Methane (chemical formula Ch4), an important greenhouse gas, has a nearly constant mixing ratio throughout the lower atmosphere (0 - 15 km) of 2.1 ppm.
a. Using your knowledge of how the total pressure varies as a function of altitude, sketch and describe the vertical profile of the CH4 number density (i.e. a plot of altitude from 0-15 km on the y-axis and number density on the x-axis, describe the basic function). For this purpose, assume a constant atmospheric temperature of 250 K