# Constructing a Model of ppbv of Surface Ozone - PowerPoint PPT Presentation

Constructing a Model of ppbv of Surface Ozone

1 / 8
Constructing a Model of ppbv of Surface Ozone

## Constructing a Model of ppbv of Surface Ozone

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
##### Presentation Transcript

1. Constructing a Model of ppbv of Surface Ozone GLOBE Ozone Protocol Learning Activity

2. Earth’s Atmosphere

3. "The Rest" of Earth's Atmosphere

4. Look at the NumbersComposition of Earth’s Dry Atmosphere(1976 Standard Atmosphere*)

5. Expressing concentration of a gas parts per billion volume number density

6. Let’s look at volume of ozone in this classroom Example: Ozone (trace gas) is probably ~ 20 ppbv in this room. This means that ~ 20 billionths of the volume of gas in this room is ozone. Suppose this room is 6 m wide by 9 m long by 3 m high V = 6 m x 9 m x 3 m V = 162 m3 = 162,000,000 cm3 = 162 x 106 cm3 So what is the volume of ozone in this room? (20 billionths)(162 million cm3) = (20 x 10-9)(162 x 106 cm3) = 3.240 cm3 ~ 3 cm3 ozone in this room

7. How many molecules of gas in 1 cm3? From ideal gas law, in 1 cm3 of air at 25°C and 1 atm, there are 2.5 x 1019molecules “25 billion billion” molecules in 1 cm3

8. Let’s look at number density for ozone Example: Ozone (trace gas) is probably ~ 20 ppbv in this room What is number density of ozone(2.5 x 1019 molecules/cm3)(20 x 10-9) =50 x 1010 molecules ozone/cm3 =500 x 109 molecules ozone/cm3 or 500 billion molecules ozone/cm3