CEE 1030 1nd Edition Lecture 22: AtmosphereOutline of Last Lecture I. SalinityII. Movement of ocean waterIII. Ocean zonesIV. Seawater densityV. Tidal currentsVI. ReviewOutline of Current Lecture I. Origin of Earth’s atmosphereII. Atmosphere layersIII. Atmospheric pressureIV. Weather frontsV. Clouds and precipitationVI. Global wind patternsCurrent LectureI. Origin of Earth’s atmospherea. Gases trapped in planet’s interior released by volcanic eruptionsb. Ancient atmosphere consisted mainly of water vapor and carbon dioxidec. Atmosphere: the layer of gases surrounding the planet, retained by gravityd. Now the atmosphere consists of 78% nitrogen and 21% oxygenII. Atmosphere layersa. 90% of gases concentrated in troposphereb. Denser gases sink, so composition varies with altitudec. Troposphere, stratosphere, mesosphere, thermosphere, exosphered. No distinct upper limit—the atmosphere gradually thins and fades into spacee. Ozone layeri. Layer in stratosphere with high concentration of ozone moleculesii. Absorbs ultraviolet lightIII. Atmospheric pressurea. Barometric pressure: force per unit are exerted by atmosphere on the surface beneath or within itb. Pressure decreases as altitude increasesc. Air in the tropospherei. Warm air is less dense than cold airThese 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.ii. Moving air parcels displace others, resulting in atmospheric convectiond. Coastal breezesi. On coasts, prevailing wind direction changes from day to night because oftemperature differences in air over water and landii. Sea breeze: during the day, air moves from sea onto landiii. Land breeze: during the night, air moves from land out to seae. Atmospheric convectioni. Moving air mass creates a low pressure zone where it began and high pressure zone where it is goingii. Cloud formation1. Convectional lifting: air mass at Earth’s surface is warmed and rises, then expands and cools at higher altitudes, forming clouds2. Adiobatic cooling: when air rises, pressure decreases and air parcel is allowed to expand, resulting in coolinga. If rising air is moist, then water vapor condenses to water droplets as air parcel coolsIV. Weather frontsa. Front: transition zone between air masses of different densitiesb. Fronts extend both horizontally and vertically and are often marked by cloud formationV. Clouds and precipitationa. Cloud: a visible mass of condensed water droplets or ice crystals suspended in the atmosphereb. Clouds form when moist air reaches saturation pointc. Types of cloudsi. Clouds are differentiated by their altitude and whether they are layered or convectived. Cloud formationi. Frontal lifting: convergence of air masses (fronts)ii. Warmer, moister air mass will override cooler, dryer air massesiii. Radiative cooling: when the sun sets and no longer warms the air and ground, air just above the ground cools, forming foge. Precipitationi. Precipitation: condensation of atmospheric water vapor that falls to Earth’s surfaceii. Liquid precipitation1. Rain or drizzle (differentiated by droplet size) forms when separate drops of water fall to Earth’s surfaceiii. Frozen precipitation1. Forms when atmospheric water is cooled below its freezing point2. When it comes into contact with dust particles, supercooled watercondenses around the nucleusiv. Freezing precipitation1. As it falls, crystal moves through warm air layer and melts completely, but then encounters colder air and is supercooledv. Thunderstorms form when air mass with significant condensation is forced upward rapidly in unstable atmosphere, where the temperature drops1. Lightning: atmospheric discharge of electricity resulting from differently charged particles in air massesvi. Tornado: a small cyclone with very strong winds, typically has tube-like condensation funnel extending from rotating cloud base to the ground1. The more different the density of the air masses, the more turbulent the weather front2. Sudden changes n wind direction or speed causes air mass to spin3. Updrafts created by the thunderstorm tilt spinning air mass upward4. Fujita scale: wind speed, etc. based on tornado damagevii. Cyclone: low pressure system with inward-spiraling winds, created by converging frontsVI. Global wind patternsa. Convection circulates air by the unequal warming at different latitudesi. At poles, dense cool air descends and moves toward the equatorii. At equator, less dense warm air risesb. Variation in moisture levels resulting from evaporation and condensation patterns cause cool, dry air to sink at 30 degrees N and 30 degrees S of equatorc. Coriolis effect deflects air currents to the right in the northern hemisphere and tothe left in the southern hemisphered. Jet streams: fast, narrow air currents found near the stratosphere/troposphere transition caused by atmospheric heating and planet’s rotation on the axise. Seasonal changes in solar heating of Earth’s surface affects distribution of high and low pressure areasf. Monsoon: heavy rainy season that lasts for several months with lasting climatic effectsg. Water retains heat better than airi. Temperature varies more in continental interiors than on coastsii. Large bodies of water moderate temperature