Aeolian Processes in the Dry Valleys

This dataset contains data collected during studies of boundary layer winds and
surface characteristics. These field experiments were designed to:
1. Understand and quantify the partitioning of wind shear stress between
surface and roughness elements on (a) rocky surfaces and (b) surfaces with
scatted rocks and intervening sand surface.
2. Test the Raupach et al (1993) shear stress partitioning model to
estimate the entrainment threshold on surfaces covered with isolated roughness
elements
3. Quantify the spatial distribution of surface shear stress on surfaces
with scatted rocks and an intervening sand surface.
4. Understand relations between shear stress partitioning and transport of
sand.

The dataset includes measurements of:
- Boundary Layer winds and surface shear stress
- Wind speed at 6 heights above the surface (6.00 m, 3.65 m, 2.22 m, 1.35 m,
0.82 m, 0.50 m wind direction at 6 m and 0.82 m, temperature at 3.65 m.
- Surface shear stress using Irwin sensors (Wyatt and Nickling, 1997)
- Sand mass transport rates at the Victoria Valley site with static (Nickling
and McKenna Neuman, 1997) and automated sand traps.
Saltation intensity with Sensit sensor at the Victoria Valley site (Gillette
and Stockton, 1986)
- Wind force on simulated roughness elements using the Guelph force balance
(Gillies et al., 2000; Grant and Nickling, 1998; Wyatt and Nickling, 1997).

Data were sampled every 1 second and averaged for 1, 5, and 10 minute
intervals.

Derived data include estimates of wind shear velocity (u*), aerodynamic
roughness (zo)

Surface characterization data:
Information on rock cover and roughness element geometry, and sand grain size
and sorting parameters for surface sand and sand in transport in the Victoria
Valley is also available.

Datasets available:
Data were obtained for 2 sites located on the north side of Lake Fryxell and in
the Victoria Valley. There is also Irwin sensor calibration data for 2 sites:
Wright Valley and Victoria Lower Glacier, which includes wind profile and
temperature measurements.
Data cover the following periods:
- Wright Valley: January 11-14, 2002
- Lake Fryxell: January 15 - February 1, 2002; January 15 - February 3, 2003
- Victoria Lower Glacier: January 11-13, 2003
- Victoria Valley: January 15 - 31, 2003.

Site locations are:
- Lake Fryxell: 77 degrees 36.252 minutes; 163 degrees 07.827 minutes
- Wright Valley: 77 degrees 31.363 minutes; 162 degrees 00.472 minutes
- Victoria Valley: 77.366009935 degrees S, 162.320035048 degrees E

These studies were funded by NSF grant OPP-0088136

References cited

Gillette, D.A. and Stockton, P.H., 1986. Mass momentum and kinetic energy
fluxes of saltating particles. In: W.G. Nickling (Editor), Aeolian
Geomorphology. Allen and Unwin, Boston, London, Sydney, pp. 35-56.

Gillies, J.A., Lancaster, N., Nickling, W.G. and Crawley, D., 2000. Field
determination of drag forces and shear stress partitioning effects for a desert
shrub (Sarcobatus vermiculatus, Greasewood). Journal of Geophysical Research,
Atmospheres, 105(D20): 24871-24880.

Grant, P.F. and Nickling, W.G., 1998. Direct field measurement of wind drag on
vegetation for application to windbreak design and monitoring. Land Degradation
and Development, 9: 57-66.

Nickling, W.G. and McKenna Neuman, C., 1997. Wind tunnel evaluation of a
wedge-shaped aeolian sediment trap. Geomorphology, 18(3-4): 333-346. Wyatt,
V.E. and Nickling, W.G., 1997. Drag and shear stress partioning in sparse
desert creosote communities. Canadian Jornal of Earth Sciences, 34: 1486-1498.