Consider a planetary atmosphere that consists entirely of one gas with absorption coefficient m 2 k abs = 0.01 kg . The pressure at the surface of this planet is equal to lOl3hPa. Its atmosphere m is isothermal with a constant temperature of 16C. The gravitational acceleration is 9.815 2 . For a downward beam of incoming radiation a) Estimate the height and pressure of the level where the optical depth along the normal (ie. along the local vertical) direction is unit (2 1). b) Estimate the height and pressure where the optical depth is unit (= 1) for slant paths of the beam with zenith angles equal to 30 0 and 60 0 , respectively. [Note that, the optical depth ('1') is the (In) of the ratio of incident to transmitted radiant flux through an atmospheric layer]