Overview - The Elk Mountain research facility is unique because of its
frequent exposure to clouds. Cloud exposure and high wind speeds result in
strong vertical gradients of cloud droplets and ice crystals at the
mountain/atmosphere interface. The site is therefore ideal for examining
interactions between cloudy atmospheres and the alpine environment.
Because of climatological similarities to regions located at higher latitude,
but lower elevation, data collected at the Elk Mountain can also be used to
better understand polar atmospheric processes and polar atmospheric/biospheric
interactions.
Recent Research - University of Wyoming research conducted at the Elk Mountain
during the 1990's has consisted of the following themes: 1) atmospheric sulfur
dioxide oxidation to sulfate (Snider and Vali, 1994), 2) trace gas
volatilization from ice (Snider and Murphy, 1995; Snider and Huang, 1998), 3)
atmospheric cycling of low molecular weight alcohols Huffman, 1999), and
4) atmospheric nitrogen deposition to alpine tundra soils (Lokupitiya et al.,
2000).
Site Description - The Elk Mountain facility is located at the northern end of
the Medicine Bow Mountain range in southeastern Wyoming. The facility consists
of an observatory, located at the head of Halleck Creek in a small semi-circular
basin (10,850 ft msl), and the Schaefer Hut located atop the western peak of Elk
Mountain (11,000 ft msl). A short grass prairie dotted with cattle and
sheep ranches surrounds Elk Mountain. Aspens grow in the transition
between the prairie and the upper slopes of the mountain, Lodge Pole pine
forests extend from 8,000 to 9,000 ft, sub alpine fir and spruce up to 10,500
ft, and tundra dotted with patches of krummholz occur above 10,500 ft. Elk
Mountain and the surrounding mountain summits are immersed in orographic clouds
with a frequency of 30% during the winter months and 3% during summer.
Access - The facility is located on property owned by the Department
of Atmospheric Science and the University of Wyoming. The Department
operates three Tucker Snow Cats which are used for wintertime travel from the
base of the mountain to the facility. The mountain access road crosses several
privately owned land sections and the University pays an annual access fee to
The Elk Mountain Ranch Company (Peter E. Thieriot, General Manager).
During summer, approximately 3 hours is required to travel from Laramie to the
facility.
Facilities - The facility is supplied with line power from Carbon County
Power and Light. All of the appliances, including the heating system, are
electric powered. There is a small wind tunnel, a cold room, modern
kitchen and bathroom facilities, and room for six adults.
Data Communication and Acquisition - Data communication to and from the
facility is via cellular phone and modem. The data acquisition
system consists of a robust Pentium-based personal computer, National
Instruments acquisition hardware and software, and a signal conditioning system
designed and built in-house. Data can be both archived and analyzed
at the observatory.
Sensors - Meteorological and cloud physics sensors include ambient
temperature, dew point temperature, wind direction and speed (at both the
Schaefer hut and the observatory), and cloud liquid water content. There
is also a nephelometer and several atmospheric chemistry monitors (SO2, O3,
reactive nitrogen, and hydroperoxides) at the observatory. The chemistry
instrumentation has been customized for making low-level measurements.
References -
Huffman, W.A., An investigation of the uptake of low-molecular weight oxygenated hydrocarbons during vapor depositional ice growth, Ph.D. Dissertation, University of Wyoming, 1999.
Huffman, W.A. and J.R.Snider, Oxy-Hydrocarbon / Ice interactions in the troposphere, in press Journal of Geophysical Research, 2003, (http://www-das.uwyo.edu/ccp/world/huffman_snider_2003.pdf ).
Lokupitiya, E., N.L. Stanton, R.S. Seville, and J.R.Snider, Effects of increased nitrogen deposition on soil nematodes in alpine tundra soil, accepted to Pedobiologia, 2000.
Snider, J.R.
, D.C.Montague, and G.Vali, Hydrogen peroxide retention in rime ice, J. Geophys. Res., 97, 7569-7578, 1992.Snider, J.R., and G. Vali, Sulfur dioxide oxidation in winter orographic clouds, J. Geophys. Res., 99, 18713-18733, 1994.
Snider, J.R., and T. Murphy, Airborne hydrogen peroxide measurements in supercooled clouds, J. Geophys. Res., 100, 23039-23050, 1995. (http://www-das.uwyo.edu/ccp/world/snider_murphy_1995.pdf)
Snider, J.R., and J. Huang, Factors influencing the retention of hydrogen peroxide and molecular oxygen in rime ice, J. Geophys. Res., 103, 1405-1415, 1998. (http://www-das.uwyo.edu/ccp/world/snider_huang_1998.pdf )
Information - Jeff Snider, Department of Atmospheric Science, University of
Wyoming, jsnider@uwyo.edu, 307-766-2637, http://www-das.uwyo.edu