GEOG 15.01 Midterm Vocab
Evapotranspiration
Sum of evaporation from bodies of water and transpiration from plants
Lifting Condensation Level
when temperature = dew point and condensation begins
Cloud Formation
Air parcel lifts and warms, condenses onto condensation nuclei, forms clouds
Mie Scattering
Mostly forward scattering, all lengths of light, so on cloudy days the sky is gray
Hydrologic Cycle
Movement of water through the Earth-Atmosphere system
Pressure
Pressure decreases exponentially as altitude increases
Adiabatic Process
Process of cooling where no heat is transferred within system
Net radiation surplus and deficit
Radiation absorbed from atmosphere and reflected from surface
Outgoing Longwave Radiation
Radiation emitted by the Earth's surface
Visible Light
Radiation that can be seen with the naked eye, Red=longest wavelength; Violet=shortest wavelength
Environmental Lapse Rate
Rate at which the air surrounding a parcel cools
Dry Adiabatic Lapse Rate
Rate at which the temperature of a parcel of dry air decreases as it is lifted, 1 deg C/1000m
Redness of sunsets
Rayleigh scattering, radiation has longer distances to travel to be scattered, molecules reflect red light
Water Vapor
Variable gas, important in cloud formation, radiation absorption, precipitation processes
Carbon Dioxide
Variable gas, important in radiation absorption and reflection, anthropogenic greenhouse gas
Clausius-Clapeyron relationship
Warmer air masses can hold more water vapor, will exacerbate extreme weather events
Saturated Adiabatic Lapse Rate
Rate at which saturated air cools, 0.5 deg C/1000m
Albedo
Ability of a surface to reflect radiation, affects temperature
Vapor pressure
Total atmospheric pressure due to water vapor
Ozone
A pollutant at the surface, important absorber of UV in stratosphere
Shortwave Radiation Incident
Amount of shortwave from atmosphere
Shortwave Radiation Absorbed
Amount of shortwave radiation received at surface from atmosphere
Humidity
Amount of water vapor in the air
Relative Humidity
Amount of water vapor in the air related to the maximum possible amount at the current temperature
Weather
Atmosphere phenomena on a timescale of minutes to months
Atmospheric Absorption
Atmospheric absorption of radiation depletes the amount that reaches the Earth's surface
Climate
Atmospheric patterns on a timescale of months to millenia
500 mb height
Average air temperature in vertical air column between surface and 6.0km above sea level
Beam Spreading
Beam of radiation covers larger area at smaller angle, intensity of radiation decreases with angle at which beam hits surface
Earth's rotation
Causes day and night and fluctuations in insolation
Frontal Lifting
Collision of warm and cool air fronts, warm air forced upward, adiabatic cooling and cloud formation
Net Radiation
Difference between incoming and outgoing radiation between Earth and Atmosphere
Conduction
Direct transfer of heat from one substance to another, causes temperature gradient above surface in laminar layer
Earth's Revolution
Distance from the sun does not effect seasons
Zero-Dimensional Climate Model
Earth is a uniform surface with no differences in latitude of longitude, and an equilibrium between incoming shortwave and outgoing longwave radiation
Global Energy Budget
Earth's balance of longwave and shortwave net radiation
Rayleigh Scattering
Forward and backward, performed by individual gas molecules, affects shorter (blue) wavelengths, responsible for blue skies
Electromagnetic Spectrum
Frequencies and wavelengths of radiation
Permanent Gases
Gases found everywhere in homosphere in relatively constant proportions
Variable Gases
Gases whose distributions in atmosphere is uneven in both space and time
Hydrostatic Equilibrium
Gravitational force is equal to vertical pressure gradient force
Updrafts of air
Gravitational force<vertical pressure gradient force
Downward motions of air
Gravitational force>vertical pressure gradient force
Horizontal Pressure Gradient
Greater pressure exerted on one region of air pushes air into zone of lower pressure, causes wind
Bergeron Process
Growth of ice crystals by evaporation of supercooled water
Riming
Growth of ice crystals through collision with supercooled droplets
Greenhouse Effect
Heat is trapped in Earth's atmosphere by carbon dioxide and other variable gases through repeated absorption and reflection
Level of free convection
Height to which a parcel of air must be lifted for it to become buoyant and rise on its own
Composition of Atmosphere
Homosphere and Heterosphere, Permanent and Variable gasses
Convergence
Horizontal movement of air at surface into another region of air forces air to rise because it cannot go down, adiabatic cooling, cloud formation
Stefan-Boltzmann Equation
Hotter objects radiate more energy than cool ones
Temperature Variations
How the temperature varies with season and region
Orographic Lifting
Lifting of air over a mountain and down sloping side which leads to adiabatic cooling and cloud formation
Troposphere
Lowest layer of Earth's atmosphere where all weather occurs
Density
No definite limit exists to the amount of mass that can fill a volume because air is compressible
Diurnal Temperature Cycle
Pattern of temperature change during the course of a day
Earth's tilt
Responsible for seasons, beam spreading, radiation depletion
Stratosphere
Second layer of Earth's atmosphere where the ozone layer resides
Ultraviolet Radiation
Shortest wavelength, dangerous to living things, absorbed by ozone in stratosphere
Aerosols
Solid particles or liquid droplets suspended in atmosphere important in cloud formation as condensation nuclei
Potential and Kinetic Energy
Stored energy and energy currently being used
Sensible Heat Flux
Surface heat and air above it
Saturation
The point at which the atmosphere can no longer hold water, condensation occurs
Vertical Pressure Gradient
The reduction of pressure with elevation, air closest to the surface is heaviest
Precipitation Formation
Through collision and coalescence, riming and aggregation, collector droplets, overcoming drag and gravity
Collision and Coalescence
Tiny cloud droplets collide and merge to form larger droplets
Thermal Infrared Radiation
Transfer of heat energy by electromagnetic waves
Vertical Structure of Atmosphere
Troposphere, Stratosphere, Mesosphere, Thermosphere
Convection
Uneven heating of air at the surface, air will rise, adiabatic cooling, cloud formation
Beam Depletion
Weakening of intensity as radiation travels through more atmosphere to reach surface
Nonselective scattering
absence of preference for any particular wavelength, clouds play a large role in reflection of energy back to space
Latent Heat Flux
energy required to change the phase of a substance
Condensation
gas to liquid
Evaporation
liquid to gas
Mixing ratio
mass of water vapor/mass of dry air
Atmospheric stability
susceptibility of air to uplift