LECTURE 6 | TEMPERATURE (PART 1)
• It is a measure of the average speed of atoms and molecules.
• Higher temperatures mean faster average speeds.
• Three temperature scales are commonly used:
o Kelvin (no negative values!)
• Liquid-in-glass: mercury or alcohol
• Electrical/electronic: resistance varies with temperature
• 5 feet (~1.5 m) above ground
• over a natural surface (grass)
• well ventilated
Air Temperature Means & Ranges
• Mean Daily Temperature:
o average of the max and min temperature during a 24-hour period
▪ Max=93, Min=69
• Daily Temperature Range
o Maximum minus minimum temperature
▪ Max=93, Min=69
• Global Extremes
o Due to continentality, temperature extremes occur at continental interiors
o World record high was 57°C (136°F) at Azizia, Libya.
o World record low was -89°C (-129°F) Antarctica.
o More extreme temperatures have occurred across the globe at locations
without temperature observation stations. • Mean Monthly Temperature
o average of mean daily temperatures for the month
• Mean Annual Temperature
o average of the 12 mean monthly temperatures
• Annual Temperature Range
o highest minus lowest monthly mean temperature
Annual Temperature Cycle
• The annual temperature cycle is driven by Earth-Sun relationships.
• The months of highest and lowest temperature, however, do not coincide with the
periods of maximum and minimum insolation....
• We call this difference a LAG in seasonal temperature.
• It occurs because of the energy balance.
• In the winter, there is still more radiation leaving than coming in during Jan and
• so temperatures continue to cool even though the days may be longer and the
sunlight more direc