Earth Science- Schwartz Chapter 17 Earth Science- Schwartz

Weather vs. climate Meteorology is the study of the atmosphere and the processes that cause what we refer to as “weather.” Climatology is the long-term study of the atmosphere and the processes that cause what we refer to as “climate.” Weather refers to the short-term phenomena. Climate refers to the long-term patterns.

The atmosphere The atmosphere is a mixture of gas molecules, small suspended particles of solid and liquid, and falling precipitation.

What is the atmosphere made up of? Nitrogen 78% Oxygen 21% Argon less than 1% CO2 less than 1%

What is the atmosphere made up of? Some of the atmosphere’s “ingredients” change based on location, time of year and pollutants. Water vapor is the source of all clouds and precipitation carbon dioxide, water vapor absorbs heat given off by Earth. It also absorbs some solar energy. Ozone is a form of oxygen that combines three oxygen atoms into each molecule (O3). ozone filters UV radiation in the stratosphere allowing life to exist as we know it, In troposphere ozone causes smog

ozone Ozone in the lower atmosphere (troposphere) = bad ozone filters UV radiation in the stratosphere allowing life to exist as we know it, Ozone in the lower atmosphere (troposphere) = bad Damages our lungs, damage to plants Ozone in the stratosphere = good Protects us! Warms us up

Other variable components of the atmosphere Human activity adds “stuff” into the atmosphere Primary pollutants = emitted directly from identifiable source Secondary pollutants = not emitted directly into air.- but are created as a result of a chemical reaction that has taken place in the atmosphere

Height and Structure of the Atmosphere There are 4 distinct layers of the atmosphere emerge from identifiable temperature characteristics with height. Pressure also changes with height

Pressure changes with height Atmospheric pressure is simply the weight of the air above. Air pressure decreases with altitude, because there is less Atmosphere pushing down the higher you go!

Temperature changes with height Troposphere bottom layer of the atmosphere temperature decreases with an increase in altitude. stratosphere 2nd layer temperature gradual increase because of ozone

Temperature changes with height mesosphere 3rd layer characterized by decreasing temperatures with height, contains no O3 thermosphere 4th layer characterized by increasing temperatures

Earth-Sun Relationship Earth has 2 main motions Rotation: spinning on axis (23.5o tilt) Revolution: movement of Earth in its orbit around the sun Seasonal changes occur b/c Earth’s position to the sun constantly changes as it travels along its orbit If the axis was NOT tilted we would not have seasonal changes Axis points to the North Star

The Causes of Earth’s Seasons Summer and Winter Solstices

The Causes of Earth’s Seasons Summer and Winter Solstices

The Causes of Earth’s Seasons Equinox: March 21 and September 21

Solstice Summer Solstice: 1st day of summer (NH leaning toward the sun) June 21 or 22 Winter Solstice: 1st day of winter (NH leaning away from the sun) December 21 or 22

Equinox Autumnal Equinox: Sept. 22 or 23 in NH (occurs halfway btw the solstice) Spring Equinox: March 21 or 22 in NH (axis neither leaning toward or away from the sun)

Length of day Length of daylight = Earth’s position in orbit Summer = longer daylight Animation