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Scapegoat Wilderness Area |
(Also see Bob Marshall Wilderness and
Mission Mountain Wilderness)
Site Name
IMPROVE: MONT1 (Monture)
Region
Central Rockies
Terrain
Terrain is shown in the 2 km terrain map and the 20 km terrain map. The
239,936 acre Scapegoat Wilderness is located in northwestern Montana
straddling the Continental Divide immediately south of the Bob Marshall
Wilderness. Most of the area lies between the elevations of 1,525 m (5,000
ft) at the Blackfoot River to 2,900 m (9,400 ft) on Red Mountain. Topography
of the Scapegoat includes rugged ridges, gently sloping alpine meadows,
forested slopes and river bottoms.
The IMPROVE site representing Scapegoat, Bob Marshall, and Mission Mountain
Wilderness Areas is MONT1, located near the USFS Monture Creek Guard
Station. It is about 15 km (10 mi) southwest of the Scapegoat Wilderness
Area boundary at a valley bottom location on the north side of the Blackfoot
River valley near Monture Creek. The site elevation is 1,293 m (4,241 ft).
Representativeness
The MONT1 IMPROVE should be representative of Scapegoat Wilderness and
regional conditions when the atmosphere is well mixed. It is at a valley
bottom location and may be unrepresentative when trapped within a winter
type surface based valley inversion that isolates it from the Wilderness
Area, 15 km distant and across the local headwaters divide. During upvalley
flow conditions, it may give a good indication of potential transport from
the Missoula area towards Wilderness locations via the Blackfoot River.
Nearby Population/Industrial Centers and Local Sources
This western Montana Wilderness Area is remote from any major source
regions. With respect to the MONT1 monitoring site, the nearest major
population center is Missoula, 70 km southwest of MONT1 and downstream from
MONT1 via the Blackfoot River. Nearby emission sources may be associated
with the timber and mining industries.
Nearby Meteorological Network Monitoring Stations
Nearby meteorological monitoring network stations are shown in the data
network map and at the
US Climate Archive
and RAWS station US Climate
Archive sites. There are no nearby monitoring network stations
representative of concurrent meteorological conditions at MONT1. The nearest
meteorological monitoring site with long term data representative of
regional conditions is probably the Missoula NWS station, 70 km southwest.
Historical data for this and other first order NWS stations are available
via the EPA Technology
Transfer Network website.
The closest upper air site is Great Falls Montana (TFX), 140 km (~ 90 mi)
east. Data for this and other upper air sites are accessible via the
University of Wyoming Dept
of Atmospheric Science web page.
Wind and Transport Patterns
Regionally, wind patterns and transport flows are dominated by westerly
synoptic flows, with frequent easterly flows in the winter. Monthly
Missoula Montana wind roses
indicate this pattern, with northwesterly flow predominant at this surface
station and a significant east-southeasterly component in the winter. Note
that these surface wind patterns may differ somewhat from upper level winds
because of terrain effects. The MONT1 site is on the north side of the
Blackfoot River Valley near the mouth of two drainages exiting the mountains
from the north. It is subject to diurnal flow patterns on two scales, with
microscale drainage from the north via Monture and Dunham Creeks, and
mesoscale upvalley flow from the direction of Missoula via the Blackfoot
River valley.
Inversions/Trapping
The MONT1 site is subject to surface inversion trapping within the Blackfoot
River valley, especially during the winter when such radiation inversions
may persist for periods of days before being broken up by surface heating.
During these periods the site may be unlinked to regional flow, with buildup
of locally generated pollutants, including emissions from sources downvalley
in the direction of Missoula. In the summer regional subsidence inversions
during periods of high pressure and stagnation can result in regional
aerosol buildup over periods of days. High regional aerosol concentrations
may occur during summertime stagnation and subsidence inversion periods in
conjunction with western wildland fires.
Climatological Statistics
Missoula Montana
Normals Means and Extremes should be representative of the MONT1 site
and similar elevations in this part of western Montana. Other
Montana Climate
Summaries are available from the
Western Regional Climate Center.
Meteorological Indicators for Local Sources
Keywords
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