1. Weather / Meteorology Atmospheric Layers &Temperature

2. Atmospheric (air) pressure: the force, or weight, of the air pushing down on a unit area of surface. Conduction: the transfer of heat from molecule to molecule. Convection: the transfer of heat energy by currents. Dew Point: the temperature at which condensation occurs. Interface: the boundary between regions having different properties. Isobar: an isoline that connects points of equal atmospheric pressure on a weather map. Isotherm: an isoline that connects points of equal temperature on a weather map. Meteorology: the study of weather. Precipitation: (1) the falling of liquid or solid water from clouds; (2) the process by which dissolved substances come out of solution to form solids.

3. Earth’s Atmospheric Layers and Interfaces (p. 14 ESRT) Earth is surrounded by a shell of gases called the atmosphere. Graphs representing temperature, atmospheric (air) pressure, and water vapor concentration are shown on p. 14 ESRT. The atmosphere is separated into four different layers. Moving upwards from Earth’s surface is the troposphere, stratosphere, mesosphere, and the thermosphere. The different layers are separated from each other at interfaces (boundaries) called “pauses”. –The tropopause separates the troposphere and the stratosphere –The stratopause separates the stratosphere and the mesosphere –The mesopause separates the mesosphere and the thermosphere The y-axis represents altitude (height above sea level) and is marked in both km and mi. Make sure you are looking at the correct unit scale for each question! –The altitude of the tropopause is about 12 km or 8 mi high –The altitude of the stratopause is about 50 km or 31 mi high –The altitude of the mesopause is about 80 km or 50 mi high

4. Earth’s Atmospheric Layers (p. 14 ESRT) The y-axis represents altitude (height above sea level) and is marked in both km and mi. Make sure you are looking at the correct unit scale for each question! The Temperature Zones graph has temperatures ranging from -100°C to 100°C marked on the x-axis. Moving upwards from Earth’s surface the air temperature: –decreases in the troposphere, then –increases in the stratosphere, then –decreases in the mesosphere, then –increases in the thermosphere The Atmospheric Pressure graph represents air pressures ranging from 1.0 atm at Earth’s surface to close to 0 atm in the thermosphere. Therefore, as altitude increases, atmospheric (air) pressure decreases. The Water Vapor graph represents concentration of water vapor in g/m³. The water vapor concentration ranges from about 40 g/m³ at Earth’s surface to about 0 g/m³ in the lower stratosphere. Therefore, as altitude increases, water vapor concentration decreases.

5. Chemical Composition of the Troposphere (p. 1 ESRT) The chemical composition of the Earth’s crust (also called the lithosphere), hydrosphere (water at Earth’s surface), and troposphere (the lowest layer of earth’s atmosphere) can be found on p. 1 ESRT. Data for the hydrosphere and troposphere is given as a percentage by volume. Data for the crust is given as percentage by mass and by volume. What is the most abundant element in the troposphere? –Nitrogen

6. Heat Energy The atmosphere’s main source of heat energy is the sun. The word INSOLATION (INcoming SOLar radiATION) represents energy from the sun. Additionally, the atmosphere is heated by: –Conduction - heat moves from Earth’s surface to the atmosphere when air touches Earth’s heated surface. –Coriolis Effect – Earth’s rotation causes friction between Earth’s surface and atmosphere –Phase changes – when water changes from solid to liquid to gas and back heat energy is absorbed or released. (p.1 ESRT) Energy is transferred throughout the atmosphere through the process of convection or convection currents. Heat rises and cool sinks!

7. Temperature Temperature in the U.S. is generally measured in °F (Fahrenheit) but can also be measured in °C (Celsius) or K (Kelvin). This scale is on p. 13 ESRT Each line on the Fahrenheit scale is worth 2 °F. Each line on the Celsius scale is worth 1 °C. Each line on the Kelvin scale is worth 1 K. 30 °C = 86 °F 330 K = 57 °C

8. Temperature Patterns on Earth Isotherms are isolines that connect points of equal temperature. Isotherms should never touch or intersect. In general, warmer temperatures are found near the equator and cooler temperatures are found near the poles. Maps of the U.S. will generally have a semi-parallel pattern representing cooler temperatures to the north and warmer temperatures to the south. Draw isotherms using a 10°F interval on the map below:

9. Your work should look similar to this:

10. Orographic Effect (Mountain Barrier Effect) Using the Selected properties of Earth’s Atmosphere Chart (p.14 ESRT) we see that as altitude increases, air pressure decreases. (There is greater air pressure at Earth’s surface than there is higher up in the atmosphere) As air moves up and over a mountain changes occur to the air pressure and temperature. As air moves up one side of the mountain (the WINDWARD side) the following occurs: –Rising air has less pressure on it so it expands. –As air expands, the molecules have more space around and they bump into each other less often (less molecular collisions) –Less molecular collisions result in less heat transfer and the temperature drops. –As the temperature cools, condensation occurs resulting in greater humidity (moisture in the air) and clouds and precipitation (rain, snow) form. On the other side of the mountain (the LEEWARD side) the air moves back down towards Earth’s surface and the following changes occur: –Sinking air has more pressure on it so the air is compressed –As air is compressed, more molecular collisions occur –More molecular collisions cause temperatures to warm –Warmer air results in evaporation, not condensation, and the air becomes more arid (dry)

11. Orographic Effect (Mountain Barrier Effect) Summary WINDWARD SIDE air rises ↓ pressure decreases ↓ less molecular collisions ↓ less heat (cooler) ↓ condensation results in clouds and rain (humid) LEEWARD SIDE air sinks ↓ pressure increases ↓ more molecular collisions ↓ more heat (warmer) ↓ evaporation results in a drier (arid) climate