The Salton basin is an arid, sub-sea level basin located in southeastern
California. Mountain ranges border the basin directly to the west and
east, to the north extends a narrow valley that terminates with a
transverse mountain range, and to the south spans heavily irrigated,
agricultural lands that gradually rise in surface elevation. Within the
basin lies the Salton Sea, and surrounding the Sea is diverse terrain
that includes dry playa, rocky and vegetated surfaces, and highly
emissive alluvial fans and dry washes, among others. Although large dust
outbreaks due to orographically forced high wind speed events are
frequent in the area, measurements from a new AERONET site stationed
within the basin shows that dust is a standard component of the region's
atmosphere, even on days with otherwise low wind speeds. We find a
diurnal cycle of background dustiness that peaks in the early afternoon.
An analysis of boundary layer structure using a Vaisala CL51 suggests
that deepening of the boundary layer due to dry convection results in
downward mixing of momentum, increased surface wind speeds, and an
accumulation of dust in the mixed layer. Further analysis of the CL51
observations at nighttime suggest that high AOD concentrations persist
in the shallow nocturnal boundary layer, and can become elevated
throughout the night due to westerly katabatic flows. An analysis of
surface meteorological station data suggests possible pathways of
suspended dust due to mountain and valley flows within the basin.