Impressions of our fieldwork in California, USA, April 30th - May 7th, 2022
Here we are measuring Aeolian sand flux, wind shear stress, E-fields,.... and admiring the sand ripples, the Aeolian streamers and the sunset @ Palm Springs train station.
Ultrasonic anemometers and Irwin sensor in action to measure the wind shear stress over Dumont dunes. Photo: Eric Parteli.
High-efficiency, low-cost Aeolian sand traps in action @ Palm Springs, California. Photo: Eric Parteli.
Aeolian transport layer. The crest-to-crest distance of the ripples is about 10 cm.
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Aeolian Megaripples - or dwarf dunes - and "normal" Aeolian ripples, side by side near Salton Sea, California. The crest-to-crest distance of the normal (straight-crested) ripples is about 10 cm.
Coarse grains on the crests, fine grains in the troughs: The "inverse grading" of Aeolian megaripples is direct consequence of the different hop lengths of big and small grains, explain Robert Anderson and Kirby Bunas.
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Caught on camera! These are dwarf transverse dunes near the train station of Palm Springs. However, they are breaking apart into small crescent-shaped (barchan) bedforms once they reach the bare asphalt, owing to the transverse instability of dunes that has been explained in this Physical Review Letters.
Now a video of the transverse instability of (dwarf) dunes, or Aeolian megaripples, near the train station of Palm Springs!
Avalanches and Aeolian transport in the dune lee, Palm Springs.