Figure 6.12 The influence of clouds on infrared observations. Left: The standard deviation of the radiance from small, partly cloudy areas each containing 64 pixels. The feet of the arch-like distribution of points are the sea-surface and cloud-top temperatures. (After Coakley and Bretherton (1982). Right: The maximum difference between local values of T11- T3.7 and the local mean values of the same quantity. Values inside the dashed box indicate cloud-free pixels. T11 and T3.7 are the apparent temperatures at 11.0 and 3.7 mm (data from K. Kelly). From Stewart (1985).