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Stephan Franz Joseph De Wekker

Stephan Franz Joseph De Wekker

Professor, Environmental Sciences

Primary Location
PO Box 400123 Department of Environmental Sciences
380A New Clark Hall
Primary Phone Number
Fax Number
434.982.2137

Bio & Overview

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.

Academic Information

Department
Environmental Sciences

Research Interests

Boundary-layer meteorology, mountain meteorology, mesoscale modeling, land-atmosphere interactions

Research Disciplines

  • Environmental Sciences

Selected Publications

2024

Duine, G. -J., De Wekker, S. F. J., & Knievel, J. C. (2024). The Influence of Terrain Smoothing on Simulated Convective Boundary-Layer Depths in Mountainous Terrain. ATMOSPHERE, 15(2). doi:10.3390/atmos15020145

2020

Crowe, D., Pamula, R., Cheung, H. Y., & De Wekker, S. E. J. (2020). Two Supervised Machine Learning Approaches for Wind Velocity Estimation Using Multi-Rotor Copter Attitude Measurements. SENSORS, 20(19). doi:10.3390/s20195638

Gonzalez-Rocha, J., De Wekker, S. F. J., Ross, S. D., & Woolsey, C. A. (2020). Wind Profiling in the Lower Atmosphere from Wind-Induced Perturbations to Multirotor UAS. SENSORS, 20(5). doi:10.3390/s20051341

2019

Palomaki, R. T., Babic, N., Duine, G. -J., van den Bossche, M., & De Wekker, S. F. J. (2019). Observations of Thermally-Driven Winds in a Small Valley during the 21 August 2017 Solar Eclipse. ATMOSPHERE, 10(7). doi:10.3390/atmos10070389

Babic, N., & De Wekker, S. F. J. (2019). Characteristics of roll and cellular convection in a deep and wide semiarid valley: A large-eddy simulation study. ATMOSPHERIC RESEARCH, 223, 74-87. doi:10.1016/j.atmosres.2019.03.009

2018

Grant, E. H. C., Brand, A. B., De Wekker, S. F. J., Lee, T. R., & Wofford, J. E. B. (2018). Evidence that climate sets the lower elevation range limit in a high-elevation endemic salamander. ECOLOGY AND EVOLUTION, 8(15), 7553-7562. doi:10.1002/ece3.4198

van den Bossche, M., & De Wekker, S. F. J. (2019). Representativeness of wind measurements in moderately complex terrain. THEORETICAL AND APPLIED CLIMATOLOGY, 135(1-2), 491-504. doi:10.1007/s00704-018-2402-z

De Wekker, S. F. J., Kossmann, M., Knievel, J. C., Giovannini, L., Gutmann, E. D., & Zardi, D. (2018). Meteorological Applications Benefiting from an Improved Understanding of Atmospheric Exchange Processes over Mountains. ATMOSPHERE, 9(10). doi:10.3390/atmos9100371

Lee, T. R., De Wekker, S. F. J., & Pal, S. (2018). The Impact of the Afternoon Planetary Boundary-Layer Height on the Diurnal Cycle of CO and Mixing Ratios at a Low-Altitude Mountaintop. BOUNDARY-LAYER METEOROLOGY, 168(1), 81-102. doi:10.1007/s10546-018-0343-9

Serafin, S., Adler, B., Cuxart, J., De Wekker, S. F. J., Gohm, A., Grisogono, B., . . . Zardi, D. (2018). Exchange Processes in the Atmospheric Boundary Layer Over Mountainous Terrain. ATMOSPHERE, 9(3). doi:10.3390/atmos9030102

2017

Duine, G. -J., & De Wekker, S. F. J. (2020). The effects of horizontal grid spacing on simulated daytime boundary layer depths in an area of complex terrain in Utah. ENVIRONMENTAL FLUID MECHANICS, 20(5), 1313-1331. doi:10.1007/s10652-017-9547-7

Palomaki, R. T., Rose, N. T., van den Bossche, M., Sherman, T. J., & De Wekker, S. F. J. (2017). Wind Estimation in the Lower Atmosphere Using Multirotor Aircraft. JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 34(5), 1183-1191. doi:10.1175/JTECH-D-16-0177.1

van den Bossche, M., Rose, N. T., & De Wekker, S. F. J. (2017). Potential of a low-cost gas sensor for atmospheric methane monitoring. SENSORS AND ACTUATORS B-CHEMICAL, 238, 501-509. doi:10.1016/j.snb.2016.07.092

Pal, S., Lee, T. R., & De Wekker, S. F. J. (2017). A study of the combined impact of boundary layer height and near surface meteorology on the CO diurnal cycle at a low mountaintop site using simultaneous lidar and in-situ observations. ATMOSPHERIC ENVIRONMENT, 164, 165-179. doi:10.1016/j.atmosenv.2017.05.041

Babic, N., Vecenaj, Z., & De Wekker, S. F. J. (2017). Spectral gap characteristics in a daytime valley boundary layer. QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 143(707), 2509-2523. doi:10.1002/qj.3103

2016

Lee, T. R., & De Wekker, S. F. J. (2016). Estimating Daytime Planetary Boundary Layer Heights over a Valley from Rawinsonde Observations at a Nearby Airport: An Application to the Page Valley in Virginia, United States. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 55(3), 791-809. doi:10.1175/JAMC-D-15-0300.1

Gultepe, I., Fernando, H. J. S., Pardyjak, E. R., Hoch, S. W., Silver, Z., Creegan, E., . . . Hang, C. (2016). An Overview of the MATERHORN Fog Project: Observations and Predictability. PURE AND APPLIED GEOPHYSICS, 173(9), 2983-3010. doi:10.1007/s00024-016-1374-0

Pal, S., De Wekker, S. F. J., & Emmitt, G. D. (2016). Investigation of the Spatial Variability of the Convective Boundary Layer Heights over an Isolated Mountain: Cases from the MATERHORN-2012 Experiment. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 55(9), 1927-1952. doi:10.1175/JAMC-D-15-0277.1

van den Bossche, M., & De Wekker, S. F. J. (2016). Spatiotemporal Variability of Surface Meteorological Variables During Fog and No-Fog Events in the Heber Valley, UT; Selected Case Studies From MATERHORN-Fog. PURE AND APPLIED GEOPHYSICS, 173(9), 3031-3048. doi:10.1007/s00024-016-1352-6

2015

Babic, N., Vecenaj, Z., & De Wekker, S. F. J. (2016). Flux-Variance Similarity in Complex Terrain and Its Sensitivity to Different Methods of Treating Non-stationarity. BOUNDARY-LAYER METEOROLOGY, 159(1), 123-145. doi:10.1007/s10546-015-0110-0

Babic, N., Vecenaj, Z., Kozmar, H., Horvath, K., De Wekker, S. F. J., & Grisogono, B. (2016). On Turbulent Fluxes During Strong Winter Bora Wind Events. BOUNDARY-LAYER METEOROLOGY, 158(2), 331-350. doi:10.1007/s10546-015-0088-7

Serafin, S., De Wekker, S. F. J., & Knievel, J. C. (2016). A Mesoscale Model-Based Climatography of Nocturnal Boundary-Layer Characteristics over the Complex Terrain of North-Western Utah. BOUNDARY-LAYER METEOROLOGY, 159(3), 495-519. doi:10.1007/s10546-015-0044-6

He, Y., D'Odorico, P., & De Wekker, S. F. J. (2015). The role of vegetation-microclimate feedback in promoting shrub encroachment in the northern Chihuahuan desert. GLOBAL CHANGE BIOLOGY, 21(6), 2141-2154. doi:10.1111/gcb.12856

Lee, T. R., De Wekker, S. F. J., Pal, S., Andrews, A. E., & Kofler, J. (2015). Meteorological controls on the diurnal variability of carbon monoxide mixing ratio at a mountaintop monitoring site in the Appalachian Mountains. TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY, 67. doi:10.3402/tellusb.v67.25659

De Wekker, S. F. J., & Kossmann, M. (2015). Convective Boundary Layer Heights Over Mountainous Terrain A Review of Concepts. FRONTIERS IN EARTH SCIENCE, 3. doi:10.3389/feart.2015.00077

Fernando, H. J. S., Pardyjak, E. R., Di Sabatino, S., Chow, F. K., De Wekker, S. F. J., Hoch, S. W., . . . Zsedrovits, T. (2015). THE MATERHORN Unraveling the Intricacies of Mountain Weather. BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY, 96(11). doi:10.1175/BAMS-D-13-00131.1

2014

Vecenaj, Z., & De Wekker, S. F. J. (2015). Determination of non-stationarity in the surface layer during the T-REX experiment. QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 141(690), 1560-1571. doi:10.1002/qj.2458

Pal, S., Lee, T. R., Phelps, S., & De Wekker, S. F. J. (2014). Impact of atmospheric boundary layer depth variability and wind reversal on the diurnal variability of aerosol concentration at a valley site. SCIENCE OF THE TOTAL ENVIRONMENT, 496, 424-434. doi:10.1016/j.scitotenv.2014.07.067

He, Y., D'Odorico, P., & De Wekker, S. F. J. (2015). The relative importance of climate change and shrub encroachment on nocturnal warming in the southwestern United States. INTERNATIONAL JOURNAL OF CLIMATOLOGY, 35(3), 475-480. doi:10.1002/joc.3992

Lee, T. R., De Wekker, S. F. J., & Wofford, J. E. B. (2014). Downscaling Maximum Temperatures to Subkilometer Resolutions in the Shenandoah National Park of Virginia, USA. ADVANCES IN METEOROLOGY, 2014. doi:10.1155/2014/594965

Andrews, A. E., Kofler, J. D., Trudeau, M. E., Williams, J. C., Neff, D. H., Masarie, K. A., . . . Tans, P. P. (2014). CO2, CO, and CH4 measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network: instrumentation, uncertainty analysis, and recommendations for future high-accuracy greenhouse gas monitoring efforts. ATMOSPHERIC MEASUREMENT TECHNIQUES, 7(2), 647-687. doi:10.5194/amt-7-647-2014

2013

Andrews, A. E., Kofler, J. D., Trudeau, M. E., Williams, J. C., Neff, D. H., Masarie, K. A., . . . Tans, P. P. (2013). CO<sub>2</sub>, CO and CH<sub>4</sub> measurements from the NOAA Earth System Research Laboratory's Tall Tower Greenhouse Gas Observing Network: instrumentation, uncertainty analysis and recommendations for future high-accuracy greenhouse gas monitoring efforts. doi:10.5194/amtd-6-1461-2013

2012

D'Odorico, P., He, Y., Collins, S., De Wekker, S. F. J., Engel, V., & Fuentes, J. D. (2013). Vegetation-microclimate feedbacks in woodland-grassland ecotones. GLOBAL ECOLOGY AND BIOGEOGRAPHY, 22(4), 364-379. doi:10.1111/geb.12000

Godwin, K. S., De Wekker, S. F. J., & Emmitt, G. D. (2012). Retrieving Winds in the Surface Layer over Land Using an Airborne Doppler Lidar. JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, 29(4), 487-499. doi:10.1175/JTECH-D-11-00139.1

De Wekker, S. F. J., Godwin, K. S., Emmitt, G. D., & Greco, S. (2012). Airborne Doppler Lidar Measurements of Valley Flows in Complex Coastal Terrain. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 51(8), 1558-1574. doi:10.1175/JAMC-D-10-05034.1

Lee, T. R., De Wekker, S. F. J., Andrews, A. E., Kofler, J., & Williams, J. (2012). Carbon dioxide variability during cold front passages and fair weather days at a forested mountaintop site. ATMOSPHERIC ENVIRONMENT, 46, 405-416. doi:10.1016/j.atmosenv.2011.09.068

2011

He, Y., De Wekker, S. F. J., Fuentes, J. D., & D'Odorico, P. (2011). Coupled land-atmosphere modeling of the effects of shrub encroachment on nighttime temperatures. AGRICULTURAL AND FOREST METEOROLOGY, 151(12), 1690-1697. doi:10.1016/j.agrformet.2011.07.005

Desai, A. R., Moore, D. J. P., Ahue, W. K. M., Wilkes, P. T. V., De Wekker, S. F. J., Brooks, B. G., . . . Schimel, D. S. (2011). Seasonal pattern of regional carbon balance in the central Rocky Mountains from surface and airborne measurements. JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES, 116. doi:10.1029/2011JG001655

Schmidli, J., Billings, B., Chow, F. K., de Wekker, S. F. J., Doyle, J., Grubisic, V., . . . Zaengl, G. (2011). Intercomparison of Mesoscale Model Simulations of the Daytime Valley Wind System. MONTHLY WEATHER REVIEW, 139(5), 1389-1409. doi:10.1175/2010MWR3523.1

Vecenaj, Z., De Wekker, S. F. J., & Grubisic, V. (2011). Near-Surface Characteristics of the Turbulence Structure during a Mountain-Wave Event. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 50(5), 1088-1106. doi:10.1175/2010JAMC2450.1

2010

He, Y., D'Odorico, P., De Wekker, S. F. J., Fuentes, J. D., & Litvak, M. (2010). On the impact of shrub encroachment on microclimate conditions in the northern Chihuahuan desert. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 115. doi:10.1029/2009JD013529

Sun, J., Oncley, S. P., Burns, S. P., Stephens, B. B., Lenschow, D. H., Campos, T., . . . Coons, T. (2010). A MULTISCALE AND MULTIDISCIPLINARY INVESTIGATION OF ECOSYSTEM-ATMOSPHERE CO2 EXCHANGE OVER THE ROCKY MOUNTAINS OF COLORADO. BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY, 91(2), 209-230. doi:10.1175/2009BAMS2733.1