7. Atmospheric and Surface Temperature

Photo 12: A thermometer. 2011-06-29

History of temperature measuring

Temperature measurements started already in the latter part of the 1800s with British scientist James Glaisher who traveled up into the troposphere with his balloon, and almost killed himself that way. Temperature is really the measurement of kinetic energy, the speed at which molecules move. Temperature is measured with a thermometer.

Celsius

Celsius is the most common scale for temperature. Swedish astronomer Anders Celsius (1701–1744) used the expansion rate of mercury and set the freezing point of water at 0°C and the boiling point at 100°C.

Fahrenheit

The Fahrenheit scale is used in the United States. Dutch-German-Polish physicist Daniel Gabriel Fahrenheit (1686–1736) used the expansion rate of alcohol, setting the freezing point of water at 32°F and the temperature of a horse at 100°F or 37.8°C.

Kelvin

The Kelvin scale is the modern scientific scale, also following the expansion rate of mercury like the Celsius scale. The Kelvin scale labels the freezing point as 273°K and 0°K is conceptually the absolute zero point at which molecules stop to move. (Remember, temperature is kinetic energy, the movement of molecules.) Photo 12 displays a normal mercury thermometer with Celsius and Fahrenheit scales.

Photo 13: Downtown Calgary, the day before the Calgary Parade. 2010-07-09

Urban Dust Dome

A modern issue in regards to temperature is the phenomenon called Urban Dust Dome and Urban Heat Island. The heat island is caused due to a combination of high levels of fuel combustion and absorbed heat in concrete buildings and asphalt roads. The dust dome is created by warm air circulation that creates a dome from which city dust does not escape. Warm air and small particles rise in the centre of a city as the air is heated, above the city this hot air enters lower pressure area and disperses, the dust particles slowly drift towards the edges of the city, the air at the edges of the city is sucked back into the city because of the low pressure area due to the rising air, thus creating a cycle called urban dust dome. Photo 13 displays a perfect example of the heat island/dust dome effect: human activity combined with a concrete environment.