Mission investigates tropical cirrus clouds

On moistening of the tropical troposphere by cirrus clouds

Sublimation of ice crystals in cirrus clouds is often invoked as a moistening mechanism for the free troposphere, particularly in the tropics. An alternative mechanism is investigated here: "pumping" of water vapor into the cloudy atmospheric olumn from surrounding regions by diabatic transports resulting from the local radiative effects of the cloud. The effectiveness of this mechanism is comp...

Can cirrus clouds produce glories?

A vague glory display was photographed over central Utah from an airplane beginning its descent through a cirrus cloud layer with an estimated cloud top temperature of -45 and -55 degrees C. Photographic analysis reveals a single reddish-brown ring of 2.5-3.0 degrees radius around the antisolar point, although a second ring appeared visually to have been present over the brief observation perio...

Tropical cirrus and water vapor

Introduction Conclusions References Tables Figures Back Close Print Version Interactive Discussion Abstract Introduction Conclusions References Tables Figures Back Close Print Version Interactive Discussion Abstract We revisit a model of feedback processes proposed by Lindzen et al. (2001), in which an assumed 22% reduction in the area of tropical high clouds per degree of sea surface temperatu...

Cirrus Canopies in Tropical Storms

An analysis is made of the generation, advection, and dissipation processes of the cirrus canopy in tropical storms with particular emphasis on the formation of sharp edges. Although subsidence and accompanying evaporation may be factors, this formation is closely tied with the wind flow pattern near the edges. The stronger the radial wind velocity in the vicinity of the edges, the greater is t...

A sub-tropical cirrus clouds climatology from Reunion Island (21°S, 55°E) lidar data set