Natural Disasters Ch. 9

Adiabatic process

the change in temperature of a mass without adding or subtracting heat. examples are cooling with expansion & warming upon compression

Albedo

the reflectivity of a body; for Earth, how much solar radiation is reflected back to space

Anticyclone

a region of high atmospheric pressure & outflowing air that rotates clockwise in the Northern Hemisphere

Barometer

an instrument for measuring atmospheric pressure

Climate

the average weather conditions at a place over many years

Conduction

direct transfer of heat from one material to another

Convection

process of heat transfer whereby hotter air, water, or rock rises upward due to its lower density while cooler material above sinks because of its higher density

Coriolis effect

moving objects experience Earth move out from beneath them; in the Northern Hemisphere, bodies move toward their right-hand sides, while in the Southern Hemisphere, they move toward their left

Cyclone

a region of low atmospheric pressure and converging air that rotates counterclockwise in the Northern Hemisphere

Dew point temperature

the air temperature when the relative humidity of an air mass reaches 100% and excess water vapor condenses to liquid water

dielectric constant

a measure of the displacement currents occurring after applying an electric field

Ferrel cell

surface air flows toward the poles from about 30 degrees latitude until rising at the subpolar lows around 60 degrees latitude; a secondary air cell formed between the Hadley & Polar cells

Front

a boundary separating air masses of different temperature or moisture content

Greenhouse effect

the buildup of heat beneath substances such as glass, water vapor, & carbon dioxide that allow incoming, short-wavelength solar radiation to pass through, but block the return of long-wavelength radiation

Hadley cell

a thermally driven atmospheric circulation pattern whereby hoot air rises at the equator, divides & flows toward both poles, & then descends to the surface at about 30 degrees north & south latitude

Heat capacity

the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree celsius

Humidity

a measure of the amount of water vapor in an air mass

Hydrologic cycle

the solar-powered cycle in which water is evaporated from the oceans, dumped on the land as rain & snow, & pulled by gravity back to the oceans as glaciers, stream, & groundwater

Insolation

amount of solar radiation received at any area on Earth

Intertropical Convergence Zone (ITCZ)

the zone where collision occurs between the trade winds of the Northern & Southern hemispheres

Ion

an electrically charged atom or group of atoms

Isobar

a map line connecting points of equal pressure

Jet stream

fast-moving belts of air in the upper troposphere that flow toward the east

lapse rate

the rate at which Earth’s atmosphere cools with increasing altitude, or warms with decreasing altitude

Latent heat

the energy absorbed or released during a change of state

Latent heat of condensation

the heat released when vapor condenses to liquid. for water, the heat release is about 600 calories per gram

Latent heat of fusion

water releases about 80 calories per gram when it freezes. in reverse, ice absorbs about 80 calories per gram when it melts

Latent heat of vaporization

water absorbs about 600 calories per gram when it evaporates. this stored heat is released during condensation

Lifting condensation level

the altitude in the atmosphere where rising air cools to saturation (100% humidity) & condensation begins

Mesosphere

1) the mantle from the base of the asthenosphere to the top of the core

2) the atmospheric layer above the stratosphere & below the thermosphere

Monsoon

winds that reverse direction seasonally. in summer, warm air rises above hot land, drawing in rain-bearing winds from over the ocean. in winter, the flow reverses

Polar cell

cold, dense air over the poles flows along the surface to about 60 degrees latitude where it’s warm & moist enough to rise at the subpolar lows & flow back toward the poles at higher altitudes

Polar vortex

an upper-level mass of very cold air around both the North & South poles; they are strongest during winters

Pressure gradient force

perpendicular to the air pressure isobars on a map is a gradient or slope of pressure change. air flows from high to low pressure

Sensible heat

heat carried by conduction or convection in air, water, or rock

Solar radiation

energy emitted from the sun mostly in the infrared, visible light, and ultraviolet wavelengths

Specific heat

the amount of heat required to increase the temperature of 1 gram of a substance by 1 degree celsius

Stratosphere

the stable atmospheric layer above the troposphere

Sublimation

changing from solid to gas without passing through a liquid phase

Surface tension

the attractive force between molecules at a surface

Thermohaline flow

the flow of deep-ocean waters made denser by coldness (thermo) and saltiness (haline)

Tropopause

the top of the troposphere

Troposphere

the lowest layer of the atmosphere, ranging from 18km (11mi) thick at the equator to 8km (5mi) thick at the poles