Topoclimatic variations in temperature and
winds as the basis for mountain refugia
C. David Whiteman
University of Utah
Salt Lake City
MtnClim 2014, Midway, UT, 15-18 Sept 2014
Definitions
temperature inversion – an atmospheric layer in which temperature increases with height
lapse rate (LR) – rate at which temperature T decreases with height (–dT/dz)
environmental LR – the actual atmospheric lapse rate (determined from a temperature sounding T(z))
dry adiabatic LR – thermodynamic rate of T decrease when parcel is lifted adiabatically (Γ = -dT/dz = 9.8°C/km)
potential temperature – the temperature Θ a parcel of air would have if brought to 1000 mb (~sea level)
stable layer – an atmospheric layer with a lapse rate less than 9.8°C/km
cold air pool – a terrain-confined atmospheric stable layer
The heat deficit to 2000 m
MSL is proportional to the
area between the
environmental soundings
and the dashed lines
Θ
Local rate of change of potential temperature
Local rate of change of potential temperature gradient
Stability increases when
AWS
Radiosonde
ICs
Tethered balloon
RASS
HOBO T datalogger/
radiation shield
The Salt Lake Basin, Utah
Salt Lake
basin
Three types of SLC cold-air pools
Jan 2004
Craig Clements photo
20 Jan 2005
Jim Steenburgh photo
Erik Crosman photo
Photo Credit: Tom Smart, Deseret Morning News
Relationships between twice-daily heat deficits H22 and daily PM10 and PM2.5 concentrations.
The dashed line marks a threshold heat deficit of 4.04 MJ m-2. PM2.5 and PM10 concentrations
are normalized so that the dashed horizontal line also indicates the NAAQS for these
variables, 35 and 150 mg m-3, respectively.
Whiteman et al. (2014)
Potential temperatures from 12-hourly radiosonde
ascents at Salt Lake City for 2200 m MSL (solid line)
and the surface (dashed line). The shading between
the upper and lower curves is a measure of
atmospheric stability in the valley.
Whiteman et al. (2014)
Lareau et al. (2013)
Lareau et al. (2013)
Lareau et al. (2013)
Lareau et al. (2013)
Lareau et al. (2013)
Lareau et al. (2013)
Lareau et al. (2013)
The mean wintertime heat deficit (1 Oct - 31 Mar) bounces
around from year to year depending on the frequency,
duration and strength of passing high pressure weather
disturbances
Whiteman et al. (2014)
29 Dec 2000 – 9 Jan 2001 SLC cold-air pool
Animation slide 1
Seiches - T oscillations
Columbia Basin
cold pool
Whiteman et al. (2001)
Negative convection, Grand Canyon:
Whiteman et al. (1999)
Pseudo-vertical soundings & superadiabatic profiles
composite: 16,17,18,19,24,25 Jan 2014
Salt Lake Valley
1. Consistent exposure of temperature
sensors, radiation shielding
2. Urban Heat Island (UHI)
3. Cold air intrusions into depressions
UHI
Meteor Crater, AZ
Whiteman et al. (2010)
Gruenloch Sinkhole - Eastern Alps
Steinacker et al. (2007)
Temperature time series - Gruenloch
Dec 1
Dec 4
Dorninger et al. (2011)
Classification of cold pool events
Dorninger et al. (2011)
Basin Meteorology
Whiteman (1990)
Extreme minimum temperatures usually occur in mountain
basins, rather than in valleys:
Peter Sink, UT -69.3°F (-56.3°C) Feb 1, 1985
West Yellowstone, MT -66°F (-54°C) Feb 1933
Taylor Park, CO -60°F (-51°C) Feb 1951
Fraser, CO -53°F (-47°C) Jan 1962
Stanley, ID -54°F (-48°C) Dec 1983
Gruenloch Basin, Austria -63°F (-52.6°C) between 19 Feb and 4 Mar 1932
Cold air pools in valleys
Trappers/drainers:
Whiteman et al. (1996)
Whiteman (2000)
Skyview fraction, dewfall, cooling rates
Multi-sinkholes: Whiteman et al. (2004)
3-D radiative transfer: Hoch et al. (2011)
Cooling rates: DeWekker & Whiteman (2006)
Dewfall: Whiteman et al. (2007)
Kennecott’s Bingham Copper Mine, Utah
Diurnal Mountain Winds
Whiteman (2000)
Review of diurnal mountain wind systems: Zardi and Whiteman (2012)
Cross-valley flows: Lehner et al. (2010); Lehner and Whiteman (2012, 2014)
Slope flows
Whiteman (2000)
Slope winds are gravity or buoyancy circulations following the
dip of the underlying slope and caused by differences in
temperature between air heated or cooled over the mountain
slopes and air at the same altitude over the valley center.
Downslope flows
Animation slide 2
Gruenloch Basin sidewall
2051 UTC 2 June 2002
From R. Steinacker
Whiteman (2000)
Early in the evening when the atmosphere is near-neutral, downslope flows
are strong and they converge on the valley floor. As the ambient stability
(valley inversion) builds later in the evening, the downslope flows cannot
penetrate readily to the valley floor and converge at higher altitudes.
Meteor Crater, Arizona
• Near-circular basin
• Surrounded by a uniform plain sloping
upwards to the SW with 2% slope
• Uniform rim height - no major saddles
or passes
170 m
N
30- 50
m
© John S. Shelton
Propagation of shadows and insolation patterns
Animation slide 3
Meteor Crater, Arizona
Whiteman & Kahler (2006)
Meteor Crater, 0722-0920 MST 20 OCT 2013
Animation slide 4
Meteor Crater, 2220-2320 MST 20 OCT 2013
Animation slide 5
The End
Torres del Paine © Sigrid & Ron Smith
References
• Dorninger, M., C. D. Whiteman, B. Bica, S. Eisenbach, B. Pospichal, and R. Steinacker, 2011: Meteorological events affecting cold-air
pools in a small basin. J. Appl. Meteor. Climatol, 50, 2223-2234.
• Hoch, S. W., C. D. Whiteman, and B. Mayer, 2011: A systematic study of longwave radiative heating and cooling within valleys and
basins using a three-dimensional radiative transfer model. J. Appl. Meteor. Climatol., 50, 2473-2489.
• Lareau, N., E. Crosman, C. D. Whiteman, J. D. Horel, S. W. Hoch, W. O. J. Brown, and T. W. Horst, 2013: The Persistent Cold-Air Pool
Study. Bull. Amer. Meteor Soc., 94, 51-63.
• Lehner, M., and C. D. Whiteman, 2012: The thermally driven cross-basin circulation in idealized basins under varying wind conditions.
J. Appl. Meteor. Climatol., 51, 1026-1045.
• Lehner, M., and C. D. Whiteman, 2014: Physical mechanisms of the thermally driven cross-basin circulation. Quart. J. Roy. Meteor.
Soc., 140, 895-907.
• Lehner, M., C. D. Whiteman, and S. W. Hoch, 2011: Diurnal cycle of thermally driven cross-basin winds in Arizona's Meteor Crater. J.
Appl. Meteor. Climatol., 50, 729-744.
• Steinacker, R., C. D. Whiteman, M. Dorninger, B. Pospichal, S. Eisenbach, A. M. Holzer, P. Weihs, E. Mursch-Radlgruber, and K.
Baumann, 2007: A sinkhole field experiment in the eastern Alps. Bull. Amer. Meteor. Soc., 88, 701-716.
• De Wekker, S. F. J., and C. D. Whiteman, 2006: On the time scale of nocturnal boundary layer cooling in valleys and basins and over
plains. J. Appl. Meteor., 45, 813-820.
• Whiteman, C. D., 1990: Observations of Thermally Developed Wind Systems in Mountainous Terrain. Chapter 2 in Atmospheric
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Processes Over Complex Terrain, (W. Blumen, Ed.), Meteorological Monographs, 23, no. 45. American Meteorological Society,
Boston, Massachusetts, 5-42.
Whiteman, C. D., 2000: Mountain Meteorology: Fundamentals and Applications. Oxford University Press, New York, 355pp.
Whiteman, C. D., S. W. Hoch, J. D. Horel, and A. Charland, 2014: Relationship between particulate air pollution and meteorological
variables in Utah's Salt Lake Valley. Atmos. Environ., 94, 742-753.
Whiteman, C. D., S. W. Hoch, M. Lehner, and T. Haiden, 2010: Nocturnal cold air intrusions into Arizona's Meteor Crater:
Observational evidence and conceptual model. J. Appl. Meteor. Climatol., 49, 1894-1905.
Whiteman, C. D., S. F. J. De Wekker, and T. Haiden, 2007: Effect of dewfall and frostfall on nighttime cooling in a small, closed basin.
J. Appl. Meteor., 46, 3-13.
Whiteman, C. D., T. Haiden, B. Pospichal, S. Eisenbach, and R. Steinacker, 2004: Minimum temperatures, diurnal temperature ranges
and temperature inversions in limestone sinkholes of different size and shape. J. Appl. Meteor., 43, 1224-1236.
Whiteman, C. D., S. Zhong, W. J. Shaw, J. M. Hubbe, X. Bian, and J. Mittelstadt, 2001: Cold pools in the Columbia Basin. Weather and
Forecasting, 16, 432-447.
Whiteman, C. D., S. Zhong, and X. Bian, 1999: Wintertime boundary-layer structure in the Grand Canyon. J. Appl. Meteor., 38, 10841102.
Whiteman, C. D., T. B. McKee, and J. C. Doran, 1996: Boundary layer evolution within a canyonland basin. Part I. Mass, heat, and
moisture budgets from observations. J. Appl. Meteor., 35, 2145-2161.
Zardi, D., and C. D. Whiteman, 2012: Diurnal Mountain Wind Systems. Chapter 2 in: Mountain Weather Research and Forecasting
(Chow, F. K., S. F. J. DeWekker, and B. Snyder (Eds.)). Springer, Berlin, pp 35-119.