Solar Radiation (Electromagnetic and Atmospheric Energy) Created By: Mr. Kreeger
Homework and Page References • Page References • Page 478-480, 484-486, 491 • Homework • Explain in 2 to 3 sentences why shorter wavelength radiation is more harmful than longer wavelength radiation. • Do numbers 7-9 on page 486 • Do numbers 16 and 17 on page 493 • Draw the phase change diagram and label what is occurring at each section of the diagram (Project Grade- Due in 3 days) • COLLECT WEATHER DATA EVERY DAY
Table of Contents • Components and factors in the Atmosphere. • Electromagnetic Energy • Solar Energy • Visible Light • Matter and Electromagnetic Energy • Refraction • Scattering • Absorption • Earth’s Energy • Energy Transfer in the Atmosphere • Conduction • Convection • Radiation • Heat and temperature • Temp • Temp Scales • Heat • Calories • Specific Heat • Heat energy and phase changes • Latent Heat • Adding heat • Losing heat • Water and latent heat
Components and factors in the Atmosphere • Weather is the state or Condition of the atmosphere at a particular time • Meteorology is the study of weather • Atmospheric variables are changes in weather such as temp, air pressure, moisture, precip., wind speed and cloud cover
Electromagnetic Energy • All EM energy travels through space at speed of light. • Shorter wavelengths greater frequency (More Harmful) • Longer wavelengths shorter frequency (less harmful)
Solar Energy • Energy from sun major source of energy for earth, sun produces all frequencies of energy. • Visible Light- Small area of EM spectrum (4.0*10^-5—7.0*10^-5), greatest intensity of all EM energy.
Matter and Electromagnetic Energy • When EM energy hits materials it can be • Refracted-Bent • Scattered- Reflected and Refracted • Absorbed • Any material that is a good absorber of EM energy is a good radiator. Energy radiated longer wavelength than absorbed. • Dark rough surfaces best absorbers
Energy Transfer in Atmosphere • Convection- Heat energy transferred by movements of liquids and gases Caused by density diff in fluids. • Conduction- Transfer of heat energy by collision of atoms, most effective in solids • Radiation- Transfer EM energy through space (Transverse Waves) No medium needed, travels straight at speed of light.
Heat and Temperature • Temperature- Measure of the average Kinetic Energy of molecules within a substance. • Heat- Total Kinetic Energy of the particles in a sample of matter Two jars same temp one jar 50ml of water other jar 25ml of water. If temp is same Avg KE is same Heat energy is diff because larger volume of Water more molecules in motion greater Total KE-More heat energy • Heat always flows from high to low temp. Hot object loses KE cold object gains KE
Video Clip of Temp and Heat Heat Energy
Heat and Temperature c. Calories- The quantity of heat needed to raise the temp of 1 gram of liquid water by 1C. • A joule is defined as the amount of energy expended by a force of one newton moving an object one meter in the same direction as the force. • 1 Joule= .24 cal d. Specific Heat- Quantity of heat required to raise the temp of 1 gram of a substance by 1C. • All substances have a different specific heat value. (Refer to Earth Science Reference Tables) • Takes water 32X longer to heat up than lead higher specific heat more energy required to heat up substance.
Heat Energy and Phase Changes • Latent heat- Normally when we heat things up temp increases • During phase changes the temp of a substance does not change b/c the addition of energy used to convert substance from one phase to another.
Heat Energy and Phase Change Cont.. • Adding heat c. Losing Heat • Melting (S-L) 1. Freezing (L-S) • Evaporation (L-G) 2. Condensation (G-L) • Sublimation (S-G) 3. Sublimation (G-S) • Heat gained or loss can be found by multiplying mass of a substance by latent heat value Varies w/ substance and type of change. (Q=cmΔT), c-specific heat, m-mass of object, ΔT-Diff in temp
Ideas of Latent Heat Glass of Water, still at 0 deg. C + Heat Ice cube 0 deg. C 334 Joules per gram ice Glass of Water, 100 deg.C + Heat Glass of Water, still at 0 deg. C 416 Joules per gram water Glass of Water, 100 deg.C + Heat Steam, 100degC 2260 Joules per gram water. Which processes are Sensible Heat? Latent Heat?
Video clip of Latent Heat Latent Heat
Water and Latent Heat Cont.. • Heat of Fusion-Heat added to 1g of ice at -100C KE increases temp of ice rises to 0C(Melting pt), temp stops rising until all ice changed to liquid. T stays same even though heat is added.(80cal) • Heat of Vaporization-When ice melts to liquid at 0C, temp rises to 100C (boiling pt) temp stops rising b/c all water must turn into gas.(540 cal) • Read left to right-Heating energy gained • Read right to left-Heat loss, energy released to environment fuel for storms.