Energy Transfer Slides PDF

Energy Transfer  Air Pressure: Kinetic Molecular Theory Density of Molecules decreases with height. Although the atmosphere goes up to 300 km, half of the atmosphere is in the first 18,000 feet or 5.5 km Less molecules (same composition) higher up makes it is harder to breath than at s...

Energy Transfer  Air Pressure: Kinetic Molecular Theory Density of Molecules decreases with height. Although the atmosphere goes up to 300 km, half of the atmosphere is in the first 18,000 feet or 5.5 km Less molecules (same composition) higher up makes it is harder to breath than at sea level. Air Pressure is converted to Sea Level Pressure to observe surface low and high pressures. (otherwise the Rocky Mts. would be always be low pressure and the oceans would be areas of high pressure). Pressure also dependent upon Temperature WHY DOES TEMPERATURE FALL AS YOU GO UP IN THE ATMOSPHERE? THE MOLECULES IN THE MESOSPHERE ARE SPREAD VERY FAR APART (LOW DENSITY) – DESPITE ITS LOW DENSITY, IT IS STILL MORE DENSE THAN THE NEXT LAYER ABOVE IT (THE THERMOSPHERE) WHICH IS WHY METEOROIDS BURN UP FROM THE FRICTION HERE AS A RESULT, THE MOLECULES DO NOT COLLIDE OFTEN FEWER COLLISIONS OF MOLECULES RELEASES LESS HEAT, SO TEMPERATURES ARE LOWER  Go with the Flow 1. Air flows from high to low pressure. This is called Bernoulli’s principle Transfer of Heat Energy 1. Radiation 2. Conduction 3. Convection  Radiation The transfer of heat energy by electromagnetic radiation. Earth is heated by this process. - various substances on earth (dirt, rocks, water, concrete, sand, etc.) absorb this energy and their heat level is raised. They transmit that heat through mainly convective heat transfer to the surrounding atmosphere, and eventually to us.  Conduction The transfer of heat energy from one substance to another or within a substance. Very effective in heating metals Air is a poor conductor.  Convection The transfer of heat energy in a fluid. Commonly seen in the kitchen when you see boiling water Air in the atmosphere acts a fluid  CONVECTION CURRENTS UNDERGROUND MAGMA LOSES HEAT ENERGY TO THE CRUST AS IT PUSHES THE SURFACE PLATES AS MAGMA AS THE EXPANDS MAGMA FROM THE COOLS, IT ADDITIONAL CONTRACTS HEAT, IT AND BECOMES BECOMES MORE DENSE LESS DENSE SO IT SINKS AND RISES BACK TO THE TOWARD THE SURFACE CORE MAGMA IS HEATED BY THE EARTH’S CORE  CONVECTION CURRENTS IN THE AIR THE WARM AIR COOLS AS IT RISES (TEMPERATURES IN THE TROPOSPHERE FALL AS ALTITUDE INCREASES) AS THE AIR IS AS THE AIR WARMED BY COOLS, IT HEAT RADIATING CONTRACTS BACK FROM THE AND FALLS BACK EARTH, IT TOWARD EXPANDS AND EARTH’S RISES SURFACE THE COOLER AIR RUSHES TO FILL THE VOID LEFT BY THE RISING WARM AIR (CREATING WIND)  Transfer of Heat Energy Summary 1. Radiation 2. Conduction 3. Convection Earth-Atmosphere Energy Balance  The Effects of Clouds Nighttime: clouds keep the earth warmer Daytime: clouds keep the earth cooler Hydrologic Cycle  Summer Monsoon Air over land heats and rises drawing moist air in from tropical oceans Ocean Circulation? Ocean surfaces are heated by incoming surface radiation 90% of solar radiation that penetrates oceans absorbed in upper 100 m Warm water at surface is less dense than the colder water below Water has a high heat capacity – Lots of heat required for a small change in temperature Ocean Circulation Ultimately driven by solar energy – Distribution of solar energy drives global winds – Wind belts produce ocean currents Determine circulation patterns in upper ocean – Surface temperature gradients drive circulation – Net effect is to move warm water to poles and cold water towards tropics Heat Transfer in Oceans Heating occurs in upper ocean Heat transfer from equator to pole by ocean currents Oceans redistribute about half as much heat at the atmosphere Coriolis effect influences ocean currents – Water deflected to right in N. hemisphere – Water deflected to left in S. hemisphere  Gulf Stream Western boundary current in Atlantic – Narrow, fast-moving – Flow broadens and slows becoming N. Atlantic Drift Thermohaline Circulation Deep ocean circulation depends on temperature (thermo) & salinity (hals) – Controls seawater density Density increases as: – Salinity increases – Temperature decreases – Flow of water in deep ocean is slow However, still important in shaping Earth’s climate Thermohaline Conveyor Belt NADW sinks, flows south to ACC and branches into Indian and Pacific Basins Upwelling brings cold water to surface where it eventually returns to N. Atlantic Glacier Ice Melting Glaciers and icebergs are fresh water. When they melt into the world’s oceans they are slowing the thermohaline circulation. This is causing/will cause major shifts in climate due to the slowing of the ocean currents. Ice on Earth Important component of climate system Ice properties are different from water, air and land – Two important factors affecting climate High albedo heat stored in ice ALBEDO (Latin for “Whiteness”) Land has higher albedo than ocean Clouds have high albedo Ice and snow have high albedo