Download Atmosphere and Weather: Ch. 3 Atmosphere Review Weather

Atmosphere and Weather: Ch. 3 Atmosphere Review
WEATHER is the condition of Earth’s atmosphere at a particular time and PLACE. Earth’s ATMOSPHERE is
the envelope of GASES that surrounds the planet. It consists mostly of NITROGEN (78%) and OXYGEN
(21%). Carbon Dioxide, WATER VAPOR, other gases and even particles of SOLIDS and liquids are also
considered part of the atmosphere.
Most air contains WATER VAPOR. Clouds form when water vapor CONDENSES out of the air to form tiny
droplets of RAIN or SNOW. If these droplets become heavy enough they will FALL to Earth.
Air has mass and VOLUME. This means that air has density and PRESSURE too. Air PRESSURE is the result
of the weight of a column of air pushing on an area. The reason air pressure does not crush you is
because the molecules in air push in ALL directions. So the air pushing up is BALANCED by the air pushing
down. Air pressure DECREASES as altitude increases, so does density.
Earth’s atmosphere can be divided into FOUR main layers. The TROPOSPHERE, STRATOSPHERE,
MESOSPHERE and THERMOSPHERE. The Troposphere contains most of Earth’s WEATHER. Next is the
STRATOSPHERE. It contains the OZONE layer. Third, is the Mesosphere. It protects Earth from being hit
by most METEORS. The outermost layer is the THERMOSPHERE. The INTERNATIONAL SPACE STATION and
other low Earth orbit satellites are found here.
Most of the energy from the Sun travels to Earth as RADIATION. Some sunlight is absorbed or REFLECTED
by our atmosphere before it can reach the surface. The rest passes THROUGH the atmosphere to reach
the surface. Earth’s surface radiates some energy back into the atmosphere as heat. Some of this heat is
trapped in the atmosphere by GREENHOUSE GASES like Carbon Dioxide. This is called the GREENHOUSE
EFFECT and keeps our planet at a comfortable temperature. Scientist have evidence that HUMAN
activities are altering this process and Earth is experiencing GLOBAL WARMING.
Radiation, conduction and convection work together to HEAT the Troposphere. Heat in Earth’s
atmosphere is transferred mostly by CONVECTION currents within the Troposphere. The rising and falling
of AIR masses moves heat around and forms weather.
Differences in AIR PRESSURE cause the air to move. A WIND is the movement of air parallel to Earth’s
surface. It can be described by speed and DIRECTION. Most differences in air pressure are caused by the
unequal heating of the EARTH’S ATMOSPHERE.
Word Wall:
Weather, atmosphere, water vapor, density, air pressure, barometer,
altitude, troposphere, stratosphere, mesosphere, thermosphere, ionosphere,
exosphere, electromagnetic waves, radiation, infrared radiation, ultra violet
radiation, greenhouse effect, temperature, thermometer, heat, convection,
conduction, convection currents, wind, anemometer, local winds, mountain
breeze, valley breeze, global winds
Sample Question: The transfer of energy by the movement of a fluid is called ____________________.