Fig. 13. Cloud fraction (top) and base (bottom) as a function of time of day, as measured by the ship's ceilometer (solid) and the island ceilometer (dashed), for 24 march-2 April 1996. The evenly-dashed curve is for island ceilometer data processed to 3.66-km altitude (12,000 ft) while the asymmetrically-dashed curve is for the same ceilometer processed to 7.62 km (25,000 ft). The ship's ceilometer acquired data only to 3.66 km. Local noon is approximately 0210 UTC (GMT).