2. Spectral irradiance at the top of atmosphere is 1.2W m2 nm¹¹, at the surface level is 0.7W m² nm¹. Assuming there is no absorption at this wavelength and extinction is due to the scattering of molecules and aerosols, calculate transmittance, total optical thickness and optical thickness of aerosol layer if Rayleigh optical thickness is 0.08. What is the scattering cross-section of aerosols if the thickness of aerosol layer is 2.5 km. Sun zenith angle (from vertical) is 40 degrees.

2. Spectral irradiance at the top of atmosphere is 1.2W m2 nm¹¹, at the surface level is 0.7W m² nm¹. Assuming there is no absorption at this wavelength and extinction is due to the scattering of molecules and aerosols, calculate transmittance, total optical thickness and optical thickness of aerosol layer if Rayleigh optical thickness is 0.08. What is the scattering cross-section of aerosols if the thickness of aerosol layer is 2.5 km. Sun zenith angle (from vertical) is 40 degrees.