wind machine, a strong fan for stirring up and mixing cold, dense air settled on the land surface with warmer air from above, thereby preventing frosts on still spring nights when there is no wind to do the job. Such machines, introducing an aeronautical look to vineyards, have been used on valley floors that are prone to radiation frosts, such as in the napa Valley of California. helicopters can be used to the same effect.
© Jancis Robinson and Oxford University Press 1994, 1999, 2006, 2015
