(b) The cosine of the solar zenith angle is given by cos 8 = sin o sin 6 + cos o cos o cos w (1) where o is the zenith angle, o is the latitude, 6 is the declination angle, and w is the hour angle. Simplify Eq. (1) for the equator and the poles, and use your simplified expressions to show that the seasonal variations in insolation are more dramatic at the poles than at the equator in the following two aspects: (i) the intensity of sunlight at solar noon, [5 marks] (ii) the number of daylight hours. [5 marks]Gravitational acceleration on Earth 9 =9.8ms -2 Gravitational constant G = 6.67 x 10-11 mokg-1s-2 Avogadro number NA = 6.02 x 1023 Mass of Earth MEarth = 5.972 x 1024 kg Molecular mass of air Mair = 29gmol-1 Molecular mass of oxygen (O) Mo = 16gmol-1 Molecular mass of sulfur (S) Ms = 32g mol-1 Surface pressure due to atmosphere above Psurf = 1 bar Density of liquid water Pw = 1 gem-3 Earth's radius REarth = 6371 km Solar irradiance at top of atmosphere S' = 1368 Wm-2 Stefan-Boltzmann constant 0 = 5.67 x 10-8 Js 'm-2K-4