Atmospheric Science

College of Engineering and Physical Sciences

Bart Geerts,

Professor

Room 6065,  Engineering Building
email: geerts@uwyo.edu
Office Phone: (307) 766-2261
Visit Dr. Geerts' personal website

Education:

  • B.A., Physical Geography, University of Louvain in Belgium, 1984

  • M.S., Irrigation Engineering, University of Louvain in Belgium, 1985

  • Ph.D., Atmospheric Science, University of Washington, 1990

Bart Geerts mugshot, Sept 2022

Research Statement

Bart Geerts and his graduate students conduct research into cloud-scale to mesoscale atmospheric processes, mainly using aircraft measurements and a variety of radars, especially the vertically profiling airborne Wyoming Cloud Radar. A related and more recent research topic regards regional climate modeling, focused mainly on orographic precipitation in the Interior Western US. This work is part of the WyACT project.

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Current Projects/Research Areas

Regional climate modeling of orographic precipitation in the Intramountain Western US.

Boundary-layer circulations over relatively warm water. We examined during cold-air outbreaks over Lake Michigan, using the UW King Air and WCR in a NASA-funded project in early 2004. BL circulations over warm water and downstream land areas were further examined in OWLES, an NSF-funded project conducted over Lake Ontario in Dec 2013 - Jan 2014. We also led COMBLE (Cold air Outbreaks over the Marine Boundary Layer Experiment), which deployed the first DOE ARM Mobile Facility on the coast of northern Norway, for 6 months started in Dec '19. Our latest effort is the CAESAR project, which aims to fly the NSF/NCAR C-130 aircraft with Wyoming radars and lidars over BL convection over the open water in the far northern North Atlantic, near the ice edge. The CAESAR campaign is targeted for early 2024.

Dynamics and microphysics of orographic precipitation. We have been taking the UW King Air with radar and lidar over Wyoming mountain ranges since 2006, to study natural orographic precipitation processes and snowfall enhancement by means of glaciogenic seeding of orographic clouds. The first NSF-funded project was ASCII, conducted in 2012-13 over the Sierra Madre and Medicine Bow Ranges, where we deployed a dual-pol DOW radar at 10,000 ft above sea level. A more intensive follow-up campaign is SNOWIE, conducted in early 2017 in Idaho.

Dynamics of radar fine-lines in the pre-convective continental boundary layer . We used data collected in IHOP (International Water Vapor Experiment, May-June 2002, funded by NSF), in particular the UW King Air and WCR data, to examine a vertical velocity bias found in radar data of the optically-clear convective boundary-layer, the dynamics of coherent eddies in the convective boundary-layer, the fine-scale structure of boundaries such as cold fronts and drylines, and convective initiation mechanisms. A large follow-up campaign, PECAN (June-July 2015), focused on organized convection at night, in the presence of a stable boundary layer and a LLJ. In PECAN we study the evolution of outflow boundaries, including bores and solitary waves, and their potential to trigger new convection.

Dynamical and microphysical processes in cumuli (since 2006). Data collected in CuPIDO (also funded by NSF) were used to study the dynamics of towering cumuli over the Santa Catalina Mountains in Arizona in summer, Cu detrainment, and the interaction of cumulus convection with the topographically-controlled mesoscale circulation. Again we used the UW King Air with WCR, plus soundings, surface stations, digital photogrammetry, profiling remote sensors, and numerical modeling.

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Publications

Google Scholar Webpage

Orcid Webpage

Select Publications

  • Geerts, B., G.M. Heymsfield, L. Tian, J.B. Halverson, A. Guillory, and M.I. Mejia, 2000: Hurricane Georges' landfall in the Dominican Republic: detailed airborne Doppler radar imagery. Bull. Amer. Meteor. Soc., 81, 999-1018.

  • Weckwerth, Parsons, Koch, Moore, LeMone, Demoz, Flamant, Geerts, Wang, and Feltz, 2004: An overview of the International H2O Project (IHOP_2002) and some preliminary highlights. Bull. Amer. Meteor. Soc., 85, 253-277.

  • Geerts, B. and Q. Miao, 2005: The use of millimeter Doppler radar echoes to estimate vertical air velocities in the fair-weather convective boundary layer. J. Atmos. Ocean. Tech. , 22, 225-246. [highlighted as a “Paper of Note” in the Oct 2005 issue of the Bull. Amer. Meteor. Soc., with Fig. 1 used as Fig. 4.1 in the textbook Markowski and Richardson (2010)]

  • Geerts, B., S. Koch, P. Krehbiel, and D. Jorgensen, 2006: Changing Conference Practices: A Report from the 32nd Radar Meteorology and 11th Mesoscale Processes Joint Conference. Bull. Amer. Meteor. Soc., 87, 1105-1110.

  • Geerts, B., R. Damiani, and S. Haimov, 2006: Fine-scale vertical structure of a cold front as revealed by airborne radar. Mon. Wea. Rev., 134, 251–272

  • Geerts, B., Q. Miao, and J.C. Demko, 2008: Pressure perturbations and upslope flow over a heated, isolated mountain. Mon. Wea. Rev., 136, 4272–4288.

  • Geerts, B., Q. Miao, Y. Yang, R. Rasmussen, and D. Breed, 2010: An airborne profiling radar study of the impact of glaciogenic cloud seeding on snowfall from winter orographic clouds. J. Atmos. Sci., 67, 3286–3302.

  • Geerts, B., Q. Miao, and Y. Yang, 2011: Boundary-layer turbulence and orographic precipitation growth in cold clouds: evidence from profiling airborne radar data. J. Atmos. Sci., 68, 2344-2365.

  • Geerts, B., Y. Yang, R. Rasmussen, S. Haimov, and B. Pokharel, 2015: Snow growth and transport patterns in orographic storms as estimated from airborne vertical-plane dual-Doppler radar data. Mon. Wea. Rev. , 143, 644-665.

  • Geerts, B., B. Pokharel, and D. Kristovich, 2015: Blowing snow as a natural glaciogenic cloud seeding mechanism. Mon. Wea. Rev., 143, 5017–5033

  • Pokharel, B., B. Geerts, X. Jing, K. Friedrich, K. Ikeda, and R. Rasmussen, 2016: A multi-sensor study of the impact of ground-based glaciogenic seeding on clouds and precipitation over mountains in Wyoming. Part II: Seeding impact analysis. Atmos. Res., 183, 42–57.

  • Geerts, B., and Co-authors, 2017: The 2015 Plains Elevated Convection At Night (PECAN) field project. Bull. Amer. Meteor. Soc., 98, 767-786. (http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-15-00257.1)

  • Kristovich, D., and Co-authors, 2017: The Ontario Winter Lake-effect Systems (OWLeS) field campaign: scientific and educational adventures to further our knowledge and prediction of lake-effect storms. Bull. Amer. Meteor. Soc., 98, 315-332. (http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-15-00034.1)

 
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