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San
Pedro Parks Wilderness Area
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Site Name
IMPROVE:
SAPE1
Region
Southern Rocky Mountains
Terrain
Terrain is shown in the
2 km terrain map and the
20 km terrain map.
San Pedro Parks Wilderness is located in north-central New Mexico just east
of the Continental Divide. It covers 41,132 acres of the Santa Fe National
Forest with a maximum dimension of ten by seven miles. The elevation of the
Wilderness ranges from about 8,500 to over 10,500 feet. It occupies a high,
almost tableland with very few peaks, generally sloping downward from north
to south. It is drained by intermittent and perennial streams extending
downwards on all side, notably the southward flowing Rio Puerco with
headwaters in the Wilderness. Most of the Wilderness is covered with
conifers with aspen and grassland dominating at the higher elevations.
The IMPROVE monitoring site representing the San Pedro Parks Wilderness is
SAPE1, located just outside of the southern Wilderness boundary at an
elevation of 2,919 m (9,574 ft).
Representativeness
The SAPE1 IMPROVE site, with elevation approximating Wilderness elevations,
should be very representative of aerosol composition and concentration at
most Wilderness locations, especially higher elevation locations in the main
central part of the Wilderness.
Nearby Population/Industrial Centers and Local Sources
Nearby Meteorological Data Stations
Nearby meteorological monitoring network stations are shown in the data
network map. Locations and data
from nearby RAWS monitoring sites can also be accessed at the
RAWS station US Climate Archive
website. The
Coyote New Mexico RAWS site, 10 km east of the Wilderness at an exposed
hilltop location is at a similar elevation, 2,683 m (8,800 ft), and should be
quite representative of Wilderness climate and meteorology. Meteorological
data from various New Mexico sites is also available from the
New Mexico Air
Quality Bureau Meteorological Data site.
The San Pedro Parks Wilderness is about 75 miles north of the Albuquerque
RAOB site. Twice daily soundings from Albuquerque should be representative
of upper air structure regionally and within the Wilderness.
Wind Patterns
Albuquerque wind roses show
regional wind patterns. Most of the year but especially in winter there is a
strong northerly component that varies according to the position of the jet
stream. During summer the jet stream migrates further north than usual, so
that synoptic westerly winds aloft are weaker and more southerly winds
dominate, coinciding with the
North American Monsoon.
During this period moisture bearing winds move into the region from the
southwest at the surface, from the Gulf of California, and aloft from the
southeast, from the Gulf of Mexico. Convective instability associated with
surface heating of the moist air, combined with orographic uplift as air is
transported towards higher terrain to the north, produces frequent
convective precipitation events often associated with intense rainfall,
lightning, hail, and damaging winds. Southerly winds may also transport
airborne particulate material into the Wilderness from sources source
regions to the south and southeast, including Mexican sources
Locally, in the absence of strong regional pressure gradients, flows will be
dominated by upslope/downslope winds typical of mountainous areas. Most of
the Wilderness is on elevated terrain with relatively modest relief compared
to most Rocky Mountain locations. Nighttime drainage will tend to flow away
and out of the Wilderness, and daytime upslope flows will generally be from
lower elevations surrounding the Wilderness.
Potential local transport routes into the Gila Wilderness include southerly
and upslope flow via the Rio Puerco valley from source regions to the south,
including the Albuquerque urban area 75 mi away, with pollutants lifted to
Wilderness locations via upslope flow and upwards mixing. Possible more
distant source regions include Mexico and Gulf Coast areas also to the
south.
Inversions/Trapping
Wang and Angell,
1999 describe two regions of the U.S. with high frequencies of regional
stagnation events, in the southwest and south-central U.S. The north central
New Mexico region that includes the San Pedro Parks Wilderness is midway
between these two regions and according to long term data should typically
have one stagnation episode per month from May to October, where an air
stagnation episode is defined as stagnation conditions that persist for 4
days or longer. During this period, pressure and temperature gradients in
the region are weakest, and wind circulations weakest. Subsidence inversions
during these conditions may trap regional haze with buildup over periods of
several days. Since the Wilderness is generally on high terrain with modest
local relief, more local surface based radiation inversions are probably not
as common as in most mountains areas in the Southern Rockies.
Climatological Statistics
Albuquerque
Normals Means and Extremes are representative of regional climatology at
lower elevations. More representative local data can be accessed at the
Coyote New
Mexico RAWS site.
Meteorological Indicators for Local Sources
Keywords
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Last updated 15 November 2004
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