(Also See South Warner
Wilderness Area)Site Name
IMPROVE:
LABE1
Region
Great Basin
Terrain
Terrain is shown in the 2 km terrain
map and the 20 km terrain
map.
The Lava Beds Wilderness Area consists of 28,460 acres in the
Lava Beds National Monument in
northeastern California, bordering the eastern slopes of the Sierra Nevada
range, 70 km northeast of Mt. Shasta. Wilderness terrain is flat, gently
sloping upwards towards the southwest. Elevations range from about 1,200 m
(4,000 ft) to 1,740 m (5,700 ft).
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).
Representativeness
The LABE1 IMPROVE site should be very representative of aerosol
characteristics at Lava Beds Wilderness Area.
Nearby Population/Industrial Centers and Local Sources
The nearest population area and potential source region 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
Nearby meteorological monitoring network stations 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 there. 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
LABE1 and Lava Beds Wilderness Area are 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