Meteorology

Meteorology: The study of the entire atmosphere including its weather The atmosphere: Air is a mixture of many gases in Earth's lower atmosphere Nitrogen and oxygen together form about 99% of dry air by volume The reaming 1% is mainly argon and carbon dioxide Structure of the atmosphere Troposphere- is the lowest layer of the atmosphere (0-12 km) in which all of earth's weather occurs Gradually decreases in temp. with an increase in altitude Contains all water vapor The jet stream is located between 16-12 km Tropopause- the top of the troposphere where the decrease in temp. stops Stratosphere- reaches from the tropopause to about 50 km above the earth Steady winds and few weather changes (planes fly here) Steady increase in temp. with the increase of altitude Which is caused by absorption from the ozone <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Ozone- ultraviolet rays make oxygen 03. the ozone layer absorbs sun's UV rays and protect us from burning <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Stratospause- the top of the stratosphere where the temp. stops rising <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Mesosphere- temperature drops again <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Thermosphere- temperature rises again about 500 km from earth <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Weather- is the state of the atmosphere at a given time and place <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">To try to predict weather you need to observe the clouds, wind, temp., humidity, air pressure and precipitation over a period of time <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Heating of the atmosphere <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">energy from the sun results in changes in the weather. Hear moved through the atmosphere in three ways <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Conduction- an object receives hear when it comes into contact with a hotter object. (Ex: a pan on a hot stove) <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Radiation- hot bodies radiate energy in short waves (sun); cold bodies radiate energy in longer waves (earth) <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Convection- most effective; the rising of hot air and sinking of cold air results in a steady flow. Convection is very important in moving heat through the atmosphere <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Insolation: <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Solar energy that reaches the Earth; we receive one two-billionth of the sun rays <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Greenhouse effect: <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Short ultra violet waves from the sun are able to reach the earth's surface then longer infrared waves re-radiated by the earth's surface are trapped by greenhouse gases.(CFC's and CO2) <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Normal lapse rate- the rate of cooling with altitude (1 degree Celsius for every 160 meters) <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Smog trapped by temperature inversion <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Warm air over cool traps smog in valley <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Specific heat <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">The amount of heat required to raise the temp. of something 1 degree Celsius <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Water has a high specific heat compared to soil. <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Absorption- to take in energy and heat up <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Reflection- to bounce back energy <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Re-Radiation- to absorb short wave energy and give off long wave energy <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Good absorbers Poor absorbers <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Dark colored Light colored <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Rough surface Smooth surface <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Dry soil Wet soil <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Heating of land and water: <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Which heats up faster? <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Water warms much more slowly then land <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">In water the sun's rays go to a depth of many meters. On land the sun rays heats only the top few centimeters of soil <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Water can spread heat easily because it is a fluid <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Some solar energy is used int eh process of evaporation. Thus, less solar energy is available to raise the temperature of the water. <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Water cools more slowly than land because its heat is spread through a greater depth <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Temperature: <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Temperature: is a measure of the energy of molecules. The more energy that molecules in the air have the hotter it feels. <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Temperature is measured in degrees (Celsius,Fahrenheit,Kelvin) <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Thermometers are the instruments used to measure temperature <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">The alcohol expands when heated <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Thermogrpahs are self recording thermometers <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Isotherms- are lines drawn on maps connecting places with the same temperature <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Evaporation <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">The change from liquid water to water vapor <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Water vapor is spread throughout the troposphere by convection currents and winds <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">Humidity: <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">the capacity of air for holding water vapor <span style="color: #50ef92; font-family: Verdana,Geneva,sans-serif;">As air temperature increases so does the amount of water vapor it can hold <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Specific humidity- the amount of water vapor actually presents in the air <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Relative humidity- Compares the actual amount of water vapor int the air (spec. humidity) with the maximum amount of water vapor the air can hold at that temperature <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Psychrometer- is the instrument used to determine relative humidity <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Condensation: <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">The change from water vapor to a liquid. This occurs when the temperature drops low enough that the capacity for water vapor in the air drops below the specific humidity. <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Examples- Water vapor which condenses on surfaces, such as grass, in the form of a liquid <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Dew Point- temperature at which saturation occurs. <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Air may be cooled below its dew point it many ways: <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Contacting a colder surface <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Radiation heat <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Mixing with colder air <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Expanding when it rises <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Water vapor needs to condense on something! <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">Condensation Nuclei- tiny particles, such as salt, sulfate, or nitrate particles on which water vapor condenses <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">When cooling occurs by contact with a colder surface the water vapor condenses directly on that surface <span style="color: #806363; font-family: Verdana,Geneva,sans-serif;">>0 ℃= dew <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;"><0℃= Frost <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Fogs: <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Surface layers of air a few hundred meters thick which are called below the dew point. As water vapor condenses tiny droplets stay suspended in the air by the lightest air movement <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Radiation fogs- At night the ground loses heat rapidly. Light winds mix the cold bottom air with the air a short distance from the surface. When the whole layer of air is cooled below the dew point, a forms. (common in humid valleys and near rivers and lakes) <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Advection Fogs- results when warm moist air blows over cool surfaces (ex. coastal California) <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Clouds: <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Clouds form when air above the surface cools below the dew point <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Precipitation: <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">is the falling of any from of water from the air to the Earth's surface <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Occurs when cloud droplets grow into drops heavy enough to fall to Earth <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Rain drops: form from tiny droplets and then grow by bumping into and combining with other droplets <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Sleet: forms when raindrops fall through the freezing air and fall to the ground as pellets of ice <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Hailstones: begin as a frozen raindrop and grows by collecting smaller ice particles or liquid cloud droplets <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">Acid Rain- forms when water condenses on sulfate and nitrate. <span style="color: #f17777; font-family: Verdana,Geneva,sans-serif;">As temperature and dew point get closer together <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">1) Relative humidity goes up(when they are equal it is 100%) <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> 2) Condensation is likely and the cloud cover will be greater <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> 3) Precipitation is more likely <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Air pressure: <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> The weight of the atmosphere per unit area <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Difference in air pressure causes the Earth's wind and weather changes <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Pressure decreases with altitude <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Barometer: <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> is an instrument used to measure air pressure <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Aneroid Barometer: <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> measure pressure with a thin metal can <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Millibar- is a metric unit of pressure <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;"> Standard sea-level pressure is 1013.2 MB** <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">Isobar- lines that join points having the same air pressure at a given time <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">Each line is worth 4 mb <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">High pressure area (high)- the area of the largest pressure. The pressure in a high is greater than the surrounding area <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">Low pressure are (low)- This area has lower pressure than the surrounding area. <span style="color: #ffff00; font-family: Verdana,Geneva,sans-serif;">Pressure gradient- the rate of change for air pressure between two points. <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Rising barometer- greater pressure usually means cooler dries weather (sinking air) <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Falling Barometer- Less pressure because the air is warm and moist and rises. This can be a sign of precipitation. <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Wind: <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">the horizontal movement of air from areas of low air pressure <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">The closer the spacing between isobars the stronger the winds <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Winds blow across isobars from high to low air pressure <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Global wind belts: <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Wind flows from high pressure at the poles to low pressure at the equator <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">The wind is deflected by the Earth's rotation, called the Coriolis effect <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Anemometer is the instrument used to measure wind speed <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Wind vane- is used to measure wind direction <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Air Masses: <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">An air mass is a huge section of the lower troposphere that has the same kind of weather (temperature and moisture properties) throughout <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">The best source regions for air masses are large flat areas where air can be stagnant long enough to take on the characteristics of the surface below <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">Air masses have to characteristics <span style="color: #fe4da3; font-family: Verdana,Geneva,sans-serif;">temperature depends on whether it comes from the tropics or polar regions <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">The humidity of the air mass depends on whether it comes from land or sea <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Air masses are named from their source region <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">c-continental <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">m-maritime <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">T-tropical <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">P-polar <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">A-Arctic <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Boundaries between air-masses are called fronts: <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Cold front: <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">1) cold air is advancing and replacing warm air <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">2) cold fronts are steeper and move faster than warm fronts <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">3) the air rises upward rapidly forming cumulonimbus <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">4) heavy precipitation and thunderstorms which stands and end quickly are associated with cold fronts <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Precipitation covers 75-100 miles and occurs both before and after a cold from passes a the surface <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">6) Cold fronts travel at speeds between 25-30 MPH <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">7) as soon as the front passes the temperature will decrease and the wind speed may rise <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">Warm front: <span style="color: #4dbefe; font-family: Verdana,Geneva,sans-serif;">1) warm air is advancing and replacing cold air <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">2) warm front move slower; warm air moves up a gentle frontal surface <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">3) warm air may travel 1000 KM before rising 2 or 3 KM <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">4) First citrus and cirrostratus clouds form and then there are alto stratus clouds. finally steady rain falls from nimbostratus clouds <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">5) Precipitation can occur from 225-275 miles ahead of where the front touches the found <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">6) warm fronts travel at speeds between 20-25 MPH <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">7) warmer temperature follow the passing warm front <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">Occluded front: <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">1) a cold front is advancing and combining with a warm front <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">2) occluded fronts move the slowest of all 20 mph <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">3) These fronts are associated with cirrus and stratus clouds in front of numbostratus and cumulonimbus clouds <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">4)Precipitation occurs for about 400 miles, most of which is in front of the frontal boundary <span style="color: #ca00ff; font-family: Verdana,Geneva,sans-serif;">5.) Cool air is in front as warm air is forced up by the cold air which follows the passing occluded front