Chapter 3: Air Temperature Daily Temperature Variations  Maximum temperature recorded late afternoon  Minimum temperature recorded just before sunrise  Incoming radiation stops around late afternoon  Afternoon temperature recorded around Later during the summer earlier during the winter  All of this, of course, depends on Cloud cover and Local effects such as Santa Ana winds and ‘offshore wind effects’

Daily Temperature Range Daily temperature range  Difference between the daily maximum and daily minimum temperatures Daily range in temperatures is much larger on clear days than on cloudy days Daily Temperature Range Can depend on  Cloud cover  Humidity Annual Temperature Range  Difference between the average temperature of the warmest and coldest months

Warmest part of day late afternoon

Radiation Cooling Occurs at night Creates a ‘radiation inversion’  When ground is cooler than air above  Can observe fog at ground on after a storm

Cold temperatures At night Warm daytime Temps Clouds help To keep in temps

Radiation cooling Causes valleys to Be cold at bottom

Special Topic Record high temperatures Record low temperatures When it comes to temperature, what is normal? A thousand degrees and freezing to death

Controls of Temperature Latitude  Equator  Polar regions Land and water  Beaches  Mountains  Deserts Ocean currents  California current/Gulf stream Elevation  Valleys/mountains/coast

Specific Heat Amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius Takes more heat to raise temperature of oceans than to raise temperature of land. This explains why our ‘oceans’ have memory of heat stored and can determine climate over ‘decades’.

Mean Average Temperature This is the average temperature of any weather station for the entire year Average is just a fancy name for ‘normal’ What is normal temperature for L.A. for this time of year? This can be applied to the rainfall total for this time year

Tables to look at…. Wind Chill Table……3.2 How cold the wind makes us feel The ‘feels like’ temperature

Measuring air temperature Instrument Shelter  Liquid glass thermometer  Maximum Thermometer  Minimum Thermometer

Instrument shelter must be at Least several feet from the ground

Automation of Weather Instruments Automated Surface Observing Systems (ASOS) Electronic weather stations

End of Chapter 3 Key Terms Questions for review 1, 2, 3, 5, 6, 8, 9, 10, 14ab, 15 Questions for thought….. 1, 2, 5, 7, 8