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Grand
Teton National Park |
(Also see Teton Wilderness,
Yellowstone National Park, and
Red Rock Lakes
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.
Grand Teton National Park occupies
309,995 acres along the Teton Range and adjacent Jackson Lake. The Teton
Range borders the west side of the National Park, with elevations exceeding
3,658 m (12,000 ft) at peak summits. The highest elevation, at the summit of
the Grand Teton, is 4,198 m (13,770 ft). The eastern half of the Park
consists of Jackson Lake and valley of the upper Snake River. The Lowest
Park elevation is 1,936 m (6,800 ft) where the Snake River exits the Park at
the south boundary. The Park is adjacent to the Teton Wilderness to the
northeast and is 10 km (6 mi) south of Yellowstone National Park and the
headwaters of the Snake River. Terrain is mountains and craggy peaks on the
west side that shadow Jackson Lake and the Snake River on the east side.
The IMPROVE site representing Grand Teton National Park, as well as the
Teton Wilderness, Yellowstone National Park, and Red Rock Lakes National
Wildlife Wilderness, is YELL2, located in central Yellowstone National Park
near the north shore of Yellowstone Lake. YELL2 is 60 km (37 mi) north of
Grand Teton National Park, across the Continental headwaters divide between
the Yellowstone River and Snake River watersheds. 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 aerosol measurements should be representative of composition and
characteristics in the Grand Teton National Park. It may at times be
decoupled from air at higher elevations when contained within a surface
inversion over Yellowstone Lake.
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 CASTNETsite 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 Summariesare 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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Last updated 16 December 2004
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