Faculty & Staff

Faculty

Stephan De Wekker

Assistant Professor · Ph.D. University of British Columbia, 2002

Contact Information

Landscape heterogeneities can have pronounced effects on atmospheric boundary layer processes. Examples include a modification of the boundary layer growth and the generation of mesoscale circulations. My research focuses primarily on the investigation of these processes in hilly and mountainous terrain using a combination of field studies, data analysis, and numerical modeling techniques. I seek to apply my expertise to problems in a multi-disciplinary context such as found at the interface with ecology, atmospheric chemistry, and hydrology. Examples include the venting and regional transport of aerosols and the estimation of regional CO2 fluxes.

Recent Publications

Večenaj, Z., S.F.J. De Wekker, and V. Grubišić, 2011: Near Surface Characteristics of the Turbulence Structure During a Mountain Wave Event. Accepted for publication in Journal of Applied Meteorology and Climatology, December 2010

Schmidli, J., B. Billings, F.K. Chow, S.F.J. De Wekker, J. Doyle, V. Grubisic, T. Holt, Q. Jiang, K. A. Lundquist, P. Sheridan, S. Vosper, C. D. Whiteman, A. Wyszogrodzki, G. Zangl, 2011: Intercomparison of mesoscale model simulations of the daytime valley wind system. Accepted for publication in Monthly Weather Review, October 2010

D’Odorico, P., J.D. Fuentes, W.T. Pockman, S.L. Collins, Y. He, J.A. Medeiros, S.F.J. De Wekker, and M.E. Litvak, 2010: Positive feedback between microclimate and shrub encroachment in the northern Chihuahuan desert. Ecosphere 1(6):art17. doi:10.1890/ES10-00073.1

He, Y., P. D'Odorico, S.F.J. De Wekker, J. D. Fuentes, and M. Litvak, 2010: On the impact of shrub encroachment on microclimate conditions in the northern Chihuahuan desert, J. Geophys. Res., 115, D21120, doi:10.1029/2009JD013529.

Sun, J., S.P. Oncley, S.P. Burns, B.B. Stephens, D.H. Lenschow, T. Campos, R.K. Monson, D.S. Schimel, W.J. Sacks, S.F.J. De Wekker, C. Lai, B. Lamb, D. Ojima, P.Z. Ellsworth, L.S.L. Sternberg, S. Zhong, C. Clements, D.J.P. Moore, D.E. Anderson, A.S. Watt, J. Hu, M. Tschudi, S. Aulenbach, E. Allwine, T. Coons, 2009: A Multi-scale and Multi-disciplinary Investigation of Ecosystem-Atmosphere CO2 Exchange over the Rocky Mountains of Colorado. Bull. Amer. Meteor. Soc., 91, 209–230.

De Wekker, S.F.J. A. Ameen, G. Song, B.B. Stephens, A.G. Hallar, and I. McCubbin, 2009: A preliminary investigation of boundary layer effects on daytime atmospheric CO2 concentrations at a mountaintop location in the Rocky Mountains. Acta Geophysica 57, 904-922.

De Wekker, S.F.J. and S. D. Mayor, 2009: Observations of atmospheric structure and dynamics in the Owens Valley of California with a ground-based, eye-safe, scanning aerosol lidar. J. Appl Meteor. Climat. 48, 1483–1499.

Doyle, J.D., V. Grubišić, W,O.J. Brown, S.F.J. De Wekker, A. Dörnbrack, Q. Jiang, S.D. Mayor, M. Weissmann, 2009: Observations and numerical simulations of subrotor vortices during T-REX. J. Atmos. Sci., 66, 1229-1249.

Grubišić, V., J.D. Doyle, J. Kuettner, S. Mobbs, R.B. Smith, C.D. Whiteman, R. Dirks, S. Czyzyk, S.A. Cohn, S. Vosper, M. Weissmann, S. Haimov, S.F.J. De Wekker, L.L. Pan, and F.K. Chow, 2008: The Terrain-Induced Rotor Experiment. Bull. Amer. Meteor. Soc., 89, 1513–1533.

De Wekker, S.F.J., 2008: Observational and numerical evidence of depressed convective boundary layer heights near a mountain base. J. Appl Meteor. Climat. 47, 1017–1026.

Zhong, S., J. Li, C. B. Clements, S.F.J. De Wekker, and X. Bian, 2008: Forcing mechanisms for Washoe Zephyr - a daytime downslope wind system in the lee of the Sierra Nevada. J. Appl Meteor. Climat. 47, 339-350.

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. Climat., 46, 3–13.

De Wekker, S.F.J. and C.D. Whiteman, 2006: On the timescale of nocturnal boundary layer cooling in valleys, basins, and over plains. J. Appl. Meteor. Climat., 45, 813

De Wekker, S.F.J., D.G. Steyn, J.D. Fast, M.W. Rotach, and S. Zhong, 2005: The performance of RAMS in representing the convective boundary layer structure in a very steep valley. Env. Fluid Mech. 5, 35-62.

De Wekker, S.F.J., D.G. Steyn, and S. Nyeki, 2004: A comparison of aerosol layer and convective boundary layer structure over a mountain range during 97. Bound.-Layer Meteor. 113, 249-271.

Rotach, M.W, P. Calanca, R. Vogt, D.G. Steyn, G. Graziani, M. Andretta, A.Christen, S. Cieslik, R. Conolly, S.F.J. De Wekker, S. Galmarini, E. van Gorsel, J. Gurtz, E. Kadygrov, V. Kadygrov, E. Miller, B. Neininger, M. Rucker, H. Weber, A. Weiss , M. Zappa, 2004: The turbulence structure and exchange processes in an Alpine Valley: The MAP-Riviera project. Bull. Amer. Meteor. Soc. 85, 1367-1385.

Henne, S., M. Furger, S. Nyeki, M. Steinbacher, B. Neininger, S.F.J. De Wekker, J. Dommen, N. Spichtinger, A. Stohl, A. S. H. Prevot, 2004: Quantification of topographic venting of boundary layer air to the free troposphere. Atmos. Chem. Phys., 4, 497-509.

Nyeki, S., M. Kalberer, I. Colbeck, S.F.J. De Wekker, M. Furger, H.W. Gaeggeler, M. Kossmann, M. Lugauer, D. Steyn, E. Weingartner, M. Wirth, and U. Baltensperger, 2000: Convective Boundary Layer Evolution to 4 km asl over High-Alpine Terrain: Airborne Lidar observations in the Alps. Geophys. Res. Lett., 27, 689-692.

Nyeki, S., S.F.J. De Wekker, D. Steyn, M. Kossmann, M. Kalberer, I. Colbeck and U. Baltensperger, 1999: Airborne lidar study of convective boundary layer development over pre-alpine terrain, J. of Aerosol Science, 30, 209-210.

Kossmann, M., U. Corsmeier, S.F.J. De Wekker, F. Fiedler, R. Voegtlin, N. Kalthoff, H. Guesten, and B. Neininger, 1999. Observations of handover processes between the atmospheric boundary layer and the free troposphere over mountainous terrain. Contrib. Atmos. Phys., 72, 329-350.

De Wekker, S.F.J., S. Zhong, J.D. Fast, and C.D. Whiteman, 1998: A numerical study of the thermally driven plain-to-basin wind over idealized basin topographies. J. Appl. Meteor., 37, 606-622.

Doran, J.C., X. Bian, S.F.J. De Wekker, S. Edgerton, J.D. Fast, J.M. Hubbe, W.J. Shaw, C. D. Whiteman, S. Abbott, C. King, J. Leach, M. Mulhearn, C. Russell, B. Templeman, D. Wolfe, J. Archuleta, S. Elliott, A. Fernandez, D. Langley, J.T. Lee, W. Porch, L. Tellier, J. Chow, J.G. Watson, R.L. Coulter, T.J. Martin, J.D. Shannon, R. White, D. Martinez, J.L. Martinez, V. Mora, G. Sosa, G. Mercado, J.L. Pena, R. Salas, R. Petty, 1998: The IMADA-AVER Boundary Layer Experiment in the Mexico City Area. Bull. Amer. Meteor. Soc., 79, 2497.