Welcome Back Write down the 4 layers of the atmosphere (in order) and 1 fact about each.

Today’s agenda Finish ozone reading Review atmosphere Radiation, reflection, and absorption notes Lab

Atmosphere Layer of gases that surround Earth – 78% N – 21% 0 – 1% other Has a weight = atmospheric pressure 4 layers of the atmosphere

Radiation

Not that kind of Radiation All of the energy that Earth receives from the sun travels through space between Earth and the sun as radiation Radiation – transfer of thermal energy from the sun in the form of waves Radiation travels through space in the form of waves at a very high speed—approximately 300,000 km/s

Atmosphere and Radiation Scattering - clouds, dust, water droplets, and molecules in the atmosphere disrupt the paths of radiation from the sun – reflect and bend rays This causes the rays to travel in all directions w/o changing their wavelength Causes sky to be blue and sunrise and sunset to appear red/orange

Reflection and Absorption The sun gets reflected or absorbed The amount of sun absorbed or reflected depends on several factors – color, texture, composition, volume, mass, angle The intensity and time exposed affect how much energy is absorbed or reflected

Absorption and Infrared Energy Radiation that is not reflected is absorbed – rocks, soil, water, and other surface materials Gas molecules also absorb these infrared rays – water vapor and carbon dioxide The absorption heats the lower atmosphere and keeps Earth’s surface much warmer than if there were no atmosphere

Greenhouse Effect greenhouse effect - warming of the surface and lower atmosphere of Earth when gases in the air absorb and reradiate radiation Earth’s atmosphere slows the escape of energy that radiates from Earth’s surface

Greenhouse Effect Illustrated

albedo -fraction of solar radiation reflected off the surface of an object SurfaceReflectedAbsorbed Dark Soil Desert Grass Forest Water (high angle Water (low angle) Snow

Temperature Variation Radiation from the sun does not heat Earth equally The temperature of the atmosphere in any region on Earth’s surface depends on several factors – latitude, surface features, and the time of year and day

Latitude Latitude is the primary factor that affects the amount of solar energy that reaches any point on Earth’s surface Because Earth is a sphere, the sun’s rays do not strike all areas at the same angle The energy that reaches the equator is more intense than the energy that strikes the poles – average temperatures are higher near the equator than near the poles

Temperature Variation Cont. Amount of water in the air affects the temperature of a region – Water vapor stores heat Land areas close to large bodies of water generally have more moderate temperatures Wind patterns in an area also affect temperature