The solar noon radiation values at the top of the atmosphere above Maun are 1366 W/m 2 on February 2 and 1074 W/m 2 on August 2. Why are values for surface solar receipt shown in the two figures lower? You are not to compare the two locations. You are to explain why the surface receipt is lower than the top of the atmosphere. February 1 February 2 February 3 Figure 3-2. Hourly radiation fluxes-Maun, Botswana, February 1-3, 2000..