Cloud Forms of the Jet Stream

Abstract

A combination of four cloud types including specific forms of cirrus, cirrocumulus and altocumulus have been successfully correlated with the reported location of the major axis of the jet stream. Recognition of these cloud patterns from the ground may prove to be a simple method for locating the high velocity component of the jet. Field observations of these spectacular clouds have been made at various parts of the United States. More than 500 feet of time-lapse motion pictures have been obtained of such clouds and show remarkable high velocity, shear, turbulence and waves which typify portions of this high velocity stream of air. These cloud structures display the coherency and the high rate of motion which would be expected of the jet stream. Preliminary studies have indicated that the proximity of the major axis of the jet stream sometimes modifies air motions at low altitude and may be responsible for excessive winds on mountain summits and anomalies of forest fire behavior. Detailed studies by time-lapse photography should establish more of the physical properties of this important component of the atmosphere.