Place these notes into your Meteorology notebook. Chapter 17 Notes Place these notes into your Meteorology notebook.

Scientists hypothesize that Earth’s early atmosphere was formed primarily of gases released by volcanic eruptions. The main gases in the lower atmosphere are nitrogen and oxygen. N2 @78%, & O2 @21%. The composition of Earth’s atmosphere remains fairly stable because Earth has an efficient recycling system.

The energy from the sun reaches Earth by radiation The energy from the sun reaches Earth by radiation. Radiation falls somewhere within the electromagnetic radiation scale. Conduction is a process that transfers radiation from one particle to another. The soles of your feet could be heated if you stand barefoot on a sun-warmed sidewalk. A measure of the average kinetic energy of the atoms in a substance is its temperature.

The Earth’s surfaces absorb about 50 % of the Sun’s radiation. The freezing point and boiling point of water on the Celsius scale are respectively 0º and 100º. The troposphere is the layer of the atmosphere in which almost all of Earth’s weather occurs. The basic reason why the temperature of Earth’s surface varies from place to place is because insolation heats Earth’s surface unequally.

The Earth receives the greatest amount of the Sun’s energy when the sun is at a 90º. On a sunny summer day, the rays of the sun are strongest at 12pm. The lower air cools most rapidly during a clear night. The latitudes near the equator receive almost vertical rays of sunlight all through the year. Continents are warmer than nearby ocean waters during the summer because ocean waters warm more slowly than land.

If a city and a forest are located in the same region, the forest would be cooler on a hot summer day due to the shade. Isotherms are lines on a map that connect places with the same temperature. Smog is primarily caused by car exhaust. A temperature inversion occurs when air at Earth’s surface is colder than air above. Ozone in the stratosphere is very important to living things because it absorbs ultraviolet radiation.

Refer to the diagram below, which shows an island in the ocean on a clear summer day at 3 P.M. Place an A in the land area that is absorbing the most energy and place a B in the area that is reflecting the most energy. B A

Essay #1 Why are the North and South Poles much colder than the equator? The North and South Poles are much colder than the equator because temperatures are lower at the poles because there is less radiation per unit of surface area at the poles than there is at the equator. At the equator, the sun’s rays hit the surface at a near vertical angle. As a result, the sun’s energy is more concentrated over a given area. At the poles, the sun’s energy is less concentrated over the same given area. Also, the ice and snow at the poles reflect sunlight back out to space. (Albedo)

Essay #2 In a middle latitude region, how do the angle of insolation and the temperature change over the course of one year? Over the course of one summer? Over the course of one day? In one year, the angle of insolation changes from near vertical during the summer to less vertical during the winter. Temperature is warmest in late summer and coolest in late winter. In one day, the sun’s rays are closest to vertical at noon. The temperature is warmest in the afternoon and coolest just before dawn.