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Red
Rock Lakes Wilderness Area |
(Also see Yellowstone National Park, Grand Teton National Park, and Teton
Wilderness Area)
Site Name
IMPROVE: YELL2 (Yellowstone National Park)
CASTNET: YEL408 (Yellowstone National Park)
Region
Central Rockies
Terrain
Terrain is shown in the 2 km terrain
map
and the 20 km terrain map.
The 32,350-acre Red Rock Lakes National Wildlife Wilderness occupies most of
the Red Rock Lakes National Wildlife Area in the Centennial Valley of
western Montana, bordered by the Centennial Mountains to the south and east
with elevations up to 3,050 m (10,000 ft). The Wildlife Area is a high
altitude (2,000 to 2,750 m, 6,600 to 9,000 ft) waterfowl refuge occupying
valley floor wetlands in the upper Centennial Valley. The Wilderness is 80
km (50 mi) west of Yellowstone National Park.
The IMPROVE site representing the Red Rock Lakes National Wildlife
Wilderness, as well as Yellowstone National Park, Grand Teton National Park
and Teton Wilderness Area, is YELL2, located in central Yellowstone National
Park near Yellowstone Lake. YELL2 is 100 km (60 mi) east of the eastern Red
Rock Lakes Wilderness boundary, with mountainous intervening terrain. The
YELL2 site elevation is 2,425 m (7,954 ft), 67 m (220 ft) above the nearby
Yellowstone Lake elevation of 2,358 m (7,733 ft). The
Yellowstone National Park CASTNET
site YEL408 is nearby, elevation 2,400 m (7,872 ft), 42m (138 ft) above Lake
level.
Representativeness
YELL2 should be representative of Red Rock Lakes National Wildlife
Wilderness when the atmosphere is well mixed and regionally homogeneous,
especially during the warm months. Because it occupies lower elevations of a
headwaters basin in a different watershed than YELL2, aerosol composition in
the Red Rock Lakes Wilderness could be unlinked to YELL2 and less well
represented by YELL2 aerosol measurements, especially during winter surface
inversions.
Nearby Population/Industrial Centers and Local Sources
YELL2, located in central Yellowstone National Park, is remote from any
major source regions. The nearest population centers are the Idaho
Falls/Pocatello Idaho area 200 km (120 mi) southwest of YELL2 in the eastern
Snake River Plain region of Idaho, and Helena Montana 225 km (140 mi)
north-northwest of YELL2. The Naughton and Bridger Power Plants in
southwestern Wyoming are ~ 300 km (200 mi) to the south. Nearby emission
sources may include smoke from natural and anthropogenic burning. Highest
aerosol concentrations at YELL2 resulting from local/regional sources may
occur during regional wildfire events. A wintertime study of snowmobile
emissions indicated that particulate emissions from 2-stroke snowmobile
engines have a potential for visibility impacts in the Yellowstone National
Park airshed (Sive et al, 2003). The YELL2 site is near the Lake Ranger
Station, one of the sampling sites for that study. References to this and
other related studies are available at the
Montana
DEQ Clean Snowmobile Facts web page.
Nearby Meteorological Network Monitoring Stations
Meteorological monitoring network stations close to YELL2 are shown in the
data network map and at the
US Climate Archive
and RAWS station US Climate
Archive sites. The
Yellowstone National Park CASTNET site YEL408 is in close
proximity to YELL2 and should provide the best available representation of
local surface meteorology concurrent with aerosol monitoring. Historical
data for regional first order NWS stations are available via the
EPA Technology Transfer
Network website.
The closest upper air site is at Riverton Wyoming (RIW). 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 from the north-central U.S. and
Canadian interior in the winter. Monthly
Pocatello Idaho wind
roses are indicative of this pattern, with southwesterly flow
predominant at this surface station and a significant northeasterly
component in the winter. Note that these surface wind patterns may differ
from upper level winds because of local terrain effects such as the eastern
Snake River Plain where Pocatello is located. Aerosol transport from distant
source regions to the vicinity the YELL2 monitoring site will most often be
via the upper level predominantly westerly winds.
Locally, YELL2 is near the northern shore of Yellowstone Lake. Local surface
wind patterns are shown in
Yellowstone National Park wind roses based on 1996-2003 data from the
Yellowstone National Park CASTNET
site YEL408. These show predominantly southwesterly flow, especially for
higher wind speeds. Light wind speeds have a significant north-northwest
component associated with drainage flow and a possible land/lake breeze from
higher terrain north of the site during nighttime. Annual daytime strong
winds are almost exclusively from the southwest in line with prevailing
upper level synoptic flow, and light winds from the south to southeast the
probable direction for upslope and possible lake breeze flow.
Inversions/Trapping
The YELL2 IMPROVE site is sufficiently close to the level of Yellowstone
Lake to be beneath frequent prolonged wintertime surface trapping inversions
during periods of cold temperatures and regional high pressure. During these
inversions episodes the site is subject to the buildup of emissions from
local and nearby sources while decoupled from upper level transport flow and
higher elevations. In the summer regional subsidence inversions during
periods of high pressure and stagnation can result in widespread aerosol
buildup over periods of days. High summertime aerosol concentrations at
YELL2 may result from more regional sources such as western wildland fires
in conjunction with such episodes.
Climatological Statistics
Climatological data derived from
Yellowstone NP CASTNET site YEL408 data should be most
representative of YELL2.
Other Wyoming
Climate Summaries, Idaho
Climate Summaries and
Montana Climate
Summaries are available from the
Western Regional Climate Center.
Meteorological Indicators for Local Sources
Keywords
Reference
Sive, B., D. Shively, and B. Pape, 2003. Spatial Variation of Volatile
Organic Compounds Associated with Snowmobile Emissions in Yellowstone
National Park University of New Hampshire Climate Change Research Center.
Submitted to the National Park Service, US DOI. October 25, 2003.
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