Vertical wind shear measurements in the lower stratosphere

✍ Scribed by D. Cadet

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 464 KB
• Volume: 101
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49710142907

✦ Synopsis

Abstract

During two flight series of superpressure constant‐level balloons conducted in the lower stratosphere by the Laboratoire de Météorologie Dynamique, the vertical wind shear vector over 100 metres has been measured. It has been found from a record of almost two months that the r.m.s. wind shear is about 1·5 × 10^−2^s^−1^. The shear can reach 5 × 10^−2^s^−1^ in association with a breakdown of the stably stratified flow. From the records of wind shear vectors over 100 metres, 15 wind shear hodographs have been drawn which in turn have been divided in two groups. In the first group, the shear vector keeps a constant direction with time and in the second one it rotates anticlockwise with a 7 to 8·5 hour period suggesting the existence of gravity‐inertia waves in the flow. The modulus of the wind shear oscillates with a similar period but this feature is found whichever the group to which the hodograph belongs.