Test 9, Chapters 7-9 Flashcards
An electron stream that jerkily travels from a cloud during a thunderstorm
stepped leader
what forms the brilliant flash of a lightning bolt
return stroke
drops of liquid water that have a diameter of less than 0.5 millimeter and fall from clouds to Earth
drizzle
atmospheric pressure at sea level is ___ pounds per square inch
14.7
measures high-altitude weather conditions
weather balloon
which type of front forms when two air masses push against each other but neither one advances?
stationary front
the change in the direction of winds caused by Earth’s rotation is the ____ effect
Coriolis
which type of clouds are thunderstorm clouds?
cumulonimbus
what things affect insolation?
angle of sun’s rays; cloud cover; length of daytime
a tropical cyclone with wind speeds of 74 mph or more
hurricane
a wind that reverses its direction from season to season
monsoon
the thunderstorm stage marked by the arrival of precipitation
mature
what is a large, rotating updraft in a supercell thunderstorm?
mesocyclone
when the relative humidity is 100%, the air is
saturated
the water that falls to the earth, including rain, sleet, hail, and snow, is
precipitation
what phenomenon occurs when an area receives an abnormally low amount of atmospheric water over a long period
drought
which air mas brings hot, dry weather?
continental tropical
what is water vapor in the air that touches the cooler ground and turns to a liquid?
dew
what are the factors that determine the earth’s weather?
water vapor, heat energy, uneven distribution of heat energy
a tropical cyclone with wind speeds between 39 miles per hour and 74 miles per hour
tropical storm
a fierce, single-updraft thunderstorm
supercell
a narrow funnel of powerful, rapidly whirling wind that stretches from a cloud to the ground
tornado
the farthest distance at which objects can be distinguished
visibility
the elevated water level caused by a hurricane’s winds
storm surge
the most intense type of downburst
microburst
the shock wave produced as lightening heats the air
thunder
the outermost layer of the atmosphere
exosphere
boundary between 2 air masses
front
most abundant gas in the homosphere
nitrogen
heat transfer by electromagnetic waves
radiation
which type of cloud is characteristically almond shaped
lenticular
which type of ultraviolet radiation is the least harmful
UVA
surface winds that blow from high-pressure regions toward the equator
trade winds
the convection cell that exists between the equator and latitude 30 degrees
Hadley cell
a thick, brownish haze that results from complex molecules released into the air by vehicles and some factories and plants
photochemical smog
the boundary formed when a cold air mass moves into the territory of a warm air mass
cold front
what is the coldest point in the atmosphere
mesopause
what is the movement of water from the earth’s surface, into the air, and back to the surface?
water cycle
in clouds with temperatures above the freezing point, rain forms by the _________ process
collision-coalescence
the extremely powerful radiation that comes from deep space
cosmic rays
air flowing down a mountain’s slope due to a differences in temperature and pressure
katabatic wind
a circulating spiral of wind around a low-pressure system
cyclone
tornadoes are classified using the Enhanced ____ scale
Fujita
hurricanes are ranked on the ____ Hurricane Wind scale
Saffir-Simpson
the rapidly swirling cloud that is the most distinctive visual feature of a tornado is a
condensation funnel
a single updraft system in a thunderstorm is a
cell
air that is warm near the ground but very cold at higher altitudes is (stable or unstable)
unstable
“lines of equal heat” are known as
isotherms
maps that give a summary of the weather conditions throughout the entire country at a single point in time are
surface weather charts
a tornado that forms over water is called a
waterspout
the center of a hurricane is the
eye wall
a weather instrument that simultaneously measures and transmits meteorological data from weather balloons to weather stations is a
radiosonde
measures relative humidity
hygrometer
measures air temperature
thermometer
measures atmospheric pressure
barometer
measures wind speed
anemometer
uses radio waves to detect objects and measure their distance
radar
measures the amount of precipitation
rain gauge
indicates the direction of the wind
weather vane
measures the distance from the ground to the base of clouds
ceilometer
a rotating column of air that starts on the ground and is not associated with a cloud
dust devil
limes of equal pressure on a weather map
isobars
a long line of advancing thunderstorms, usually moving ahead of a cold front
squall line
a concentrated downward blast of wind
downburst
a localized storm involving lightning, thunder, strong winds, and heavy rain
thunderstorm
the long, narrow lines of thunderstorms in a hurricane
rain bands
state of the atmosphere at a certain time and place
weather
an abrupt discharge of electricity through the air
lightning
