Atms 120 Wcp2

Weekly Challenge Problem #2: Moisture Due: Sept 16, 2012

After another Illini football victory, you decide to invite your ATMS 120 TA, Nathan, over to your tailgate party. It is a warm day and Nathan asks you for a drink and you pour him a tall glass of tea and throw in a few ice cubes to cool the drink down. Nathan really likes sweetened tea, so you give him some sugar and as he pours the sugar packet into his glass, you realize that you forgot a spoon to stir the tea with. Suddenly, Emily (your other ATMS 120 TA) swoops in with a solution. You see, Emily was out taking temperature measurements around campus and therefore they had a thermometer that would serve perfectly as a stir stick for Nathan’s tea. As he is stirring, you realize that you also forgot a koozie, so everyone at the party watches closely for condensation to form on the side of the glass. As soon as the glass begins to sweat, Nathan pulls out the thermometer and takes a reading – he finds the temperature of the tea to be 10°C when condensation formed on the outside of the glass. He then takes an air temperature reading a few feet from the glass and finds the air temperature to be 30°C. See if you can answer the following questions about this situation. (Hint: you will make a lot of use of figure 1.9 on page 11 of the text. You may also want to watch this video for a little help.)

http://www.atmos.uiuc.edu/~snodgrss/moisture/moisture_vodcast.html

1. Write down the equation for relative humidity in the space below.

Relative Humidity = (Vapor Pressure/Saturation Vapor Pressure) * 100%

2. What is the saturation vapor pressure (SVP) of the air at the tailgate?

The saturation vapor pressure of the air is 42.4mb.

3. What is the dewpoint temperature (Td) of the air at the tailgate?

The dewpoint temperature is 10°C.

4. What is the vapor pressure (VP) of the air at the tailgate?

The vapor pressure of the air at the tailgate is 12.3mb.

5. What is...