College of Engineering and Physical Sciences

Gabor Vali, Professor Emeritus

Retired Since September 2006
Department of Atmospheric Science
College of Engineering and Physical Sciences
University of Wyoming
Mailing Address: 1000 E. University Ave., Laramie, WY 82071
E-mail: vali@uwyo.edu
Dept. phone: (307) 766-3245
Fax: (307) 766-2635

 

Education:

• B.S., Sir George Williams University (Montreal), 1961
• M.S., Physics, McGill University (Montreal), 1964
• Ph.D., Physics, McGill University (Montreal), 1968
  
  

Areas of Expertise:

• Cloud and precipitation physics. Ice nucleation.
  
  

Selected Publications (By Topic):

• Ice Nucleation

  • Vali, G. and R C Schnell, 2024: "Looking Back: An Account of How Ice Nucleation by Bacteria Was Discovered (1963 to about Mid-1980s). Part I: The Basics" Bull. Amer. Meteor. Soc. 105, E778- E788 https://doi.org/10.1175/BAMS-D-23-0114.1 

  • R. C. Schnell and G. Vali,, 2024: "Looking Back: An Account of How Ice Nucleation by Bacteria Was Discovered (1963 to about Mid-1980s). Part II: Broadening the Scope" Bull. Amer. Meteor. Soc. 105, E1014- E1024 https://doi.org/10.1175/BAMS-D-23-0115.1

  • Vali, G., 2023: "Comment on “A universally applicable method of calculating confidence bands for ice nucleation spectra derived from droplet freezing experiments” by Fahy et al. (2022)" Atmos. Meas. Tech., 16, 4303-4306. https://amt.copernicus.org/articles/16/4303/2023/

  • Vali, G., 2021: "Exploratory experiments on pre-activated freezing nucleation on mercuric iodide." Atmos. Chem. Phys., 21, 2551-2568. https://acp.copernicus.org/articles/21/2551/2021/

  • Vali, G., 2019: "Revisiting the differential freezing nucleus spectra derived from drop-freezing experiments: methods of calculation, applications, and confidence limits." Atmos. Meas. Tech., 12, 1219-1231.  https://amt.copernicus.org/articles/12/1219/2019/

  • "Novelties in ice nucleation terminology." Paper presented at the ICNAA conference in Helsinki. 2017.

  • Vali, G., P. J. DeMott, O. Möhler and T.F. Whale, 2015: "Technical Note: A proposal for ice nucleation terminology." Atmos. Chem. Phys., 15, 10263-10270. https://acp.copernicus.org/articles/15/10263/2015/

  • Vali, G. and J. R. Snider, 2015: "Time-dependent freezing rate parcel model" Atmos. Chem. Phys., 15, 2071-2079. https://acp.copernicus.org/articles/15/2071/2015/

  • Vali, G., 2014: "Interpretation of freezing nulceation experiments: singular and stochastic; sites and surfaces." Atmos. Chem. Phys., 14, 5271-5294. https://acp.copernicus.org/articles/14/5271/2014/

  • DeMott, Paul, J., Ottmar Möhler, Olaf Stetzer, Gabor Vali, Zev Levin, Markus D. Petters, Masataka Murakami, Thomas Leisner, Ulrich Bundke, Holger Klein, Zamin A. Kanji, Richard Cotton, Hazel Jones, Stefan Benz, Maren Brinkmann, Daniel Rzesanke, Harald Saathoff, Mathieu Nicolet, Atsushi Saito, Bjorn Nillius, Heinz Bingemer, Jonathan Abbatt, Karin Ardon, Eli Ganor, Dimitrios G. Georgakopoulos, Clive Saunders, 2011: Resurgence of ice nuclei measurement reserach. Bull. Amer. Meteor. Soc., 92, 1623-1635. https://journals.ametsoc.org/view/journals/bams/92/12/2011bams3119_1.xml

  • Vali, G., 2008: "Repeatability and randomness in heterogeneous freezing nucleation." Atmos. Chem. Phys., 8, 5017-5031. https://acp.copernicus.org/articles/8/5017/2008/

  • Möhler, O., P. J. DeMott, G. Vali, and Z. Levin, 2007: “Microbiology and atmospheric processes: the role of biological particles in cloud physics.” Biogeosciences, 4, 1059-1071. https://bg.copernicus.org/articles/4/1059/2007/bg-4-1059-2007.pdf

  • "Ice initiation in the atmosphere and in the laboratory."   September 26, 2007 talk given at the International Workshop on Comparing Ice Nucleation Measuring Systems, ICIS-07, Karlsruhe, Germany.

  • "Ice Observations, 1949-2004; Part 1 - Historical."  June 7, 2004 presentation at the Ice Initiation Workshop, Boulder, Colorado.

  • "Ice Observations, 1949-2004: Part 2a Wave Clouds and Part 2b Convective Clouds."  June 7, 2004 presentation at the Ice Initiation Workshop, Boulder, Colorado.

  • "Ice nucleation - theory. A tutorial." Presentation at the 1999 NCAR/ASP Summer Colloquium.

  • "Ice nucleation - a review." 1996 

  • "Jégkézödés a légkörben és a bioszferaban" Magyar Tudomány, 8, 922-934. 1995.

  • "Principles of ice nucleation." Chapter 1. in "Biological Ice Nucleation and Its Applications" R.E. Lee Jr. and G.J. Warren editors, APS Press, St.Paul, Minnesota. pp.1 - 28. 1995.

  • "The discovery of bacterial ice nucleation and the role of bacterial ice nucleation in frost injury to plants" by C.D. Upper and G. Vali. Chapter 2 in "Biological Ice Nucleation and Its Applications" R.E. Lee Jr. and G.J. Warren editors, APS Press, St.Paul, Minnesota. pp. 29-40. 1995.

  • "Freezing rate due to heterogeneous nucleation." J. Atmos. Sci., 51,1843-1856. 1994. https://doi.org/10.1175/1520-0469(1994)051<1843:FRDTHN>2.0.CO;2

  • "Memory effect in the nucleation of ice on mercuric iodide". in "Nucleation and Atmospheric Aerosols", N. Fukuta and P. Wagner (eds.), A. Deepak Publ., 1992.

  • "Atmospheric ice nucleation - a review" J. Rech. Atmos., 19, 105-112.1985. 

  • “Quantitative Evaluation of Experimental Results on the Heterogeneous Freezing Nucleation of Supercooled Liquids”, J. Atmos. Sci., 28, 402-409. https://doi.org/10.1175/1520-0469(1971)028<0402:QEOERA>2.0.CO;2

• Cloud Studies (In Situ and WCR radar)

  • "LIDAR and RADAR observations". 2013. Co-Editor with J. Pelon of Chapter 9 in Airborne Measurments for Environmental Research: Methods and Instruments.  Wiley Series in Atmospheric Physics and Remote Sensing. http://eu.wiley.com/WileyCDA/WileyTitle/productCd-3527409963.html

  • Wang, Z., J. French, G. Vali, P. Wechsler, S. Haimov, A. Rodi, M. Deng, D. Leon, J. Snider, L. Peng, and A. L. Pazmany, 2012:  "Single Aircraft Integration of Remote Sensing and In-situ Sampling for the Study of Cloud Microphysics and Dynamics."  Bull. Amer. Meteor. Soc., 93, 653-668. http://dx.doi.org/10.1175/BAMS-D-11-00044.1

  • Vali, G., D. Leon, and J. R. Snider, 2012: "Ground-layer snow clouds."  Quart. J. Roy. Meteor. Soc., 138, 1507-1525. http://dx.doi.org/10.1002/qj.1882

  • Pokharel, B. and G. Vali, 2011: "Evaluation of co-located measurements of radar reflectivity and particle sizes in cie clouds"   J. Appl. Meteor. Climat., 50, 2104-2119, doi: 2110.1175/JAMC-D-2110-05010.05011.http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-10-05010.1

  • “Clouds and precipitation” – talk given at an Advanced Studies Program of NCAR, 2009. 

  • Vali, G., B. Geerts, D. Leon and J.R. Snider, 2008: "Surface sources of ice particles in mountain clouds."  Paper presented at the 15th International Conference on Clouds and Precipitation. Cancun, Mexico. July 2008.

  • Damiani, R. and G. Vali, 2007: "Evidence for tilted toroidal circulation in cumulus." J. Atmos. Sci., 64, 2045-2060. https://journals.ametsoc.org/view/journals/atsc/64/6/jas3941.1.xml?rskey=fxFmXG&result=1

  • "Cloud structure influence on ice formation. Looking deep into clouds with an airborne radar. " October 22, 2007 talk given at the 9th WMO Scientific Conference on Weather Modification. Antalya, Turkey.

  • "Summary of IAPSAG findings." Talk given as part of the Forum of the 9th WMO Scientific Conference on Weather Modification, October 25, 2007.

  • Petters, M. D., J. R. Snider, B. Stevens, et al., 2006: “Accumulation mode aerosol, pockets of open cells, and particle nucleation in the remote subtropical pacific marine boundary layer.”  J. Geophys. Res., 111, D02206, https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2004JD005694

  • Leon, D., G. Vali, and M. Lothon, 2006: Dual-doppler analysis in a single plane from an airborne platform.  Journal of Atmospheric and Oceanic Technology, 23, 3-22. https://journals.ametsoc.org/view/journals/atot/23/1/jtech1820_1.xml

  • Damiani, R., G. Vali, and S. Haimov, 2006: The structure of thermals in cumulus from airborne dual-doppler radar observations.  J. Atmos. Sci., 63, 1432-1450. https://journals.ametsoc.org/view/journals/atsc/63/5/jas3701.1.xml

  • vanZanten, M. C., B. Stevens, G. Vali, et al., 2005: Observations of drizzle in nocturnal marine stratocumulus. J. Atmos. Sci., 62, 88-106. https://journals.ametsoc.org/view/journals/atsc/62/1/jas-3355.1.xml

  • Stevens, B., G. Vali, K. Comstock, et al., 2005: Pockets of open cells and drizzle in marine stratocumulus. Bulletin of the American Meteorological Society, 86, 51-57. https://journals.ametsoc.org/view/journals/bams/86/1/bams-86-1-51.xml

  • Lothon, M., D. H. Lenschow, D. Leon, et al., 2005: Turbulence measurements in marine stratocumulus with airborne doppler radar. Quart. J. Roy. Meteor. Soc., 131, 2063-2080. https://rmets.onlinelibrary.wiley.com/doi/10.1256/qj.04.131

  • "Structure of "non-drizzling" marine stratocumulus." July 23, 2004 presentation at the 14th International Conference on Clouds and Precipitation. Bologna, Italy.

  • "Airborne radar observations of non-drizzling marine stratocumulus. " Paper to be presented at the Intern'l Conference on Clouds and Precipitation, Bologna, July 2004.

  • Stevens, B., D. H. Lenschow, G. Vali, et al., 2003: Dynamics and chemistry of marine stratocumulus --DYCOMS-II. Bulletin of the American Meteorological Society, 84, 579-593. https://journals.ametsoc.org/view/journals/bams/84/5/bams-84-5-579.xml

  • Stevens, B., D. H. Lenschow, I. Faloona, et al., 2003: On entrainment rates in nocturnal marine stratocumulus. Quarterly Journal of the Royal Meteorological Society, 129, 3469-3493. https://rmets.onlinelibrary.wiley.com/doi/10.1256/qj.02.202

  • Wolde M. and G. Vali, 2001: Polarimetric signatures from ice crystals observed at 95 GHz in winter clouds. Part I: Dependence on crystal form. J. Atmos. Sci., 58, 828-841. https://doi.org/10.1175/1520-0469(2001)058<0828:PSFICO>2.0.CO;2

  • Wolde M. and G. Vali, 2001: Polarimetric signatures from ice crystals observed at 95 GHz in winter clouds. Part II: Frequencies of occurrence. J. Atmos. Sci., 58, 842-849. https://doi.org/10.1175/1520-0469(2001)058<0842:PSFICO>2.0.CO;2

  • Wolde, M. and G. Vali, 2001: Cloud structure and crystal growth in Nimbostratus.  Atmos. Res., 61, 49-74,

  • "Evaluations of COAMPS forecasts of coastal stratus using satellite microphysical retrievals and aircraft measurements." by Melanie A. Wetzel, William T. Thompson, Gabor Vali, Steven K. Chai, Tracy Haack, Marcin J. Szumowski and Robert Kelly. Weath. and Forecasting,16, 588-599, 2001.

  • "Observations of microphysics pertaining to the development of drizzle in warm, shallow cumulus clouds" by J.R. French, G. Vali and R.D. Kelly, Quart. J. Roy. Meteor. Soc., 126, 415-443, 2000.

  • "Evolution of small cumulus clouds in Florida: Observations of pulsating growth." by J.R. French, G. Vali and R.D. Kelly, Atmos. Res. 52, 143-165, 1999.

  • "Finescale structure and microphysics of coastal stratus." by G. Vali, R.D. Kelly, J. French, S. Haimov, D. Leon, R.E. McIntosh and A. Pazmany, J. Atmos. Sci., 55, 3540-3564, 1998. https://doi.org/10.1175/1520-0469(1998)055<3540:FSAMOC>2.0.CO;2

  • "Retrieval of three-dimensional particle velocities from airborne Doppler radar data" by D. Leon and G. Vali, J. Atmos. Oceanic Technol., 15, 860-870, 1998. https://journals.ametsoc.org/view/journals/atot/15/4/1520-0426_1998_015_0860_rotdpv_2_0_co_2.xml

  • "Detection of ice hydrometeor alignment using an airborne W-band polarimetric radar". by J. Galloway, A. Pazmany, J. Mead, R.E. McIntosh, D. Leon, J. French, R. Kelly and G. Vali, J. Atmos. Oceanic Technol., 14, 3-12, 1997.  https://journals.ametsoc.org/view/journals/atot/14/1/1520-0426_1997_014_0003_doihau_2_0_co_2.xml

  • "Airborne radar and in-situ observations of a shallow stratus with drizzle" by G. Vali, R. Kelly, A. Pazmany and R.E. McIntosh. Atmos. Res., 38, 361-380, 1995. https://www.sciencedirect.com/science/article/pii/016980959500006D

  • "An airborne 95 GHz polarimetric radar for cloud studies". by A. Pazmany, R.E. McIntosh, R. Kelly and G. Vali. IEEE Trans. Geosci. Remote Sensing , 32, 731-739. 1994 https://ieeexplore.ieee.org/document/298002
• Various

  • "Rain and Snow - Water and Ice." Talk given at the Western Wyoming Community College, January 31, 2008.

  • "What global climate change means?" Talk given as part of the Focus the Nation program, Rock Springs, WY. January 31, 2008.

  • "What will the doctor prescribe? - A look at weather modification."  January 31, 2007 talk given at the reception for the International Symposium on Weather Modification. Tsukuba, Japan. 

  • "Reflections on PEP-SSP3 and the status os weather modification efforts." Talk given in Valladolid, Spain, May 7, 2005.

  • "Aerosols: Direct and Indirect Effects ." Chapter 5 of IPCC Working Group I: The scientific basis.

  • "Wanted: More PhDs. Graduate Enrollments in the Atmospheric Sciences." by G. Vali, R. Anthes, D. Thomson, D. Houghton, J. Fellows and S. Warner. Bull. Amer. Meteorol. Soc., 83, 63-71, 2002.

  • "A balloon-borne cloud condensation nuclei counter" by D.J. Delene, T. Deshler, P. Wechsler and G. Vali. J. Geophys. Res., 103, 8927-8934, 1998.

  • "Calibration of a photoelectric cloud condensation nucleus counter" by J.C. Parente de Oliviera and G. Vali. Atmos. Res., 38, 237-248. 1995.

  • "Sulfur dioxide oxidation in wintertime orographic cap clouds." by J.R. Snider and G. Vali. J. Geophys. Res. (Atm.), 99, 18713-18733. 1994.

UWYO DYCOMS Project Reports:

• LWC instrument comparisons. Posted October 6, 2004.

• Summary of findings for rf05. Paper for the International Cloud Physics Conference, 2004. Posted March 17, 2004.

• rf01 no drizzle portion. Images and statistics of reflectivity and vertical velocity for the non-drizzling portion of RL2, 1155-1207 UTC.

• rf07 reflectivity pdfs given here show that the drizzle rate decreased during the night between 0800 and 1400 UTC. Posted September 24, 2003.

• "Indentifying drizzle within marine stratus with W-band radar reflectivity profiles." S. thesis by Wang, Jingyun. Posted: June 6, 2003.

• Circle images linked here are for one of the circle patterns from each flight. The images depict radar reflectivity from the nadir beam of the W-band instrument on the C-130. Posted February 7, 2003.

• rf05 - Flow field in the radar scan plane. Images found under this link show the results of the dual-Doppler analyses for the 10:30 to 10:58 circle. There are 15 pages of it. The flight altitude was 998 m. The grid spacing for these analyses is 25 m in the vertical and 22 m in the horizontal, though only every third point in the horizontal is shown in the figures. The images have roughly 2:1 horizontal to vertical aspect ratios. The horizontal winds represent the local deviation of the wind from the large-scale average in the vertical plane extendig down from the flight path. The narrower strips contain images of the reflectivity field and of the vertical velocity at 1:1 aspect ratio. The abscissa for these plots is the azimuth angle of the quasi-circular flight track, but time is also given. These analyses were done and the images were produced by David Leon.    Posted: December 5, 2002.

• "Rain rate - reflectivity relationship for marine stratus"S. thesis by Qing Yang. Posted: December 5, 2002.

• rf05 - Case of minumum drizzle. Part 2. Posted: September 13, 2002.

• rf05 - Case of minumum drizzle. Part 1. Posted: May 25, 2002.   Revised May 29, 2002.

• Z-R relationship from in-situ probe data. Posted: May 5, 2002.

• Reference hydrometeor distributions.

NOTE: Much of the material is based on work supported by the National Science Foundation under Grant No. 0094956 and others. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

 

Past Professional Activities:

• 1970: Participant for "Review Report on Weather Modification", for the Canada Department of Agriculture.

• 1973: Participated in the writing of the AMS/NSF Cloud Physics Review.

• 1975: Organized and chaired at the University of Wyoming the Third International Workshop on Ice Nucleation Measurement. This workshop was held under the auspices of the Committee on Nucleation of the International Commission for Cloud Physics.

• 1975: Local host for AMS Symposium on the Prediction and Measurement of Ice Crystal Concentrations in Clouds.

• 1975-1977: Member, AMS Cloud Physics Committee

• 1976: Chair, Review Panel for NCAR's Research Aviation Facility

• 1976-1979: Member, Committee on Aerobiology, National Research Council, National Academy of Sciences.

• 1977: Chair, AMS Cloud Physics Committee

• 1977: Sabbatical (one semester) - Commonwealth Scientific and Research Organization, Cloud Physics Division, Sydney, Australia.

• 1978: Participant, Atmospheric Research Review Workshop for the NRC Committee on Atmospheric Sciences

• 1980-1982: Member, AMS Committee on Weather Modification

• 1980-1988: Chairman, Committee on Nucleation and Atmospheric Aerosols; International Commission on Cloud Physics International Association for Meteorology and Atmospheric Physics, IUGG.

• 1982-1983: Chair, Scientific Program Evaluations Committee of the University Corporation for Atmospheric Research.

• 1983: Reviewer, for Task Groups A, B, C, and D of the National Acid Precipitation Assessment Program.

• 1983: Participant, Discussion Seminar on Precipitation Management, organized by the National Research Council for the Agency for International Development.

• 1984: Co-Chairman, XI International Conference on Atmospheric Aerosols, Condensation and Ice Nuclei. Budapest, Hungary.

• 1985: Guest editor of "Journal de Recherches Atmospheriques" Special Issue.

• 1985: Invited Lecturer at the "Autumn Workshop in Cloud Physics and Climate", International Centre for Theoretical Physics, Trieste, Italy.

• 1986: Co-Author: "Report to the Office of Technology Assessment on the impact of ice-nucleating bacteria on crops".

• 1986-1987: Sabbatical leave (one year): Theta Associates. Short courses on cloud physics and weather modification given in Casablanca, Morocco and ; Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado; Centre National de Recherche Meteorologique, Toulouse, France.

• 1987: Invited Lecturer at the "Second Autumn Workshop in Cloud Physics and Climate", International Centre for Theoretical Physics, Trieste, Italy.

• 1987-1991: Co-Chair, International Aerosol Climatology Project (sponsored by Int'l Commission on Clouds and Precipitation and by the Int'l Radiation Commission; IAMAP, IUGG). Chairman, Sub-Working Group #2 on Aerosol-Cloud Interactions.

• 1988: Lecturer, Chiang Mai, Thailand, US Bureau of Reclamation short course on weather modification.

• 1990: Invited participant -- Workshop on Precipitation Physics of Tropical Convective Systems. Fortaleza. Brazil.

• 1990: Invited participant -- Review meeting of the findings and recommendations of SACPEX I. World Meteorological Organization, Geneva, Switzerland.

• 1988-1992: Member, Advisory Committee for Atmospheric Sciences, National Science Foundation.

• 1988-1992: Editor, Journal of Applied Meteorology (American Meteorological Society).

• 1989-1993: Member, UCAR/UNIDATA Policy Committee

• 1993: Organizer - "Sixth International Conference on Biological Ice Nucleation", Laramie, Wyoming, August 4-6, 1993

• 1993: Member, Steering Committee for "Role of Clouds Energy and Water (ROCEW)", NSF.

• 1994: Member, Long-Range Planning Committee, NSF/ATM.

• 1994-1995: Sabbatical leave (academic year): Fulbright Scholar, Visiting Professor at the Department of Analytical Chemistry, University of Veszprem, Hungary. Visiting lecturer at the Eotvos Lorand University, Budapest, Hungary.

• 1995: Invited expert to the Precipitation Enhancement Workshop conducted under the auspices of the Multilateral Water Resources Group in support of the Middle East Peace Process. Terrigal, Australia.

• 1996: Invited expert to symposium on "Theoretical and Practical Aspects of a Regional Precipitation Enhancement Program for the Middle East and Mediterranean". Sponsored by the European Union. Bari, Italy.

• 1997: Invited participant at the "WMO Workshop on Measurements of Cloud Properties for Forecasts of Weather" held in Mexico City, Mexico

• 1999: Invited participant at the "Workshop on Warm Rain Modification." Sponsored by the World Meteorological Organization and the State of Durango. Mazatlan, Mexico.

• 1996-2000: Vice-President, International Commission on Clouds and Precipitation, IAMAS/IUGG

• 2001: Guest Editor, Special Issue of the journal "Atmospheric Research".

• Board of Trustees, University Corporation for Atmospheric Research (first elected 1997-2000; reelected 2001-2004).

• 2002-2003: Reviewer of "Critical Issues in Weather Modification Research" report by the Committee on the Status and Future Directions in U.S Weather Modification Research and Operations, National Research Council. National Academies Press.

• 2005-2006: Evaluator for the WMO/UAE International Prize for Weather Modification.

• 2002-2012: Member of World Meteorological Organization Expert Team on Weather Modification Research (and its predecessor Panels).