GEOG 040 1st Edition Exam 1 Study Guide Lectures 1 12 Lecture 2 Earth Sun Geometry Seasons Jan 19 Significance of earth s rotation Earth s geometry and tilt on axis Significance of axis we produce day and night light dark Creates a bulge at equator Reasons for Seasons Earth s tilt 1 year full orbit Sometime earth rotating axis 1 time a day Earth tilted at 23 5 degrees why we have seasons Difference between direct and indirect sunlight Feels colder in indirect sunlight larger area Hot in direct sunlight Amount of energy in sunbeam always the same When tilted toward sun Northern direct 6 months Indirect Southern indirect 6 months direct Tilt of earth determines seasons Equinox days and nights are of equal length and sunrays aluminate earth from North Pole to South Pole Lecture 3 Earth s Energy Balance Jan 27 Earth s energy inputs Solar Geothermal Tidal Amount of radiation received at earth s surface depends on amount of Atmospheric moisture in troposphere Particulates in troposphere Reflection of earth s surface Albedo a property surface that relates to its ability to reflect or absorb solar radiation Higher albedo higher reflectance located at Polar Regions Lower albedo lower reflectance located in regions especially the ocean Green House Effect redirection of radiation long wave back toward sun allows earth not to freeze or over heat Energy Expedites Sensible heat flux S energy used to warm air Ground heat flux G energy absorbed into the ground surface Metabolic heat flux M photosynthesis process where plants harvest radiation to produce food Latent heat flux L energy absorbed to evaporate water low evaporation water vapor going back into atmosphere Lecture 4 Atmospheric Pressure and Wind Feb 3 Atmospheric pressure what sets air into motion variation and pressure fundamental to transferring weather and energy What creates pressure system Created by unequal heating from the sun rising air low pressure falling air high pressure Low pressure storm High pressure fair weather Factors that influence wind movements 1 Pressure gradient force air moves perpendicular to isobars and moves high to low 2 Corioli s effect caused by rotation of earth on its axis because earth is rotating from West to East path deflected to right in Northern hemisphere to South hemisphere This dictates air is deflected to right in Northern hemisphere to Southern hemisphere 3 Force of Friction operates to create a drag on air as it moves across the surface so it will created another form of deflection on that air movement only operates on air near surface of the land This drags air as it moves across the earth s surface reduced with altitude Corioli s effect force of friction cyclones Jet Streams form our boundaries between air masses of different temperature They are fast ribbons of air located 25 000 to 35 000 feet above the surface They deviate warm air to south and cool air to north They are very important when tracking weather and cyclones Local Winds Day sea breeze vs night land breeze Day valley breeze vs night Mt breeze Lecture 5 El Ni o What is El Ni o Climate phenomena social phenomena Scrambled weather patterns around the world Sir Gilbert Walker helped world realize weather around the world affects everyone not just specific region Ocean Circulation and effects on climate General circulation in the atmosphere Dominate band of wind from East to West along with Westerly winds moves ocean currents El Ni o example of reoccurring connections and persistent on large scale patterns of pressure and circulation Lecture 6 Atmospheric Moisture and Humidity The global water cycle fluxes of water through earth s system precipitation runoff evaporation and transpiration Flux precipitation comes from atmosphere down to surface of earth Flux runoff flux of water across and through the earth Evaporation flux of water back into the atmosphere in vapor form Transpiration flux of water through vegetation into atmosphere Energy dynamics in phase changes of water Maximum humidity MH max amount of water vapor that on air mass can hold at a different temperature Specific humidity SH measureable amount of actual water vapor in the air example sling psychrometor Relative humidity RH the ratio between the specific and maximum humidity of a body of air Rh SH MH x100 Dew Point the temperature at which a condensation occurs in a definable body of air Atmospheric Lifting Mechanism1 2 3 4 Convection local heating from sun comes from air to rise causing convection current Convergence high low pressure gradients Orographic Lifting topographic barriers movement of air up and over a topography Frontal lifting cold warm air masses Clouds classified to their form and height Cirro form cumulo form strato form nimbo form