GEOS 212 1st Edition Exam 2 Study Guide OCEANOGRAPHY REVIEW SHEET KEY FOR EXAM 2 Review session 6 30 8 00 exam 8 00 9 30 on 31 Mar in Mod Lang 350 Review session 6 308 00 exam 8 00 9 30 on 1April in Soc Sci 100 In class Thurs 2 April in Holsclaw by sign up on D2L Following are the main topics that we have covered since Exam 1 In addition to the terms and concepts listed below please make sure you are familiar with the large scale processes that we have discussed for example realize that surface currents are important for both climate and mixing of seawater Also become familiar with the many diagrams and map features that we have discussed and that you have seen used in homework Atmosphere circulation Atmosphere transports water and energy Patterns of pressure temperature gas content and humidity in atmosphere Condensation energy out Evaporation energy in how h20 transports energy Pressure is measured as the weight of air above you the more air the heavier it weighs the higher the pressure will be Thus atmospheric pressure decreases as you move up Temperature decreases as you move up as a results of pressure changes Gas content is the atmosphere includes 78 nitrogen 21 oxygen carbon dioxide water vapor Humidity in the atmosphere depends on the temperature o it is expressed as water present water max o For example a cold atmosphere can hold a maximum of 1 water a warm atmosphere can hold a maximum of 3 water Thus a cold atmosphere with any higher than 1 water means rain These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Patterns of motion and driving force of motion simple non rotating model to real world Air moving up rainy and low pressure o think of air evacuating giving other air molecules room to move Air moving down clear dry high pressure o Think of air pressing hard down causing high pressure and evaporation out Global air circulation has o rising moist air at the equator o sinking dry air at 30 N S Simple real How atmosphere circulation controls climate temperature and rainfall Hadley cell air rises at equator sinks at 30 N S semicircular air circulation o Rising air is associated with rainfall and low pressure o Sinking air is associated with clear dry climate and high pressure Thus these air patterns explain global patterns of deserts rainforests Main wind belts and non wind belts on planet Non wind belts Storm latitudes 60 N S Horse latitudes 30 N S Doldrums equator Why it rains a lot on the equator but not at 30 N S rising vs sinking air Air rises at the equator since the sun s energy is concentrated there Rising air is associated with low pressure and a rainy climate thus the equator is rainy This same air dries out and sinks when it reaches 30 N S sinking air is associated with a dry climate and high pressure Thus it is dry at 30 N S How heat is transported on large and small scale within atmosphere it s the water Heat is transported in the atmosphere by the condensation energy out and evaporation energy in of water 70 80 of the heat moved by the hydrologic cycle Important diagram Using condensation Weather prediction using atmospheric pressure High Low Pressure High pressure condition when air is sinking cause dry environments because there is little rainfall and low pressure condition cause wet rainy environments So we can use this information to predict weather Key Points Hadley Cells rise at equator sink at 30o N S Rising Air cools can t hold as much water vapor condenses RAIN Sinking Air warms can hold more water as vapor evaporation DRY Good to know why rising sinking air lead to rain dry climate Surface currents what drives the 5 major gyres the direction of wind belts patterns of motion tend to follow the general direction that the wind belt is blowing and tend to end up circling based on local wind patterns A gyre will normal turn once per year The gyres tend to transport heat away from the equator and redistribute the energy FIVE reasons Gyres are important 1 2 3 4 5 Keep ocean very well mixed uniform salinity Carry warm water westward Explains East West differences in climate Carry heat away from the equator Controls life in oceans mobility and migration Why weather different on west east coasts of US relate to ocean gyres circulation Patterns of temperature in the oceans and how related to atmosphere and ocean circulation The oceans are notably warmest at the equator because that s where the sun s energy is concentrated This contributes to the warm rainy climate of the equator and causes the air at the equator to rise Circulation of the gyres in the ocean moves the heated water from the equator WESTWARD and AWAY from the equator thus redistributing the heat and allowing the equator to be cooler Patterns of salinity in the oceans and how related to atmosphere processes and currents Salinity in the ocean is relatively uniform This is because the ocean gyres are constantly mixing the oceans Salinity tends to be at higher values at warmer locations near the equator because a lot of evaporation is occurring in this hot environment Wind generated waves height wavelength velocity fetch duration set velocity fully developed sea Be able to do some simple calculations using wind wave set velocities and be able to explain positions relative to fully developed sea curve Wind speed and wave speed positive correlation Wave height and wind speed positive correlation Wave height depends on the coupling of wind speed and friction across the water how bumpy Wave height depends on wind speed but also on fetch and duration A fully developed sea is one where the winds have blown long enough and over a large enough distance to generate the wave height Set velocity the speed at which sets of waves travel 1 2 wave speed Calculating when waves will arrive somewhere Waves along shore changes near shore how waves move sediments along shore Wave breaks a wave includes water movement up until a maximum depth of 1 2 the wavelength When the bottom of the wave begins to come in contact with the ocean floor This contact slows the bottom of the wave down but the top of the wave keeps going at the same speed As a result the top crashes over the bottom of the waves and we see rolling beach waves If waves were parallel to the shoreline we would observe a marked piece of sand stays in the same place along the shore and just comes in and out with the waves In longshore transport current