What was the composition of the early atmosphere?Early Atmosphere:Consisted of hydrogen (H), helium (He), methane (CH4), and ammonia (NH3)Volcanic eruptions introduced nitrogen, carbon dioxide, and water vapor into the atmosphereMolecular oxygen introduced from photosynthesis of algae (that’s how we got oxygen)The oxygen produced ozone, which trapped UV radiation and allowed for plant growth on land (stops us from frying up)Of the atmosphere today?Molecular Nitrogen (N2) – 78%Molecular Oxygen (O2) – 21%The remaining 1% is mostly ArgonTraces of carbon dioxide, methane, water vapor, etcThese “trace” gases are important because they are highly reactiveWhat are the sources and sinks of atmospheric carbon dioxide?Sources:Volcanic ActivityRespirationThe burning of fossil fuels (pollution)Plant DecayDeforestationSinks:PhotosynthesisOceansCarbonates (carbon in the rock in the earth which creates limestone – limestone caves are big depositories of carbon)How does the hydrological cycle work and what are the different phases of water?Hydrologic Cycle:Fueled by incoming solar energyExchange of water between “reservoirs”Evaporation, Transpiration (plants release water vapor into the air), Condensation, PrecipitationKnow the layers of the atmosphere.Troposphere – where we live –temperature decreased with heightTropopause – where temperature increases with heightStatosphere – temperature increasesStatopause point where it beings to decreaseMesophere – decreaseMesopause - point where it begins to increaseIn which layers does the temperature increase with height?Tropopause, Stratosphere, MesopauseDecrease with height?Troposphere, Stratopause, MesophereWhat are the 5 main processes of energy transfer? How does each work?All weather events require an energy sourceConduction:Transfer of energy through matter (air is a poor conductor)If you hold a metal rod in a fire eventually the heat will rise to the top of the rod and burn your handConvection:Transfer of energy by movement of mass (liquids and air)In liquidsAdvectionEnergy transfer by horizontal movement of airCold front –-> cold air taking over the warm airLatent Heating: the heat absorbed or released per unit mass when water changes phasesLatent heat of melting: energy absorbed by water to change ice to liquid waterLatent heat of fusion: amount of energy released to the environment when water freezesLatent heat of vaporization: amount of heat required to evaporate liquid waterLatent heat of condensation: the amount of energy released when water vapor condenses to liquid formDeposition: Phase change from gas to solidSublimation: Phase change from solid to gasDefine latent heat. Know that latent heat is released during cloud formation (condensation). During what phase changes is latent heat released? And taken in?Sublimation, Evaporation, and Melting are all cooling processes (removes energy from the atmosphere)Condensation, Freezing and Deposition are all warming processes (add energy to atmosphere)How does the intensity of incoming radiation change with latitudeRemember this involves the area over which the radiation is spread.Radiation:energy in the form of waves that are not composed of matterRadiation Law:all objects with a temperature above absolute zero emit radiationWien’s Law:the hotter the object, the shorts the wavelength of maximum emission of radiationWhen radiation interacts with an object it can be:Absorbed, Reflected, or Transmitted (ART)Albedo:Describes the percentage of light an object reflects (snow has a high albedo)The amount of radiation energy the atmosphere absorbs depends on radiative properties of the material, amount of time exposed to energy, the amount of material, the proximity to the energy source, and the angle at which radiation occursKnow that seasons occur due to the tilt of the Earth, which is tilted at 23.5 degrees.Why do the tropics receive an energy surplus and the poles an energy deficit? How is heat distributed from the tropics to the poles?Polar Regions emit more than they absorb (energy deficit)Tropics Absorb more than they emit (energy surplus)Ocean currents and atmosphere distribute heat poleward, keeping the poles from cooling and the tropics from warmingThe further poleward you travel, the more daylight you have during the summer and the fewer daylight hours in the winterAt what time of day is the temperature the greatest? Remember this occurs right before sunset, where the sun has been out for the longest period of time.Diurnal Temperature Cycle:Has air temperature increasing all morning long to an incoming solar peak at noonAfter noon, the energy gains still exceed the losses until around 4pm when maximum daily temperature is reached (sunset)The energy losses then exceed the gains all night long, with a minimum temperature around sunriseKnow the 5 controls of temperature. Why do coastal areas have more moderate temperatures? (Specific heat of land vs. water)LatitudeAngle of inclination affects incoming solar energy and causes the seasonal cycle in temperatureInsolation: the amount of energy at the top of the atmosphereHigher insolation = higher temperatureInsolation levels affected by latitudeSurface TypeBecause the atmosphere is heated by the Earth’s surface, the surface type plays an important role in the surface air temperatureElevation and AspectHigher altitude = colder temperatureB/c the air is less dense and there are fewer molecules to absorb incoming solar radiationAspect is the direction that a mountain slope facesSouth facing slopes receive more solar energy and are warmer than north-facing slopeRelation to Large bodies of waterThermally stabilize the temperature of the surrounding air, so that the difference between months are reducedDue to water’s high specific heat (more heat required to increase the temp. of water and it cools down much slower than land)Temperature of nearby water also modifies a region’s temp.Cloud coverClouds reflect and absorb solar energyThey reduce the amount of solar radiation at the surface causing daytime cooling and have a warming effect, which can very pronounce at night, when they emit longwave radiation toward the surfaceWhat is a dry adiabatic lapse rate, and how is the moist adiabatic lapse rate different? These define the rate of cooling for a rising bubble of air.Lapse rate: change of temperature with heightAir that moves up and down in the atmosphere undergoes temperature changesA rising parcel always expands