Speedy Raindrops

Abstract: Do all raindrops fall at terminal speed? Recent speed versus size measurements of drops during natural rainfall show that sub-mm raindrops often fall up an order of magnitude faster than expected. Furthermore, images of drop clusters reveal that these ‘‘super-terminal drops’’ are differently sized fragments of a recent break-up, moving with the speed of the parent drop and relaxing towards steady fall. Immediately after breakup, the pieces, disembarking off a common carrier, move at about the same (relatively high) speed. Along with reviewing the physics of drop breakup, I shall discuss possible implications, e.g., disdrometers and Doppler radars. Close abstractClose abstract