Data from different types of dunes suggest that the near surface air-flow over dune lee side varied with dune morphology and primary wind direction relative to dune crest-line. It is found that three types of secondary air-flow exist according to their directions and magnitudes, they are: return flow, attached and not deflected flow, and attached and deflected flow. Return flow, characterized by lower velocity, occurred on stepper lee slops in transverse flow conditions; attached flow with higher wind velocity occurred on gentle lee slops. The attached flow could be deflected in the oblique primary wind environment but not deflected in transverse flow conditions, and its magnitude is the cosine function of primary wind direction relative to dunes . According to the nature of three types of secondary flow, the authors expound the corresponding sedimentary processes and possible stratification types, and also discuss the aeolian cross-strata as an indicator of paleowind environment.
HA Si, WANG Gui-yong
. Variation in Dune Lee-Side Airflow and Its Significance[J]. SCIENTIA GEOGRAPHICA SINICA, 2000
, (6)
: 573
-576
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DOI: 10.13249/j.cnki.sgs.2000.06.573
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