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Mesa
Verde National Park
Site Name
IMPROVE: MEVE1
CASTNET: MEV405
Region
Colorado Plateau
Terrain
Terrain is shown in the 2 km terrain
map and the 20 km terrain
map.
Mesa Verde National Park is located
in southwestern Colorado. Terrain is essentially a large mesa, tilted
slightly with its lower terrain towards the south, cut with numerous north
to south oriented drainages with depths on the order of 150 m (500 ft) below
mesa top elevations. As with the lift of the land, all drainages are toward
the south into the Mancos River canyon, which in turn drains to the
southwest to the Colorado River. The north side of the mesa is a bluff that
drops from highest north mesa elevations near 2,600 m (8,500 ft) to near 2,100
m (6,900 ft) in a distance of a little over 1 km (0.6 mi). The
IMPROVE monitoring
site, MEVE1, is at an exposed location on the top of the mesa, elevation
2,177 m (7,141 ft), near the center of the Park. Ground cover in the vicinity
is Juniper forest.
Representativeness
Aerosol data collected at MEVE1 should be very representative of vistas
overlooking the Park.
Nearby Data Stations
Meteorology has been monitored at the
CASTNET Mesa Verde NP site, MEV405, since 1995. Data from this
monitoring site should provide the best available representation of
meteorology and climate of the Park. Measurements include wind speed, wind
direction, stability, temperature, and relative humidity. Other nearby
monitoring network stations are shown in the data network
map
and at the US Climate
Archive and RAWS station US
Climate Archive sites. The nearest upper site with measurements
representative of upper air structure at Mesa Verde NP is Grand Junction,
Colorado.
Wind Patterns
Mesa Verde wind roses are based on surface meteorological data collected at
the Mesa Verde CASTNET site, MEV405, for the period 1995 – 2001 and indicate
annual and seasonal wind direction (direction from which the wind is
blowing) frequencies. Annual and seasonal wind roses should represent
exposed locations at higher elevations. At lower canyon elevations winds may
be steered more in line with the terrain orientation. Prevailing wind
directions are predominantly northerly, with additional southerly flow in
the summer. Nighttime (0100 – 0600) and daytime (1300-1700) annual wind
roses show a diurnal pattern. Nighttime drainage flow is from the higher
Mesa elevations in the north toward the Mancos River drainage in the south.
Daytime directions are southerly to westerly to northerly, a combination of
upslope local flow and west to north synoptic flow.
Potential transport routes into Mesa Verde NP include low-level transport
into the area via the Colorado and Mancos River drainages, with upward
convective and upslope mixing to higher elevations, and upper air transport
via upward mixing in distant source regions and advection aloft into Park
areas.
Inversions/Trapping
At mesa top locations, inversions will not be trapping inversions of the
sort that occur in deep valleys and canyons, but subsidence inversions that
become established as air subsides over a surface high pressures area and
are associated with buildup and stagnation of synoptic high pressure ridges.
These are most likely to occur during the extended summer (May - October),
when pressure and temperature gradients in the region are weakest, and wind
circulations therefore weaker. During these conditions aerosol concentration
and composition should be uniform within the park.
Lower park elevations in the numerous canyons and washes have bottom
elevations typically 150 m (500 ft) or less below mesa top locations, with
egress into the Mancos River canyon and Colorado River drainage. Trapping
radiation inversions may occur in these canyons and washes in fall and
winter but would not extend vertically to mesa top locations.
Climatological Statistics
Climate statistics can also be retrieved from
CASTNET data for Mesa Verde, site
MEV405, from which the Mesa Verde wind roses were derived. Regional normals,
means and extremes for the
Grand Junction
NWS station should be reasonably representative of Mesa Verde National
Park.
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Updated 9 January 2007
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