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