Frequency and Magnitude of Aeolian Processes in the McMurdo Dry Valleys, AntarcticaEntry ID: NSF_OPP_0636218
Abstract: This research project provides new information to fill in data gaps regarding the magnitude, frequency, and seasonality of aeolian sediment transport events in three of the McMurdo Dry Valleys: the Taylor, the Victoria, and the Wright. The characterization of the aeolian transport system in these valleys is based on two years of continuous ten minute average observations of wind speed and ... direction, temperature and
saltation activity at four locations within these three valleys. In addition to this high-resolution temporal data, for each of the two years of observation, up to two time/event integrated horizontal saltation flux measurements were made with custom-designed traps that remained open for periods of time regulated by the saltation flux at each of the four measurement locations. These trap-derived fluxes combined with the saltation and wind data has allowed for the characterization of time the saltation system was active, the average flux rates per unit of saltation time, as well as an estimation of the total annual horizontal flux based on the record of the total time saltation was observed to be active. The temporal record of saltation activity is also linked to wind direction and temperature providing information on the daily and seasonal patterns of aeolian transport.
Purpose: The acquired data can be used to further probe the characteristics of the aeolian sediment transport system in the McMurdo Dry Valleys.
Data Set Citation
Dataset Originator/Creator: John Gillies
Dataset Title: Aeolian Process Geomorphology Data, McMurdo Dry Valleys, Antarctica
Start Date: 2008-12-31Stop Date: 2010-01-31
Temporal Resolution: minutes
Temporal Resolution Range: 1 minute - < 1 hour
ISO Topic Category
Quality Overall the recovery for the meteorological, saltation activity data, and sediment collection using the traps was very high with five notable exceptions. In late December 2008 the eastern Victoria Valley site datalogger was submerged under water when the meltwater stream of the Victoria glacier changed its course and flooded the site. The wind speed profile measurements from the first season are ... suspect and were not subsequently used to calculate aerodynamic roughness length and wind shear velocity data. The wind speed and direction measurements at 4.2 m appear to be reasonable. The temperature and saltation activity data also appear to be reasonable and were used in further analysis. The second data recovery problem occurred for wind direction measurements in the Taylor Valley in 2008-2009. At some indeterminate time (or multiple times) the tower rotated due to an anchor line connected to the lowest anemometer boom arm slipping its mooring, thus the wind direction data for that period cannot be used. The third problem was Trap 1 at the Victoria II site fell over at some time and it was not possible to calculate an associated time-integrated horizontal flux. The fourth problem that occurred was that there was very little sediment collected in the trap at the western Victoria Valley site during 2009, although there was ample evidence that transport had occurred. We suspect that it was prevented from rotating for some unknown reason (possibly snow accumulation) for some unknown period of time. The trap was freely moving when we arrived at the site in December 2009, and the saltation activity data indicate activity at levels approaching those observed in the eastern part of the Valley, where large masses of sand were collected. The final problem lies with the Safire saltation sensors for estimating a mass flux of sand. The sensors did register the impacts of saltating grains that provided a means to establish when the saltation system was active. There were also periods when the sensors reached their maximum voltage output in response to the saltation, exceeding their capacity to measure the vigorous saltation that was occurring in response to high wind events. Unfortunately, these data do not allow for the conversion of the mV signal to a flux value using the wind tunnel calibrations with any great confidence.
Data Set Progress
Distribution Format: Excel Spreadsheet
Email: jackg at dri.edu
Desert Research Institute 2215 Raggio Parkway
Province or State: Nevada
Postal Code: 89512
Gillies, J.A., W.G. Nickling, M. Tilson, and E. Furtak-Cole (2012). Wind-formed Gravel Bed Forms, Wright Valley, Antarctica. Journal of Geophysical Research – Earth Surface (submitted).
Gillies, J.A., W.G. Nickling, and M. Tilson (2012). Frequency, magnitude and seasonality of aeolian sediment transport in the Taylor, Wright, and Victoria Valleys, Antarctica. Journal of Geophysical Research – Earth Surface (submitted).
Creation and Review Dates
DIF Creation Date: 2012-06-05
Last DIF Revision Date: 2012-06-06