the condition of earth's atmosphere at a particular time and place
atmosphere
the envelope of gases that surrounds the planet
ozone
a form of oxygen that has three oxygen atoms in each molecule
water vapor
water in the form of a gas
density
the amount of mass in a given volume
pressure
the force pushing on an area or surface
air pressure
the result of the weight of a column of air pushing down on an area
barometer
an instrument that is used to measure air pressure
mercury barometer
a glass tube open at the bottom end and partially filled with mercury; measures air pressure
aneroid barometer
an airtight metal chamber sensitive to changes in air pressure
altitude
elevation; distance above sea level; the average of the surface of the oceans
list three factors affecting air pressure
temperature, altitude, water vapor content
troposphere
the layer of the atmosphere in which Earth's weather occurs
What is the rate at which temperature decreases in the troposphere?
drops 6.5 degrees celsius for every kilometer in altitude
stratosphere
second layer of atmosphere; contains the ozone layer
Describe the temperature change in the stratosphere
Temperature begins very cold (-60 c) but warms with increasing altitude due to the ozone layer
mesosphere
middle layer of the atmosphere
What is a main characteristic of the mesosphere
protects earth's surface from being hit by most meteoroids.
Define: Thermosphere
outermost layer; has no definate outer limit; thermo- means heat
Describe the Ionosphere
lower part of the thermosphere; engery from sun causes gas molucules to become electrically charge particles called ions; auroras occur; radio waves bounce here
Science Vocab 147928
