Figure 10.

Derived time‐averaged incoming light parameters as a function of wavelength as described in section 4.2. The average is over the period sols 820–1000 for Spirit or equivalently sols 800–980 on Opportunity. This period is marked by the vertical red dashed lines in Figure 9. The vertical error bars are the standard deviations about the mean over this period. The horizontal error bars are the width of the Pancam filters. (left column) Spirit and (right column) Opportunity. (top row) Our derived total incoming radiation relative to what this value would be in the absence of the atmosphere. This is T ₀ as defined in equation (7). (bottom row) The fraction of light in the direct beam, f_D. The red data points are from the L7 (432 nm) data set processed using the values for w_M derived for the R1 (436 nm) filter.