]
United States Environmental Sciences Resea^n
Environmental Protection Laboratory
Agency Research Triangle Park NC 27711 June 1980
Raiaarch and Development
Observations of Flow
Around Cinder Cone
Butte, Idaho
For Internal Use Only
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OBSERVATIONS OF FLOW AROUND CINDER CONE BUTTE, IDAHO
by
William H. Snyder
Meteorology & Assessment Division
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Robert E. Lawson, Jr.
Northrop Services, Inc.
Research Triangle Park, NC 27709
Roger S. Thompson
Meteorology & Assessment Division
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
and
George C. Holzworth
Meteorology & Assessment Division
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
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ACKNOWLEDGMENTS
Our appreciation is extended to C. Ray Dickson and crew from the
National Reactor Test Station in Idaho Falls, ID for their willing par-
ticipation and competent service. Our thanks are also extended to
others of the FMF staff who assisted in the preparations for the study,
and especially to Myron Manning, who was primarily responsible for the
assembly of 800 orange smoke candles (in spite of the fact that, due to
circumstances beyond our control, the candles never reached their final
destination).
IV
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SECTION 1
INTRODUCTION
A preliminary one-week study of the flow over Cinder Cone Butte was
conducted in order to determine the suitability of the site for later, more
extensive studies of transport and diffusion over a small, isolated hill and
to perform a preliminary evaluation of the significance of various parameters
on the flow structure. A large smoke generator was used to obtain streamline
and diffusion patterns over the hill. Smoke candles were used to obtain sur-
face streamline patterns and, in conjunction with a tethered kytoon, elevated
releases. Limited measurements of wind speed and direction as well as tempera-
ture were made to characterize the stability of the approach wind. An attempt
was also made to measure katabatic winds through the use of highly sensitive
plate anemometers.
The primary aim of the 100 m hill study is to learn what mechanisms affect
plume impingement on elevated terrain and thereby to enable the construction
of mathematical models to predict the occurrence and duration of plume impinge-
ment and the resulting time-averaged surface concentrations. To this end, it
was of greatest interest to conduct the field experiments during periods of
strong stable stratification, i.e., primarily light-wind, cloudless, night-
time and early morning hours. The weather conditions during this preliminary
one-week period, however, were not conducive to the development of strongly
stable stratification; the entire period may be characterized as high-wind,
overcast, near adiabatic. There was, however, one evening period of a few
hours when the sky was clear and the winds were light, and during this period,
very interesting observations were made that allowed us to draw conclusions
concerning katabatic winds and stable plume impaction. Since we were, in fact,
interested in plume behavior under all weather conditions, flow patterns were
also observed during the high-wind, neutral time periods, and some useful
conclusions are drawn concerning separation on the lee side of the hill,
present under certain conditions and absent in others.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
Because of the qualitative nature of the study, it is difficult to
draw firm conclusions concerning the flow structure over the hill. Never-
theless, the observations and limited quantitative data collected are not
inconsistent with the following speculative statements.
1. Under neutral conditions, plumes from upwind sources will be spread
thinly to cover large areas of the hill surface; this is contrary to
flow over two-dimensional hills where streamline displacement is
substantially larger.
2. A slope greater than 15° is required to force flow separation on the
lee slope of an axisymmetric hill under neutral conditions. A smooth
hill with a rounded top and lee slope of 25° will exhibit inter-
mittent flow separation. A salient edge will fix the separation
point on such a hill, so that a semi-permanent recirculating region
is formed. The extent of this recirculating region will be much
smaller both in the normal and along-slope dimensions in comparison
with that on a two-dimensional hill.
3. Stable plume impingement, as evidenced in laboratory studies, will
occur under light wind, strongly stable approach flows.
4. Katabatic winds are formed on a 100 m hill and could significantly
influence surface concentrations from an impinging plume. Moderate
wind speeds (> 4 m/s) in the approach flow, however, may destroy
these katabatic winds.
Concerning the suitability of the site for later, more extensive studies,
Cinder Cone Butte is ideal in several respects:
1. It is the overwhelmingly predominant terrain feature for many kilo-
meters in any direction, being situated in the broad Snake River
Basin. There are only two much smaller buttes (less than 20 m in
height) within a 2 km radius, and neither of these is aligned with
the predominant wind directions of SE or MW.
2. There is good access to the base of the hill with many roads, espe-
cially on the south side. Additional roads or 4-wheel-drive vehicles,
however, are needed for closer access on the north side. There is
access to the top of the hill, where electricity, a tower and a small
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building may be accessible.
3. The 100 m height appears large enough to induce katabatic winds, yet
it is small enough to avoid formidable logistics problems.
4. The sjTape_ of the hill (different slopes on different sides) allows
study of separated and non-separated flows at the same site.
5. Although not discussed in the present report, meteorological condi-
tions favorable to stable plume impingement appear to be relatively
abundant, especially in the fall of the year.
The following observations and suggestions are offered as an aid to the
design of future studies to be conducted at Cinder Cone Butte. They are by
no means intended to be a comprehensive set:
1. At least one 150 m tower positioned NE or SW of the hill and instru-
mented at 8 to 10 levels for temperature and three-dimensional winds
is essential for characterization of the approach wind structure.
Real-time feedback and display of all meteorological data are
essential for decision-making on where and how high to place the
tracer-source on a 15 to 30 minute time scale.
2. Because katabatic winds could be important, the hill should be
instrumented to measure them, presumably with a fairly dense network
of short towers (less than 10 m in height). The most likely time
period for the occurrence of katabatic winds is a few hours after
sunset, and tracer-releases should be planned for this period. Be-
cause of the rugged terrain, real-time feedback of data on katabatic
winds to a central station is imperative.
3. The tracer should be released from a tall (about 80 m) mobile crane.
The kytoon release system was inadequate because the kytoon meandered
widely, lifted only a small payload, and could not be flown in high
winds, a not infrequent occurrence in Idaho. Peripheral roads could
easily be cut around the base of the hill to provide rapid mobility
for the crane.
4. The hill should be "covered" with concentration detectors and, again,
real-time feedback is highly desirable.
5. One problem that was not anticipated was that of orientation; it was
difficult to precisely locate a particular point on the map. This
problem would best be solved by surveying the hill and partitioning
it with appropriate highly visible markers.
6. In spite of the small size of the hill, one of the most serious pro-
blems was the amount of time required to complete various tasks, pri-
marily due to our limits of physical endurance. This problem could
be overcome by better organization, remote stations with data being
transmitted to a central facility, and possibly with all-terrain
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(one-man type) vehicles.
Colored smoke was highly superior to white in visibility, even though
the release rates of colored smoke were at least an order-of-magnitude
lower than those of the white smoke. Subjective judgements indicated
that orange would be the best color to photograph against a background
of blue or cloudy sky and dark green was highly visible against the
yellowish-brown surface cover.
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SECTION 3
EXPERIMENTAL DETAILS
SITE DESCRIPTION
The site, Cinder Cone Butte, is located in the broad Snake River Basin
in southwestern Idaho, approximately 30 miles south-southeast of Boise and
15 miles northwest of Mountain Home Air Force Base. It is the predominant
terrain feature for many miles in any direction (see Figure 1).
Cinder Cone is 100 meters high; the base is nearly circular with a diam-
eter of 1 km; it has nearly twin peaks, separated in the north-south direction
by 200 meters. Slopes on all sides approach 25°. A paved (secondary) road
provides access to the peaks. There is a 61 m microwave communications tower
2
(FAA) on the northern peak and a 22 m cinder block building (Idaho National
Guard) about 150 m northwest of the southern peak. Hereafter, the building
will be referred to as the "bunker", the northern peak as the Tower Knoll,
and the southern peak as the Boundary-Marker Knoll, since the USGS has placed
a permanent marker on this the higher of the two peaks (by approximately 8
meters).
The predominant wind direction is southeast, with a secondary maximum
of northwest. The surrounding terrain within 10 km of the hill has a gradual
slope of 3.6 m/km, downward toward the southeast; the Snake River Basin, how-
ever, generally slopes downward toward the northwest. The variation in ele-
vation of the terrain within a 3 km radius of the hill is less than ± 5 m,
except for two isolated buttes: one is 20 m high and located 2 km WNW of
Cinder Cone; the other is 16 m high and located 3 km SW. Neither of these
smaller buttes is expected to significantly affect the flow patterns, i.e.,
Cinder Cone may be regarded as an isolated hill.
There are numerous roads around the base of the hill, especially on
the south side; additional roads or 4-wheel-drive vehicles are necessary for
closer access to the north and east sides. There is a cinder pit on the
south side of the hill, perhaps 300 m long and 150 m wide. Whereas the pit
is somewhat undersirable from a fluid mechanics viewpoint, its existence is
not regarded as a serious deficiency; indeed, the flat barren floor provides
a useful staging area for large equipment.
The eastern slope of the hill is covered by long grass (25 cm) except
for rather large (3 m) rock outcroppings near the top (% 75 m elevation).
The remainder of the slopes as well as the surrounding flat terrain to the
north, west and south are covered rather densely by 50 cm high sagebrush.
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The terrain east of the hill is primarily agricultural and, during this
period, the fields were either plowed or covered with 10 cm crop stubble.
Figure 2 shows the profile of the hill and surrounding terrain from a
viewpoint approximately 1 km southwest of the hill.
APPARATUS AND INSTRUMENTATION
A Climatronics cup and vane anemometer was mounted at the 15 m level of
the FAA tower to monitor hi 11-top wind speed and direction. An aspirated
temperature sensor was mounted at the 10 m level on the same tower. Strip
chart and magnetic tape recordings of wind speed and direction and temperature
were made continuously from noon Hednesday, Jan. 9 through 0900 Saturday,
Jan. 12.
A 10 m-tower (see Figure 2) was erected approximately 1.2 km southwest
of the hill center. This tower was instrumented with cup and vane anemo-
meters at the 2 and 10 meter levels and with aspirated temperature sensors
at the 2, 5 and 10 m levels. Continuous strip chart recordings of all 5
variables were made from 1530 Tuesday, Jan. 8 through 1400 Friday, Jan. 11.
It was supposed that the characteristics of the approach wind were represented
by the measurements at this site.
3
A tethered 17 m helium-filled kytoon instrumented with a wiresonde
was used to measure vertical temperature profiles. The kytoon was also used
on one occasion to raise smoke candles to various levels to photograph ele-
vated plumes released upwind of the hill.
Five-minute white smoke candles were placed at various points around
the hill for photographing surface flow patterns; they were also raised by
the kytoon for the elevated releases. One-minute smoke candles of various
colors were used to observe the behavior of the separated flow in the lee
of the hill.
A truck-mounted smoke generator was used to produce large volumes of
white smoke. This smoke generator was a turbine engine in which "corvus"
oil was injected into the hot exhaust manifold. A photograph of the smoke-
truck and kytoon in the cinder pit is contained in Figure 3. Color-slide,
black-and-white, and motion picture film were used to photograph the plume or
smoke behavior.
Specially-constructed swinging-plate anemometers were installed in an
attempt to measure downslope or katabatic winds. They consisted of light-
weight (balsa wood) plates, 10 cm x 20 cm, suspended on hinged arms (see
Figure 4). Wind-tunnel calibrations had shown that the range of these instru-
ments was 0.5 to 4 m/s, i.e., deflection angles varied from 2° at 0.5 m/s
to 85° at 4 m/s with a horizontal wind. Further testing had been done
with an inclined wind tunnel to determine their response as a function of
slope angle. Twelve of these plate anemometers were placed as shown in
Figure 5 (sites 1 through 12), with the plates approximately 1 m above the
ground surface. The sites were located using a compass, a rangefinder and
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a coordinate system based on the top of the FAA tower. Each anemometer also
contained a lightweight paper streamer to indicate the wind direction. The
anemometers were read by rotating the arm holding the plate and streamer
until the arm (hence, plate) was perpendicular to the streamer (hence, wind
direction). At this point, the wind direction was read on a (previously
aligned) protractor and the plate deflection angle was also noted. This
system was, of course, rather crude, as wind direction and speed fluctuated
considerably at times; in general, however, wind direction readings were
felt to be within ± 15° and speeds within + 0.5 m/s, which should have been
sufficient to determine the presence or absence of katabatic winds.
Wind profiles were measured with a TALA (tethered aerodynamically lifting
anemometer) manufactured by Approach Fish, Inc. This instrument is basically
a precision-manufactured kite where the wind speed is obtained through measur-
ing the force on the tether line with a spring-scale, the elevation of the kite
is calculated from the line length and elevation angle, and the wind direction
is, of course, the azimuthal angle of the kite, which is sighted with a compass.
The data reported herein represent approximately 2-minute averages at each
elevation.
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SECTION 4
PRESENTATION AND DISCUSSION OF RESULTS
It is convenient to divide the study duration into 5 distinct periods,
in each of which the meteorological conditions can be regarded as stationary
or slowly changing.
Period I, lasting from 1415 to 1600 MST on Jan. 9, may be characterized
by moderate wind speeds of 6 m/s at the 10 m tower and 9 m/s at the hill
top (see Figures 6 and 7). Wind directions were Quite steady from the south-
east (±5°). A much earlier temperature profile (1205 MST at the cinder pit)
showed a temperature inversion existing to at least 2 hill heights, but during
the smoke releases (Period I), the profiles were closer to neutral (see Figure
8). The 15-minute average temperature differences between the two towers
(Figure 6) were, in fact, of the opposite signs from those measured by the
wiresonde (Figure 8). This is possibly due to the different averaging
periods and time-varying surface heating caused by the sun above the nearly
overcast sky. In fact, the wiresonde data (Figure 8) show a super-adiabatic
lapse rate near the surface, but convective plume behavior from the surface
smoke source was not observed. Also, the FAA tower temperature was probably
not representative of the approach flow temperature at the same elevation
upstream (see later discussion). The Froude number based on the average
gradient over the depth of the hill was 3 < Fr < 8, weakly stable. (Fr = U/Nh,
where U is a representative flow speed, N is the Brunt-Vaisala frequency (see
later discussion), and h is the hill height.)
Smoke was released from the truck positioned upwind of the hill (Figure
9) and near the top of the lee slope (Figure 10). Photographs were taken
from near the tower southwest of the hill (see Figure 11). Figures 9 and
10 show quite clearly that the plume was transported over the hill top and
down the lee side without separating. It is clear that the FAA tower tem-
perature is probably more closely related to the 10 m than to the 107 m
approach flow temperature because the streamlines pass over the hill top.
The upwind streamline behavior expected from the towing tank observations
of Hunt et al (1978) or Hunt and Snyder (1980) is for all streamlines to
pass over the hill top for Fr > 1. On the other hand, separation of the flow
on the lee side was observed for Fr > 1 by Hunt and Snyder (1980) for a hill
of maximum slope near 45°. But the lee slope of Cinder Cone for this wind
direction was only 15° and, as pointed out by Snyder et al (1979), separa-
tion is not necessarily expected for hills of lower slope. This is clearly
a two-parameter problem, where separation is determined by a slope parameter,
say h/L, as well as the ratio (x/4L) of the wavelength of the fundamental
lee wave mode (A) to the overall length of the hill (4L). (L is defined as
the half-length of the hill (radius) at the half-height point (see Snyder
8
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et al, 1980); x = 2-irU/N, where U is the mean flow speed and N is the Brunt-
Vaisala frequency (=((g/p)dp/dz)^)). Separation may be expected to occur if
the slope is large enough and if x » 4L. In the present case, x was 2 to 5
times larger than 4L. Hence, because of the very limited amount of data, it
is not possible to determine whether separation was absent because (a) the
slope was too small (in which case, the flow would not separate even in neutral
conditions) or (b) it was suppressed by the stratification. Observations
under strictly neutral conditions would be required to fully understand the
results.
Figure 12 shows surface flow patterns made visible by smoke candles
placed at various elevations on the southwest slope, quite close to the line
formed by plate-anemometer sites 7, 8 and 9. These surface flow patterns
were photographed from a point north of the 10 m tower, i.e., west-southwest
of the hill (see Figure 11). Again, the non-separated character of the flow
is evident.
Period II, lasting from 1300 to 1615 MST Thursday, Jan. 10, may be char-
acterized by strong winds from the west-northwest. Wind speeds were quite
steady at about 9 m/s at the lower levels and 18 m/s at the hill top (see
Figure 13). Sky cover was essentially clear at the beginning of the period
and completely overcast by the end of the period. Because of the strong
winds, it was not possible to obtain wind or temperature profiles with the
kytoon, but with the high winds, it is safe to assume the stability was close
to neutral.
Figure 14 shows the surface flow pattern on the lee side of Tower Knoll,
with separation occurring at the salient edge created by the rock outcropping.
The surface flow is UJD the slope, in the opposite direction from the approach
winds. This photograph was taken from the Boundary-Marker Knoll; the smoke
was created with a one-minute, green smoke bomb. Intermittent separation was
also observed on the lee side of Boundary-Marker Knoll, where the slope is as
steep as on Tower Knoll (^ 25°), but there was no salient edge to fix the
location of the separation point, i.e., the hill curvature was quite smooth
(see Scorer, 1968).
In Figure 15, the smoke truck was positioned on top of Tower Knoll.
Photographs were taken from a position northeast of the hill (see Figure 11).
The plume from the smoke-truck obviously separated from the lee side of the
hill. In Figure 16, the smoke-truck was positioned in the trough extending
eastward between the two knolls. It was hidden from the camera, but its
location was directly behind the observer standing at the arrow placed on the
photograph. The separated flow was observed to travel up the slope (careful
examination shows it travelling nearly to the rock outcropping) before it
was entrained by the northwesterly flow above. When the smoke-truck was
positioned on the small mound on the left side of the photograph, the smoke
was observed to flow toward the left (toward the southeast) continuously.
Thus, the reattachment point was located upwind of the base of the hill; the
separated flow region was evidently quite shallow in vertical extent and
quite limited in length along the lee slope.
It would appear, then, that a lee slope of near 25° is required to obtain
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separation under neutral conditions unless a salient edge exists to force
separation to occur. This is somewhat contrary to the results of Khurshudyan
et al (1979) where, for a smooth, rounded two-dimensional hill with a maximum
slope of 26° in a wind tunnel, separation was definitely observed on the lee
side. (Intermittent separation was observed on a hill with maximum slope
of 16°.) The critical slope for separation to occur, however, is most
likely a function of the two-dimensionality, with steeper slopes required
for separation to occur on axisymmetric hills. Eliseev (1971) also showed
separation on the lee side of a 100 m, three-dimensional hill, where the lee
slope was about 30°, presumably under neutral conditions.
Period III, lasting from 1800 MST, Thursday, Jan. 10 through 0100 MST,
Friday, Jan. 11, was characterized by light winds and clear skies. It is
convenient to divide this period into three subperiods. Period Ilia, just
after sunset, may be characterized as near-calm, with wind speeds generally
less than 2 m/s, even on the FAA tower, and wind directions meandering widely
(see Figure 17). During this period of time, plate anemometers were being
set-up at sites 7 through 12. Whereas "official" readings were not made at
this time, steady downslope winds of order 2 m/s were noted at each of the
sites. It is also of interest to surmise a growing surface inversion layer
from Figure 17, where around 1900 MST the 2 m temperature dropped sharply
from the 10 m temperature and around 1930 MST, the 10 m temperature dropped
sharply from the FAA tower temperature.
By Period IHb, 2130 to 2300 MST, the winds had increased somewhat
to 3 to 4 m/s, even stronger at the hill top, and the wind direction settled
to quite-steady easterly. During this period, readings were made at all
12 plate-anemometer sites. The results are shown in Figure 18. The upper-
level sites showed little evidence of katabatic winds, as might be expected
since the upper-level approach winds were around 3 to 5 m/s. The lower two
levels of sites, however, all showed significant downslope components, gener-
ally between 1 and 2 m/s. We conclude that katabatic winds are generated on
this 100 m hill and later efforts should be prepared to measure its structure.
Unfortunately, we were unable to obtain any estimates of the thickness of the
katabatic wind layer.
During Period IIIc, upper level winds had picked-up to 7 m/s, apparently
decoupling from the surface winds of about 2.5 m/s, and the directions at both
levels shifted to slightly south of due-east. The temperature records (Figure
17) showed a strong temperature difference over the height of the hill,
and, from the previous trends, we may speculate that a quite strong, surface
based inversion existed with a top near mid-hill height. A smoke candle
set-off at site 13 showed surface winds in the trough between the knolls
travelling up the slope at quite a high speed (see Figure 19). Releases
near site 14 and north of site 15 (Figure 19) showed that the plume first
traveled toward the east, counter to the approach wind, then around the north
side of the hill at nearly constant elevation. This behavior, though not fully
substantiated, is in qualitative agreement with the dividing-streamline concept
for strongly stable flows advanced by Hunt et al (1978). Plumes above such
a dividing streamline in the approach flow have sufficient kinetic energy to
overcome the potential energy required to surmount the hill crest whereas
those below the dividing streamline must pass round the sides.
10
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Period IV is conveniently divided into two subperiods. Period IVa,
lasting from 0900 to 0930 MST, Friday, Jan. 11, was characterized by moderate
winds of 5 m/s at the lower levels and 10 m/s on the FAA tower (Figure 20).
The wind direction shifted during this short period from southerly to south-
easterly. An earlier temperature profile (Figure 8) showing a sharp elevated
inversion at 70 m is suspect because of the sharp superadiabatic layer at
110 m. The best estimate is "near-adiabatic", at least to the top of the hill.
Clouds moved in rapidly (from the west) during this period so that the sky was
completely overcast by 0930 MST. Wind speeds were changing too rapidly to
obtain useful profiles from the TALA (Figure 7).
Figure 21 shows elevated releases from the smoke candles suspended
from the kytoon. This photograph was taken from a point approximately
1.5 km southeast of the hill center (see Figure 11). The neutral plume was
observed to approach the hill surface quite closely. It converged in the
vertical and diverged in the lateral direction as it encountered the hill
and spread thinly to cover a broad area of the hill surface. This physical
picture is consistent with the predictions of Hunt et al (1979), where it
is shown that the center!ine of a plume approaches the surface of a three-
dimensional hill much more closely than it does a two-dimensional one.
During Period IVb, from 1000 to 1100 MST, Friday, Jan. 11 (see Figure 20)
the winds were even stronger, 9 m/s at the lower levels and 18 m/s near the
hill top. In fact, dust was swept up by the surface winds over broad areas
of the agricultural fields to the southeast of the hill. The 15 minute-mean
wind direction was quite steady, but shorter period fluctuations were large,
i.e., in the range of ± 20°. The plume from the smoke truck was spread widely
in the lateral direction to cover most of the hill surface with a thin layer
of smoke (Figure 22). Again, a view from the southwest (not shown here) showed
that the flow down the lee slope did not separate. Because of the much larger
wind speeds (compared with Wednesday, Jan. 9) and the near adiabatic tempera-
ture profile measured earlier, it is nearly certain that the approach wind
was of neutral stability. Thus, we may conclude that a 15° slope is in-
sufficient to force separation on a three-dimensional hill under neutral con-
ditions.
11
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REFERENCES
1. Eliseev, V.S., 1973: Stereophotogrammetri c Investigations of the Air Flow
in the Boundary Layer of the Atmosphere above a Hill, Air Pollution a_nd
Diffusion (M.E. Berlyand, ed.), J. Wiley & Sons, NY, p. 95-108.
2. Hunt, J.C.R., Puttock, J.S. and Snyder, W.H., 1979: Turbulent Diffusion
from a Point Source in Stratified and Neutral Flows around a Three-Dimen-
sional Hill: Part I: Diffusion Equation Analysis, Atmos. Envir., v. 13,
p. 1227-1239.
3. Hunt, J.C.R. and Snyder, W.H., 1980: Experiments on Stably and Neutrally
Stratified Flow over a Model Three-Dimensional Hill, J. Fluid Mech., v. 96,
pt. 4, p. 671-704.
4. Hunt, J.C.R., Snyder, W.H., and Lawson, R.E., Jr., 1978: Flow Structure
and Turbulent Diffusion around a Three-Dimensional Hill: Fluid Modeling
Study on Effects of Stratification: Part I: Flow Structure, Envir. Prot.
Agcy. Rpt. No. EPA 600/4-78-041, Research Triangle Park, North Carolina,
84 p., July.
5. Khurshudyan, L.H., Snyder, W.H. and Nekrasov, I.V., 1979: Flow and Dis-
persion of Pollutants over Two-Dimensional Hills: Summary Report on Joint
Soviet-American Study, Unpublished Rpt., Envir. Prot. Agcy., Research
Triangle Park, North Carolina.
6. Scorer, R.S., 1968: Air Pollution. Pergamon Press., NY, 151 p.
7. Snyder, W.H., Britter, R.E. and Hunt, J.C.R., 1979: A Fluid Modeling
Study of the Flow Structure and Plume Impingement on a Three-Dimensional
Hill in Stably Stratified Flow, Preprints Vol. I, Fifth Int. Conf. on
Wind Engr., July, 8-14, p. III. 10. 1-11, Colorado State University, Fort
Collins, Colorado.
12
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Figure 2. Profile of Cinder Cone Butte Viewed from 10 m Tower 1.2 km
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Figure 3. Smoke-Truck and Kytoon in Cinder Pit,
- 14 -
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- 15 -
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PERIOD I
o-
u
o -,
o 7
Sr 6
I- c
<3
cc
I I I
0 c
)
— O O O o O o
O O x\ o o o
— v o
. o o o o o u
I To 0 ° 0 o 0 ° OAVGOF2&10m
g 3V_0 000 0 FAA TOWER
H 7l III
v w _
^^^™
1100
1200
1300 1400
TIME of DAY
1500
1600
Figure 6. Wednesday, January 9, 1100 to 1600 MST. 2 m and 10 m values are
for Dickson's tower location. Where the temperatures at 2 m and
10 m were nearly identical an average is shown. Each data point
represents a 15-min. average.
- 17 -
-------
I
u
175
150
125
100
75
50
25
0
175
1115-1130 Hr JAN. 9
1520-1615 Hr JAM 9
0835-0930 Hr JAN 11
60 80 100 120 140
WIND DIRECTION, deg.
160 180 200
6.0 7.5 9.0 10.5 12.0 13.5 15.0 18.5
WINDSPEED. m/sec
Figure 7. Wind speed and direction profiles from TALA,
- 18 -
-------
20
0
A|1205, JAN. 9
• 1526, JAN. 9
• 0816, JAN. 11
-7.5 -6.0 -4.5 -3.0 -1.5 0 1.5
TEMPERATURE, °C
3.0 4.5
6.0
Figure 8. Temperature profiles from wiresonde.
- 19 -
-------
Figure 9. Jan. 9 Smoke Plume - Truck Upwind.
Figure 10. Jan. 9 Smoke Plume - Truck Near Hill Top on Lee Side.
- 20 -
-------
200 400 600 800 1000
SCALE, meters
LEGEND ,'/ '••-. j
ST = SMOKE TRUCK
C=CAMERA
K = KYTOON
T=TOWER ,
A= BOUNDARY MARKER
NUMBERS FOLLOWING CODES REFER TO FIGURES
Figure 11. Camera, smoke truck and kytoon locations.
- 21 -
-------
Figure 12. Jan. 9 Surface Smoke Streamers
- 22 -
-------
d) 360
0)
-a
2 340
o 320
£ <
0 300
0
z
g 280
1 1 1
— 1 1
— o o o— {
— ooo°oo°oo a —
ho0ooooooo g —
_-° 0 0 IS t}BSA@@@@a0 QQ
' A H id A A
o -•
— — . i j -
PERIOD
rT3000oo0000000000
A A
u D
A A
o
A A A
o
o
o°
ULJ"
CC
13
cr
LU
a.
^
LU
1
0
_ i i
A 2m
D 10m
0 FAA TOWER
O AVG OF2& 10m
>X> O 0 o o c
,h T i
I ! _
-
o ° —
^0^0° *«&£;
i i -
1100 1200 1300 1400
TIME OF DAY
1500
1600
1700
Figure 13. Thursday, January 10, 1100 to 1700 MST. 2 m and 10 m values
are for Dickson's tower location. Where the temperatures at
2 m and 10 m were nearly identical an average is shown.
- 23 -
-------
Figure 14. Separation at Rock Outcropping on Lee Side of Tower Knoll
Approach Winds from Left to Right.
- 24 -
-------
Figure 15. Flow Separation on Lee Side of Hill - Smoke Truck on Top of
Tower Knoll.
Figure 16. Recirculation Region on Lee Side of Hill - Smoke Truck in Trough
behind Arrow.
- 25 -
-------
300
DC
UJ
Q.
5
UJ
, opn
1*SS8°|°ogooo0
A 2m
i r
O FAA TOWER
OAVGOF2& 10m
°0°
-6
-8
1700 1800 1900 2000 2100 2200 2300 2400 0100
TIME of DAY
Figure 17. Thursday, January 10, 1700 to 2345 MST and Friday, January 11,
0000 to 0100 MST. 2 m and 10 m values are for Dickson's tower
location. Where the temperatures at 2 m and 10 m were nearly
identical an average is shown.
- 26 -
-------
THURSDAY, JANUARY 10, 2130 - 2300 HR.
0 1 2
0
WINDSPEED SCALE, m/sec
200 400 600 800 1000
SCALE, meters
Figure 18. Surface winds observed on night of January 10.
- 27 -
-------
0
WIND DIRECTION: 110°
WIND SPEED-
SURFACE: 2.5 m/s
HILLTOP: 7.0 m/s
200
Figure 19. Behavior of plumes from surface smoke releases near midnight, Jan. 10.
- 28 -
-------
IV-a
S» 180
•O
Ml ^
I- ,
o 140'
GC
Q 120
G
^ 100
25
0
0)
i 20
Q 15
LU
LU (
0. 10
CO
Q
2 51
3
u ^
o 2
LU 1
D 0
-A ^ ft i
F* • t
— A 2m
— • 10m
— • FAA TOWER
I
1
— A 2m
~~ • 10m
_ • FAA TOWER •
!-•••*••
w
. _ •
»-••••••
1
1
IV-b
' -
—
• I i t t •-
—
—
^^~
_
• •
. • • • =
m
H H ™
•-'"
^-~
1
_ • AVGOF2 AND 10m
_ • FAA TOWER
— A ^
. „
.,«t:$=
Li
-2
-3
-5
0800
0900 1000
TIME of DAY
1100
Figure 20. Friday, January 11, 0800 to 1115 MST. 2 m and 10 m values
are for Dickson's tower location. Where the temperatures
at 2 m and 10 m were nearly identical an average is shown.
- 29 -
-------
Figure 21. Elevated Smoke Release at 9:15 am, Jan. 11 (clock time is
incorrect).
Figure 22. Smoke Truck Release at 10:30 am, Jan. 11 (clock time is
incorrect).
- 30 -
------- |