Temperature and Ground Hog day

Temperature and Ground Hog day1Ground Hog DayGround Hog Day - if the ground hog sees his shadow there will be 6 more weeks of winter.

German superstition used animals to predict weather. Germany used a hedgehog.

Pennsylvania - German settlements - 1887 - first ground hog named Phil. Today is the 5th generation in Pennsylvania - 7:00 a.m. Penn. Time in Globber Hill -Ground Hog Club. A very big tradition - people dress up and many tourists come to see the festival. Ground Hogs usually hibernate. They are woken up for the tradition. Phil is about 14 pounds.

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3Proclaimation being read for ground hog day at Globber Nob

4Punxsutawney Phil making his annoucement!

5Feb 2, 2013

6Atmospheric Properties that describe weather conditions7Temperature vs. HeatTemperature vs. Heat - Temperature measures how rapidly or slowly molecules move around.Heat is the transfer of energy because of difference of temperature between substances.Temperature Scales:

8Causes of weatherMeteorology study of atmospheric phenomena Greek meaning of Meteors high in the airTypes of atmospheric meteors Clouds, raindrops, snow flakes, fog, dust, rainbows

9Cloud droplets - hydrometersLithometeors- smoke, haze, dustElectrometeors- thunder, lightning

Weather current state of atmosphere.Climate long term variation determine over 30 years span or more.10TropicsTemperature is constant there. Why? Through constant motion of air and water relocationAir masses large body of air that takes on the characteristics of the area in which it formed (Source Region).Land Air masses less moistureWater Air Masses more moisture ( high evap.)11Classification of Air MassesAccording to source region(CT) Continental Tropical warm and dry(MT) Martime Tropical warm and humid(CP) Continental polar cold and dry(MP) Maritime polar cold and humid( A) Arctic Much colder same as continental polar air masses associated with very high pressure.. 12

13Source Region5 main types of air masses in the U.S. due to the continents location to the source regions associated with each air mass.Maritime polar (California) Forms over the North Atlantic and North Pacific. This is why we have heavy rains in the winter.14Source Regions contContinental Polar- freezes the middle /Northern part of the U.S. Forms over the interior of Canada and Alaska.

Maritime Tropical Air forms in tropical and subtropical oceans ( Caribbean Sea and Gulf of Mexico)15Source Region cont.Maritime Tropical Air- forms in the Western U.S. Summer brings hot humid weather to the eastern 2/3 of the U.S. and Canada.Continental Tropical Air Desert Southwest and Mexico and source region , Hot/DryArctic- Develops over latitudes of 60 N Ice Regions of Siberia and Arctic Basin

16Air Mass ModificationAs air masses move over the surface of the earth, they acquire the characteristics of other source regions, In time loses its identity.

Weather systems- earth rotates around the sun ,The rotations causes the Coriolis Effect. S, Hemisphere: deflect to leftN Hemisphere : deflect to right17Hadley CellThis cell creates a belt of high pressure. It causes weak surface winds. Called Horse Latitude

18ITCZInter Tropical Convergence Zone Air converges and is formed upward. Area of low pressure forms over a large area. Low pressure migrates wit movement of the suns rays.

Weather is normally cloudy with showers. Great for the tropical rain forest.

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20Trade WindsBetween 30 * N and 30* S Air sinks, warms and moves back toward 30* and sinks again ( warm air rises, cold air sinks). Example of a Convection cell. 21Prevailing WesterliesLocated between 30* and 60* They move opposite of Trade winds. The winds blow towards the poles in an easterly direction( blows for west to east) Responsible for the weather for the U.S.

22Polar EasterliesLies 60 * N and 60* S Characterized by cold air.23Jet Streams Narrow band of fast, high altitude westerly winds Speed are up to 185 km/hr 2 Jet Streams Polar Jet separates Easterlies from prevailing westerlies. Subtropical Jet Stream-Where trade winds meet prevailing westerlies.24Jet Streams

25Cold FrontCold dense air replaces warm air forcing it upward. Warm air condenses as cooling Clouds, showers and thunderstorms associatedThe Front moves fast so a steep front developThe points on the symbol indicates the directional movement. 26Cold Front Symbol

27Warm FrontWarm air displaces the cold air Warm front is a gradual slope due to the air in front moving slower.The warm front encounters less frictionWeather is extensive cloudiness and precipitation. Points on the symbol point in the directional movement.

28Warm Front symbol

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30Stationary FrontThe meeting of two air masses and neither is moving in a direction.Occurs due to modifications that have occurred there is little imbalances.Weather patterns are similar to a warm front.31

3233Occluded Front Cloud air mass moves so rapidly it overtakes a warm frontCold air mass wedge pushes the warm air upwards.34

35Occluded Front

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37Summary of Front Symbols

38Pressure SystemsRising air associated with low pressureSinking air associated with high pressureWeather is basically rotating High and low pressure produced by rising and sinking air combined with the Coriolis effect39Rotation of Pressure

40High Pressure Air sinksThe air reaches the surface and spreads outAir is deflected to the right or clockwise in the Northern Hemisphere. It rotates to the counter clockwise in the Southern Hemisphere. Associated with cold air masses, fair weatherFound in subtropical oceans 41High Pressure

42Low PressureAir rises and is replaced by air from outside the system so it flows toward the center.Weather is cloudy and precipitationFound in the middle latitudesWave cyclone begins along a stationary frontImbalances occur and pushes the front south and another part north.Weather produced affects large areas.43

44Saturation - point at which air holds as much H 2O vapor as possible. Condensation cannot happen until saturation is reached.H2O vapor changes to liquid (rain)

45Saturation of Air

46Vertical Temperature ChangesAs air masses rise over, mountains tend to cool. Remember clouds are suspended H2O vapor. As cloud rises, temperature cool then condensation temperature reach LCL (lifted condensation level) base level of clouds. Above LCL air becomes saturated and cools more slowly. The rate that saturated air cools is called the moist adiabatic lapse rate.Range - 4C/1000m to 9C/1000m (warm air) (cold air)

47Meteorologist measure atmospheric variables:temperature; air pressure; wind; relative humidity to make accurate weather forecastsThe two most important factors of weather forecasting are: accuracy and density of data

48InstrumentsThermometers - measures temperature - heights of liquid column indicates temperature from the expansion of the liquid. There are two types: mercury and alcohol.

Barometer - measures air pressure. There are two types: mercury barometer - air pressure changes with the height of the mercury. aneroid barometer - metal container with a vacuum chamber inside. This chamber contracts or expands with changes in air pressure.

49Mercury Barometer

50Aneroid Barometer

51Hydrometer- measures relative humidity

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Ceilometer - measures the height of the cloud layers. It also estimates the amount of cloud cover.

53ASOS - Automated surface observing system - gathering data in 1700 areas at regular intervals

54Accurate forecasting requires atmospheric data at height of 3000mRadioscope - measures upper level data - temperature, pressure, and humidity.Doppler Radar - measures wave frequency that occurs in energy such as sound and Light Data is plotted - indicates wind speed and the movement of the front.Weather satellites - takes a picture of earth at regular intervalsInfrared Imagery - used to measure surface temperature difference. * Detects strong thunderstorms.

55Doppler Radar - measures wave frequency that occurs in energy such as sound and Light Data is plotted - indicates wind speed and the movement of the front.

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Weather satellites - takes a picture of earth at regular intervals

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Infrared Imagery - used to measure surface temperature difference. * Detects strong thunderstorms.

59Weather AnalysisStation Model - Record of weather data for a particular siteAllow meteorologists to fit a large amount of date into a small spaceProvides a uniform way of communicating:

60Plotting data Across a piece of landIsopleths - lines connecting points of equal or constant valuesIsobars - lines of equal pressureIsotherms - line of equal temperature

61Isopleths

6262Isobars

63Isotherms

64Barometric - Pressure 78 78 90 6050 90 90 88 90 88 88 78 50 78 55Isobars are close together - strong windsIsobars are far apart - calm windsReliable forecast must rely on analyzed date from different levels of the atmosphereDigital forecast - Forecasts that are ones that rely on numerical data. Highly Dependent on the density of data - main method usedAnalog forecast - comparing current weather patterns to the past. Used for monthly and seasonal forecasts

65Digital Forecast

66Analog Forecasting

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