Satellite-Viewed Jet Stream Clouds in Relation to the Observed Wind Field

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  • 1 Stanford Research Institute, Menlo Park, Calif.
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Abstract

Twenty cases of jet stream cirrus clouds observed in TIROS photographs over the United States are related to the atmospheric wind field. The orientation of features such as shadow lines, sharp-edged cirrus sheets, cirrus bands and transverse waves is compared with the horizontal wind and the vertical wind shear in the upper troposphere. Wind data are derived from standard rawinsonde ascents. Differences between the orientation of the major cloud features and the wind direction are generally less than 40°, and tend to decrease with increasing wind speed. Cases that include areas of transverse waves are associated with higher wind speeds and larger vertical shear and static stability than cases without transverse waves. The empirical results of the study are believed to be potentially useful in operational upper air wind analyses in data-sparse areas.

Abstract

Twenty cases of jet stream cirrus clouds observed in TIROS photographs over the United States are related to the atmospheric wind field. The orientation of features such as shadow lines, sharp-edged cirrus sheets, cirrus bands and transverse waves is compared with the horizontal wind and the vertical wind shear in the upper troposphere. Wind data are derived from standard rawinsonde ascents. Differences between the orientation of the major cloud features and the wind direction are generally less than 40°, and tend to decrease with increasing wind speed. Cases that include areas of transverse waves are associated with higher wind speeds and larger vertical shear and static stability than cases without transverse waves. The empirical results of the study are believed to be potentially useful in operational upper air wind analyses in data-sparse areas.

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