Unit I The Earth System System is an entity composed of diverse but interrelated parts that function as a complex whole Components the individual parts that function as a complex whole part of a system volume mass energy heat energy attribute temp pressure or a sub system Feedback a process internal to a system that acts to either amplify or diminish change imposed externally self perpetuating mechanism of change and a response to that change Positive Feedback amplifies a change in state produces a dramatic change Example Snow melting Negative Feedback diminishes or resists a change in state promotes stability Example An increase in body temperature causing the body to sweat Equilibrium State if the system is in equilibrium it is not changing it will not change unless the system is disturbed Stable negative feedback refer back Unstable positive feedback refer back Perturbation temporary disturbance to a system less than a 100 years Example Volcano El Nino La Nina Seasonal Hurricanes Forcing longer lived disturbance or change more than a 100 years Example The sun Response Time the temperature response to an increase in solar luminosity is a progression from one stable equilibrium state to the next These equilibrium responses are the sum of the response that would occur without feedback plus the feedback effect itself Threshold a condition of a system in equilibrium or undergoing slow change that when exceeded results in a dramatic non linear behavior Small force applied resulting in a massive failure Example Snow avalanche Trees blown down after a while a pencil snapping in half Unit II Global Energy Balance and the Greenhouse Effect Electromagnetic Radiation self propagating electric and magnetic waves or radiation transmitted through the vacuum of space without a medium Wavelength distance between two successive peaks or troughs Radiation moves at the speed of light Frequency the number of wave crests that pass each second Wavelength Frequency Speed of Light 299 792 458 m s Shorter wavelength electromagnetic radiation has higher energy temp Example The Sun hotter body Longer wavelength electromagnetic radiation has less energy temp Example Earth cooler body Flux the amount of energy that passes through a given area during a specific time period the flux of energy decreases by the square of the distance from the source measure it perpendicular Example flux of solar radiation is the amount of energy per unit area Example 2 water passing thru a gate in the Grand Canyon Why are the poles colder than the tropics Poles are farther from the sun The flux radiation is smaller Blackbody object that emits absorbs electromagnetic radiation with 100 efficiency at all wavelengths Example Earth Sun People absorb sun Albedo the reflectivity of a surface If no sunlight reflects albedo 0 Example Roads absorb the sun hot Example 2 Ocean 05 Example 3 Black Roof 0 If all sunlight reflected albedo 1 Example Sidewalk reflects sun keeps cool Example 2 Snow 85 Example 3 Bare Ground 4 The flux of solar radiation to Earth depends on Earths distance from the Sun Earths temperature depends on four factors 1 Sun s Temperature T 4 multiplier effect 2 Distance from the sun D 2 3 Albedo 4 Greenhouse Gases Temperature a measure of the degree of relative hotness or coldness of a body or environment a measurement of its molecular activity the faster molecules are moving the hotter the medium When there is no molecular motion it can get no colder absolute zero Heat Transfer Mechanisms Radiation process in which energetic particles or energetic waves travel through a medium or space Conduction the transfer of heat energy by direct contact between molecules plays little role in atmosphere or oceanic heat transfer Convection process in which heat energy is transported by the motions of a fluid heat transfer by mass motion of a fluid such as air or water when heated fluid is caused to move away from the source of heat carrying energy troposphere is convective because roughly the incoming sunlight is absorbed by the ground and ocean surface Latent Heat is the heat energy gained or released in the transition from one phase to another gas liquid solid releasing energy into the surrounding area Example clouds release energy solid liquid gas consumes energy Example Ice to water to vapor takes energy to heat up and change phase Sensible Heat is measured directly by temperature the speed at which molecules are moving Greenhouse Gas GHG gases that are transparent to shortwave solar radiation but absorb certain wavelengths of Earths longwave radiation any of the atmospheric gases that contribute to the greenhouse effect by absorbing infrared radiation produced by solar warming of the Earth s surface They are selective absorbers Greenhouse Effect the ability of the atmosphere to capture and recycle energy emitted by the Earth surface Residence Time life span of a molecule Water vapor H20v has a short life span of weeks Carbon Dioxide CO2 long residence time of 100years Methane 15years Dominate Greenhouse Gases in the Atmosphere Nitrogen N2 Oxygen O2 Argon AR Water Vapor H2O Carbon Dioxide CO2 4 Dominant Greenhouse Gases Ranked in order of importance 1 Water Vapor 2 Carbon Dioxide CO2 3 Methane CH4 4 Nitrous Oxide NO2 Some greenhouse gases are more effective because there are windows where there is little or no absorbance Greenhouse gases that absorb in these windows are more effective molecule for molecule than additional H20 or CO2 molecules In addition some light and wavelengths absorb differently in the ER electromagnetic radiation Unit III Circulation of the Gaseous Earth Atmospheric Pressure total mass of stuff with more heat there are fewer molecules per unit area less dense Atmospheric Temperature is a measure of temperature at different levels of the Earth s atmosphere It is governed by many factors including incoming solar radiation humidity and altitude Relative Humidity fraction of water vapor in a parcel of air compared to its maximum capacity Warm air holds more water vapor than cold air Absolute Humidity the actual mass of water vapor in a given mass of air Troposphere weather happens clouds rain snow and storm activity mixed convection Tropopause unstable always moving mixed because heated from the bottom Stratosphere helium can go to the stratosphere not well mixed stable The Stratosphere is stratified Stable because it warms upward Troposphere is unstable because it is hottest at the base Condensation is the