Abstract
During a haze event in Baltimore, U.S.A. from July 6 to 8, 2002, smoke from forest fires in the Québec region (Canada), degraded air quality and impacted upon local climate, decreasing solar radiation and air temperature. The smoke particles in and above the atmospheric boundary layer (ABL) served as a tracer and provided a unique opportunity to investigate the ABL structure, especially entrainment. Elastic backscatter lidar measurements taken during the haze event distinctly reveal the downward sweeps (or wisps) of smoke-laden air from the free atmosphere into the ABL. Visualisations of mechanisms such as dry convection, the entrainment process, detrainment, coherent entrainment structures, and mixing inside the ABL, are presented. Thermals overshooting at the ABL top are shown to create disturbances in the form of gravity waves in the free atmosphere aloft, as evidenced by a corresponding ripple structure at the bottom of the smoke layer. Lidar data, aerosol ground-based measurements and supporting meteorological data are used to link free atmosphere, mixed-layer and ground-level aerosols. During the peak period of the haze event (July 7, 2002), the correlation between time series of elastic backscatter lidar data within the mixed layer and the scattering coefficient from a nephelometer at ground level was found to be high (R=0.96 for z =324 m, and R=0.89 for z=504 m). Ground-level aerosol concentration was at a maximum about 2 h after the smoke layer intersected with the growing ABL, confirming that the wisps do not initially reach the ground.
Similar content being viewed by others
References
J. D. Albertson M. B. Parlange (1999) ArticleTitle‘Surface Length Scales and Shear Stress: Implications for Land-Atmosphere Interaction over Complex Terrain’ Water Resour. Res 35 2121–2132
W. M. Angevine A. W. Grimsdell L. M. Hartten A. C. Delany (1998a) ArticleTitle‘The Flatland Boundary Layer Experiment’ Bull. Amer. Meteorol. Soc 79 419–431
W. M. Angevine A. W. Grimsdell S. A. McKeen J. M. Warnock (1998b) ArticleTitle‘Entrainment Results from the Flatland Boundary Layer Experiments’ J. Geophys. Res. 103 13689–13701
J. W. Deardorff G. E. Willis (1982) ArticleTitle‘Ground-level Concentrations Due to Fumigation into an Entraining Mixed Layer’ Atmos. Environ 16 1159–1170
J. W. Deardorff G. E. Willis D. K. Lilly (1969) ArticleTitle‘Laboratory Investigation of Nonsteady Penetrative Convection’ J. Fluid Mech 35 7–31
J. W. Deardorff G. E. Willis B. H. Stockton (1980) ArticleTitle‘Laboratory Studies of the Entrainment Zone of a Convectively Mixed Layer’ J. Fluid Mech 100 41–64
A. G. M. Driedonks P. G. Duynkerke (1989) ArticleTitle‘Current Problems in the Stratocumulus-topped Atmospheric Boundary Layer’ Boundary-Layer Meteorol 46 275–303
E. Fedorovich J. Thäter (2002) ArticleTitle‘A Wind Tunnel Study of Gaseous Tracer Dispersion in the Convective Boundary Layer Capped by a Temperature Inversion’ Atmos. Environ 36 2245–2255
H. J. S. Fernando S. M. Lee J Anderson M. Princevac E. Pardyjak S. Grossmann-Clarke (2001) ArticleTitle‘Urban Fluid Mechanics: Air Circulation and Contaminant Dispersion in Cities’ Environ. Fluid Mech 1 107–164
G. J. Fochesatto P. Drobinski C. Flamant D. Guedalia C. Sarrat P. H. Flamant J. Pelon (2001) ArticleTitle‘Evidence of Dynamic Coupling between the Residual Layer and the Developing Convective Boundary Layer’ Boundary-Layer Meteorol 99 451–464
C. Forster U. Wandinger G. Wotawa P. James I. Mattis D. Althausen P. Simmonds S. O’Doherty S. G. Jennings C. Kleefeld J. Schneider T. Trickl S. Kreipl H. Jager A. Stohl (2001) ArticleTitle‘Transport of Boreal Forest Fire Emissions from Canada to Europe’ J. Geophys. Res 106 22887–22906
J. R. Garratt (1992) The Atmospheric Boundary Layer Cambridge University Press Cambridge, U.K. 316
E. Gossard J. H. Richter (1970) ArticleTitle‘The Shape of Internal Waves of Finite Amplitude from High Resolution Radar Sounding of the Lower Atmosphere’ J. Atmos. Sci 27 971–973
Iziomon, M. G. and Lohmann, U.: 2003, ‘Optical and Meteorological Properties of Smoke-dominated Haze at the ARM Southern Great Plains Central Facility’, Geophys. Res. Lett. 30, doi:10.1029/2002GL016606
S. Menon J. Hansen L. Nazarenko Y. Luo (2002) ArticleTitle‘Climate Effects of Black Carbon Aerosols in China and India’ Science 297 2250–2253
L. Menut C. Flamant J. Pelon P. H. Flamant (1999) ArticleTitle‘Urban Boundary-Layer Height Determination from Lidar Measurements over the Paris Area’ Appl. Opt 38 945–954
J. I. Metcalf (1975) ArticleTitle‘Gravity Waves in a Low Level Inversion’ J. Atmos. Sci 32 351–361
C.-H. Moeng (1998) ‘Stratocumulus-Topped Atmospheric Planetary Boundary Layer’ E. J. Plate (Eds) et al. Buoyant Convection in Geophysical Flows, NATO Science Series C, Vol. 513 Kluwer Academic Publishers Dordrecht 421–440
C.-H. Moeng P. P. Sullivan B. Stevens (1999) ArticleTitle‘Including Radiative Effects in an Entrainment Rate Formula for Buoyancy-Driven PBLs’ J. Atmos. Sci 56 1031–1049
P. Monti H. J. S. Fernando M. Princevac W. C. Chan T. A. Kowalewski E. R. Pardyjak (2002) ArticleTitle‘Observations of Flow and Turbulence in the Nocturnal Boundary Layer over a Slope’ J. Atmos. Sci 59 2513–2534
Pahlow, M.: 2002, Atmospheric Boundary-Layer Dynamics and Inversion Technologies to Obtain Extinction Coefficient Profiles in the Atmosphere from Elastic Lidar, Ph.D. Dissertation, Johns Hopkins University, Baltimore, MD, U.S.A., 209 pp.
A. Robock (1988a) ArticleTitle‘Enhancement of Surface Cooling Due to Forest Fire Smoke’ Science 242 911–913
A. Robock (1988b) ‘Surface Temperature Effects of Forest Fire Smoke Plumes’ P. V. Hobbs M. P. McCormick (Eds) Aerosols and Climate Deepak Publishing Hampton, VA 435–442
R. S. Scorer (1957) ArticleTitle‘Experiment on Convection of Isolated Masses of Buoyant Fluid’ J. Fluid Mech 2 583–594
J. M. Sigler X. Lee W. Munger (2003) ArticleTitle‘Emission and Long-Range Transport of Gaseous Mercury from a Large-Scale Canadian Boreal Forest Fire’ Environ. Sci. Technol 37 4343–4347
W. R. Skinner M. D. Flannigan B. J. Stocks D. L. Martell B. M. Wotton J. B. Todd J. A. Mason K. A. Logan E. M. Bosch (2002) ArticleTitle‘A 500 hPa Synoptic Wildland Fire Climatology for Large Canadian Forest Fires, 1959–1996’ Theor. Appl. Climatol 71 157–169
W. R. Skinner B. J. Stocks D. L. Martell B. Bonsal A. Shabbar (1999) ArticleTitle‘The Association between Circulation Anomalies in the Mid-Troposphere and Area Burned by Wildland Fire in Canada’ Theor. Appl. Climatol 63 89–105
A. Slingo S. Nicholls J. Schmertz (1982) ArticleTitle‘Aircraft Observations of Marine Stratocumulus during JASIN’ Quart. J. Roy. Meteorol. Soc 108 833–856
R. B. Stull (1976a) ArticleTitle‘The Energetics of Entrainment across a Density Interface’ J. Atmos. Sci. 33 1260–1267
R. B. Stull (1976b) ArticleTitle‘Internal Gravity Waves Generated by Penetrative Convection’ J. Atmos. Sci. 33 1279–1286
R. B. Stull (1988) An Introduction to Boundary Layer Meteorology Kluwer Adademic Publishers Dordrecht 666
P. P. Sullivan C.-H. Moeng B. Stevens D. H. Lenshow S. D. Mayor (1998) ArticleTitle‘Structure of the Entrainment Zone Capping the Convective Atmospheric Boundary Layer’ J. Atmos. Sci 55 3042–3064
M. G. Weber B. J. Stocks (1998) ArticleTitle‘Forest Fires and Sustainability in the Boreal Forests of Canada’ Ambio 27 545–550
G. Wotawa M. Trainer (2000) ArticleTitle‘The Influence of Canadian forest Fires on Pollutant Concentrations in the United States’ Science 288 324–328
J. C. Wyngaard R. A. Brost (1984) ArticleTitle‘Top-Down and Bottom-Up Diffusion of a Scalar in the Convective Boundary Layer’ J. Atmos. Sci 41 102–112
C. Yi K. J. Davis B. W. Berger P. S. Bakwin (2001) ArticleTitle‘Long-Term Observations of the Dynamics of the Continental Planetary Boundary Layer’ J. Atmos. Sci 58 1288–1299
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pahlow, M., Kleissl, J. & Parlange, M.B. Atmospheric boundary-layer structure observed during a haze event due to forest-fire smoke. Boundary-Layer Meteorol 114, 53–70 (2005). https://doi.org/10.1007/s10546-004-6350-z
Received:
Issue Date:
DOI: https://doi.org/10.1007/s10546-004-6350-z