2. Consider a satellite-based instrument aimed at detecting the presence of methane from space.
a. How might this instrument:
i. ‘Exploit’ the Question 1 physical property to detect greenhouse-active gases in general? [1 mark]
ii. Be ‘tuned’ to detect methane? [2 marks]
b. Why would a ‘water-vapour filter’ be a necessary feature of this instrument? [1
mark]
c. Why wouldn’t a ‘molecular Oxygen and Ozone filter’ be needed? [1 mark]