210 likes | 359 Views
Weather Factors. Electromagnetic waves. A form of energy that can move through the vacuum of space. Radiation – the direct transfer of energy by electromagnetic waves. Non-Visible Radiation. Infrared radiation- wave lengths that are longer than red light (felt as heat)
E N D
Electromagnetic waves • A form of energy that can move through the vacuum of space. • Radiation – the direct transfer of energy by electromagnetic waves.
Non-Visible Radiation • Infrared radiation- wave lengths that are longer than red light (felt as heat) • Ultraviolet radiation- wavelengths shorter than violet light. (can cause sunburns, skin cancer and eye damage)
Energy in the Atmosphere • 25% of sunlight reflects off clouds • 20% absorbed by gases and particles in atmosphere • 5% reflected by surface back into atmosphere • 50% absorbed by Earth’s surface (some radiates back into atmosphere Only half of the sun’s energy reaches Earth’s surface
Why is the sky the color it is??? SCATTERING • DAY- gas molecules scatter short wavelengths of visible light (blue and violet) more than shorter wavelengths (orange and red). Scattered light looks bluer. • SUNRISE/SUNSET – light passes through greater thickness of atmosphere. Most blue end of spectrum is removed by scattering. Eyes see mostly red and orange light
Greenhouse effect • Gases act as a blanket and hold heat in the air. • Keeps Earth at a temperature that is comfortable for most living things.
Heat Transfer • Temperature – the average amount of energy of motion of each particle of a substance (how hot or cold something is) • Thermal energy- the total energy of motion in the particles of a substance • Hot tea in a pot has more thermal energy than hot tea in a cup because it has more particles.
How heat is transferred • Conduction – direct transfer of heat from one substance to another through touching • Convection – transfer of heat by movement of a fluid (liquid or gas) • Radiation- transfer of heat through empty space ( infrared rays)
What is wind?? • Horizontal movement of air from an area of high pressure to an area of low pressure • Anemometer – measures wind speed • Wind chill factor - increased cooling a wind can cause
Local winds • Caused by unequal heating of Earth’s surface within a small area • Sea breeze Land breeze
Coriolis Effect • The way Earth’s rotation makes winds curve • Global winds • Northern Hemisphere curve right • Southern Hemisphere curve left
Humidity – measure of the amount of water vapor in the air • Warm air can hold more water vapor than cool air • Relative humidity – is the percentage of water vapor that is actually in the air compared to the maximum amount if water vapor the air can hold at a given temperature • 10°C – 1 cubic meter of air can hold 8g of water vapor • If has 8g of water vapor – saturated or 100% relative humidity • If has 4g of water vapor – relative humidity is half or 50% • 100% = precipitation • Psychrometer- instrument that measures relative humidity
Evaporation –the process by which water molecules in liquid escape into the air • Condensation- molecules of water vapor in the air become liquid water • Dew point – the temperature at which condensation begins
Precipitationany form of water that falls from clouds and reaches Earth’s surface Rain gauge – an open-ended can or tube that collects rainfall About 10 inches of snow = 1 inch of rain
Drought – long periods of unusually low precipitation • Cloud seeding- a method to modify precipitation by dropping tiny crystals into clouds • Silver oxide and dry ice sprinkled into clouds • Water vapor condenses on the particles forming rain or snow • Not very effective in producing precipitation