TITLE:
Dust as a Potential Tracer for the Flow over Topography
AUTHORS:
Pinhas Alpert, Joseph Barkan
KEYWORDS:
Dust, Sahara, Froude Number, TOMS, Topographic Flow
JOURNAL NAME:
International Journal of Geosciences,
Vol.6 No.1,
January
26,
2015
ABSTRACT: The distribution of
mineral dust around topographical obstacles is examined, employing the
dimensionless Froude number that describes different flow regimes in a fluid.
Flow around a peak with a near-circular shape in a dusty environment like the
Sahara and the Sahel was examined in order to investigate the distribution of
the dust around the obstacle. The Total Ozone Mapping Spectrometer Aerosol
Index (TOMS-AI) daily Aerosol Index, the u and v wind components and the
temperature, were used for the period 1979-1992,i.e. 14 years. It is found by
the AI data that the shape of the dust distribution around the circular peak is
in good agreement with the shape of the peak itself. Additionally good
correlation exists between the vertical distribution of the dust above the peak
and the Froude Number in its vicinity. This method allows for the first time
the investigation of the flow above and around topographical obstacles in
different flow conditions in the open space employing dust as the flow tracer.