Raindrop Measurements during Project Shower

Raindrop size distributions have been obtained on the island of Hawaii with filter papers and with a device called a drop recorder. The drop recorder automatically exposes a section of dyed paper tape to the rain at approximately two-minute intervals. The maximum sized drop found on each of the more than 4,000 samples has been plotted as a function of time. It is shown that a fair correlation exists between the maximum sized drop and rain intensity.

Over 300,000 drops m⁻³ < 0.2 mm diameter have been found in very light rains at altitudes of 5,500 feet on the volcanos of Mauna Kea and Mauna Loa.