(Also See Lava Beds
Wilderness Area)Site Name
IMPROVE:
LABE1 (Lava Beds Wilderness Area
Region
Great Basin
Terrain
Terrain is shown in the 2 km terrain
map and the 20 km terrain
map.
The South Warner Wilderness consists of 70,385 acres on the Warner Mountain
Range, an isolated spur of the Cascade Range in extreme northeastern
California. Elevations range from about 1,600 m (5,250 ft) along the eastern
Wilderness Boundary to 3,016 m (9,892 ft) at the crest of Eagle Peak Terrain
is gently rolling on the western slopes, with steeper eastern slopes.
The IMPROVE site representing Lava Beds and South Warner Wilderness Areas is
LABE1, located near the southern end of Lava Beds Wilderness at an elevation
of 1,469 m (4,818 ft). LABE1 is 110 km (70 mi) northwest of the South Warner
Wilderness Area.
Representativeness
The LABE1 IMPROVE site should be very representative of aerosol
characteristics at Lava Beds Wilderness Area. It should also be
representative of the South Warner Wilderness Area during regionally
homogeneous atmospheric conditions that prevail during worst haze conditions
in this isolated area of northeastern California.
Nearby Population/Industrial Centers and Local Sources
The nearest population area and potential source region, with respect to the
LABE1 IMPROVE site, is the northern Sacramento Valley to the southwest,
separated from the Lava Beds and South Warner Wilderness Areas by the
northern Sierra Nevada and southern Cascade Ranges. High aerosol
concentrations at LABE1 may result from regional forest fires. Entrained
crustal material from exposed desert surfaces may be a source of particulate
matter during strong wind episodes.
Nearby Meteorological Data Stations
Meteorological monitoring network stations close to the LABE1 site are shown
in the data network map and at the
RAWS station US Climate Archive
site. The Indian
Well California RAWS site is located near the center of the Lava Beds
Wilderness Area and 5 km northwest of LABE1, thus very representative of
meteorological conditions concurrent with aerosol monitoring at LABE1. The
Timber Mountain
California RAWS site is located at a well exposed site 20 km southeast
of LABE1 and is representative of mesoscale to synoptic scale wind patterns
at Lava Beds Wilderness Area. The nearest upper air site is the Medford RAOB
station in southern Oregon, 130 km northwest of LABE1
Wind and Transport Patterns
Lava Beds and South Warner Wilderness Areas are located at the northwestern
fringe of the Great Basin physiographic region. Synoptic winds in the area
are generally northwesterly (from the northwest), with an additional
component of more southerly winds in the winter with the weakening of the
Pacific High Pressure System and establishment of a typical wintertime Great
Basin High. This pattern is indicated in monthly
Medford Oregon Wind Roses.
At times during the extended summer a significant southerly component of
flow from the California Sacramento Valley could bring lofted Sacramento
Valley emissions to the area over relatively low lying terrain between the
southern Cascade Range and northern Sierra Nevada Range. Worst haze
conditions at LABE1 may result from regional forest fires during regional
stagnation episodes.
Inversions/Trapping
The LABE1 IMPROVE site is in a relatively wide basin, and strong local
surface based trapping inversions are probably rare. The area is subject to
larger scale subsidence inversion episodes associated with regional surface
high pressure over the Great Basin that can cause buildup and stagnation of
aerosols over periods of days. These regional subsidence inversions, with
typical heights of 2,000 to 3,000 m (6,000 to 10,000 ft) could hold aerosol
accumulations at the LABE1 site. Highest concentrations may result when this
warming and drying condition leads to major forest fires in Southern Oregon
and northern California.
Climatological Statistics
Long term
Lava Beds National Monument Climate Data are representative of Lava Beds
Wilderness Area and the LABE1 IMPROVE site. Other
Northern California
Climate Summaries are available from the
Western Regional Climate Center.
Keywords