Mean motion field in East Africa at the level of the East African low level jet core

  • E. K. Anyamba
  • P. M. R. Kiangi
Article
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Summary

The mean flow over East Africa at the 1.5 km level during May through September is presented. All available daily wind vectors from 1952–1973 for 22 pilot balloon stations were used.

The southeast-southwest monsoon current is a dominant feature. It is highly diffluent between 38 °E and 40 °E. There is little penetration inland as the current is blocked by the meridionally-oriented highlands. Vertical directional changes show general veering with height. The flow has maximum intensity in July–August with mean peak speeds of 15–17 m/s at 0600 GMT. The layer of strong winds lies between 0.3–2.5 km. Vertical wind shears increase from May, reach a maximum in June–July and decrease thereafter.

Keywords

Strong Wind Directional Change Wind Shear Vertical Wind Wind Vector 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Mittleres Bewegungsfeld über Ostafrika im Niveau des ostafrikanischen “Low Level Jet”-Kerns

Zusammenfassung

Es wird die mittlere Strömung über Ostafrika in 1,5 km Höhe von Mai bis September präsentiert. Dazu werden alle verfügbaren täglichen Windvektoren von 1952 bis 1973 von 22 Pilotballonstationen herangezogen.

Die südöstliche bis südwestliche Monsunströmung ist ein dominierendes Kennzeichen. Sie divergiert stark zwischen 38 °E und 40 °E. Das weitere Eindringen landeinwärts wird durch die meridional orientierten Hochländer blockiert. Die vertikalen Richtungsänderungen zeigen eine allgemeine Drehung mit der Höhe. Die Strömung ist am kräftigsten im Juli und August mit mittleren Windspitzen von 15–17 m/s um 0600 GMT. Die Schicht starker Winde liegt zwischen 0,3 und 2,5 km Höhe. Die vertikale Scherung steigert sich beginnend im Mai, erreicht ein Maximum im Juni/Juli und verringert sich später wieder.

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Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • E. K. Anyamba
    • 1
  • P. M. R. Kiangi
    • 1
  1. 1.Department of MeteorologyUniversity of NairobiNairobiKenya

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