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Bad Lands Wilderness Area |
Site Name
IMPROVE: BADL1 (Badlands)
Region
Northern Great Plains
Terrain
Badlands National Park consists of
244,000 acres of sharply eroded buttes, pinnacles, and spires in
southwestern South Dakota. The Badlands National Park Area IMPROVE site
BADL1 is located on gently sloping flat in the extreme eastern portion of
the National Park, 4 km northeast of the town of Interior. Site elevation is
736 m (2415 ft) and the lowest elevation in the area is White River (~707 m)
4 km south of the monitoring site. The general topography is plains;
therefore this site is well exposed to regional scale transport winds.
Surrounding terrain is predominantly mixed grass prairie and bare rock/sand.
Terrain in the area is depicted in detailed
20 km terrain
map and 2
km terrain map.
Representativeness
Aerosol data collected at the IMPROVE site should be very representative of
visibility conditions in the National Park and surrounding area.
Nearby Data Stations
This map shows the location of the
nearest air quality and meteorological monitoring sites, with respect to the
Badlands National Park Area. Meteorology is not presently monitored at the
site. There are many COOP and few RAWS sites within the 50 km radius but
most of them are recently established. The nearest
CASTNET site, with meteorological
monitoring, is at Theodore Roosevelt NP, 365 km north-northwest of Badlands
National. Because of the relatively low relief of the northern Plains,
historical meteorological data from that site may provide good
representation of regional meteorological patterns.
The nearest routine upper air site, where atmospheric soundings are
conducted twice daily, is the Rapid City RAOB site, located 110 km
west-northwest of the BADL1. Vertical atmospheric data from Rapid City
should be the best available representation of vertical atmospheric
structure at Badlands National Park Area.
Wind Patterns
The BADL1 monitoring site is exposed to prevailing synoptic wind patterns
due to the flat but gently sloping topography of the region. Winter is
characterized by frequent outbreaks of cold continental air from the
Canadian interior. A severe type of snowstorm that frequently occurs during
this synoptic condition is referred to as the
Alberta
Clipper. During the rest of the year the migration of the jet stream to
more northerly latitudes results in more frequent transport of warmer moist
air from the Gulf of Mexico and warm dry air from the southwestern U.S.
Long-term (1961-2002) Rapid
City wind roses indicate regional surface wind direction frequencies,
although they may be modified somewhat by local terrain. Wind directions in
the area are a consequence of the synoptic pattern and show a high frequency
of flow from the north-northwest year round, with an additional high
frequency component of southeasterly flow during the warm months.
Locally diurnal variations in wind directions depend on terrain and water
features that establish diurnally varying gradients of temperature and
pressure.
Inversions/Trapping
Because of the well-exposed flat to gently rolling sloping terrain near the
BADL1 site, wintertime surface based trapping inversions are probably not
common or severe. The more common inversion condition is probably elevated
subsidence inversions over the region, associated with buildup and
stagnation of synoptic high pressure, especially during the warm months.
They can persist for periods of days until ventilation occurs in conjunction
with frontal passages or onset of stormy low pressure systems.
Climatological Statistics
The EPA CASTNET website
has good climatology data for the Theodore Roosevelt National Park based on
5 years (1998 – 2002). Climatological statistics based on that data should
be regionally representative. For climate of the South Dakota region, the
South Dakota
State University climate website is also a good source.
Meteorological Indicators
Keywords
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