pressure
Humidity
Amount of water vapor influences density
(Density decreases)
Cyclone
Low pressure system
(counterclockwise flow)
Anticyclone
High pressure system
(clockwise flow)
Trough
Elongated region of low pressure
(Low Jet stream)
Ridge
Elongated region of high pressure
(High jet stream)
Gravity
Force directed perpendicular to the Earth’s surface
Cold air pools/”drains” toward low spots in your fields, mountain, valleys
How does the wind blow with Pressure Gradient Force?
Blows from higher to lower pressure
Pressure Gradient
The change in pressure over distance
Coriolis Force
Apparent force that influences wind direction
What causes the Coriolis Force
A change in the total wind speed (Earth’s rotation + wind speed)
A change in the distance from Earth’s axis
Coriolis Force Summary
Always directed at right angles to direction of airflow
Affects wind direction
The stronger the wind, the greater deflecting Coriolis Force
Strongest at poles and nonexistent at equator
To the right in the N. hemisphere and to the leaf in the S. hemisphere
Friction
Resistant air movement, largely determined by how rough the Earth’s surface is
Planetary Boundary Layer
the lowest `1km of the atmosphere, directly affected by the surface through reduced wind speeds and presence of turbulence
Scales of Atmospheric Phenomena
Macroscale
Weeks or longer
Ex. Westerlies, Trade Winds
Scales of Atmospheric Phenomena
Synoptic
Days to Weeks
Ex. Mid latitude cyclones, anticyclones
Scales of Atmospheric Phenomena
Mesoscale
Minutes to Hours
Ex. Thunderstorms
Scales of Atmospheric Phenomena
Microscale
Seconds to Minutes
Ex. Gusts
Advection
Movement of air
(Cold air moving into a warm air)
Convergence
Air coming together
Divergence
Air going apart/away
Why do meteorologist use pressure surfaces as a preferred altitude coordinate
Weather moves along pressure surface
Pressure Surfaces
All pressure surfaces change height
What causes the difference in air pressure
Temperature
Horizontal Temperature Differences
High
Colder Temperature → Increased Density → Increased Pressure
Horizontal Temperature Differences
Low
Warmer Temperature → Decreased Density → Decreased Pressure
cP
Continental Polar
Forms over Canada and Alaska
mT
Maritime Tropical
From Gulf of Mexico, Caribbean Sea, Western Atlantic Ocean
Often Unstable
Responsible for much of the precipitation in central and eastern US
cT
Continental Tropical
Only source that affects US is in the desert southwest
Unstable but little moisture so few clouds and no precipitation
mP
Maritime Polar
From North Atlantic only rarely affects the northeast US
