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Peter H. Daum


Daum retired from the Environmental & Climate Sciences Department in January 2013 and was named Scientist Emeritus. During his 32 years in the department, he served as Department Chair, Senior Scientist, and manager of the Department’s DOE project "Influence of Aerosols and Clouds on Climate and Climate Forcing”.  His scientific work focused on understanding the processes that are needed to represent the direct and indirect effects of aerosols on climate. Emphasis was on observation and analysis of aerosol and cloud microphysical properties and their interactions, and on the chemical, physical, and meteorological processes that govern their impact on the Earth’s energy-balance. Much of this research had been conducted in the context of large multi-agency, interdisciplinary field programs. 

Recent programs in which he has had a major role include the 2005 Marine Stratocumulus Experiment (MASE) to study the microphysical properties of stratus clouds off the coast of northern California; the MaxMex project in 2006 to study of the evolution of aerosol properties in the Mexico City urban plume and; the 2008 VOCALS study of the factors that determine the properties and persistence of marine stratus clouds off the west coast of South America. This research has resulted in the publication of over 100 papers in the peer-reviewed scientific literature on a broad range of topics in atmospheric chemistry and physics.

Daum was recipient of the 2002 Southampton College Environmental Leadership award for his research in Atmospheric Sciences.


  • Michigan State University, Ph.D., Chemistry
  • Drexel Institute of Technology, B.S., Chemistry


  • American Geophysical Union

Research Interests

  • Atmospheric chemistry
  • Cloud/aerosol microphysics and optics
  • Cloud radiative properties


  • Chair, Environmental & Climate Sciences Department, January 2008-January 2013
  • Senior Scientist, October 2008-present
  • Head, Atmospheric Sciences Division, September 2000-January, 2008
  • Chemist, Atmospheric Sciences Division, Brookhaven National Laboratory, 1980-2000
  • Visiting Professor, University of North Carolina at Chapel Hill, 1978-79
  • Department of Chemistry, Northern Illinois University, Dekalb, IL.
    1969-75 (Assistant Professor), 1975-80 (Associate Professor with tenure)

External Service

  • National Science Foundation (NSF) and NOAA Review Panels
  • Independent Technical Advisory Committee (ITAC) TCEQ Air Quality Research Program (2009-Present)
  • Texas Air Research Program Advisory Board (2007-Present)
  • Member ICARTT Steering Committee (ICART was a multi-agency international experiment conducted in Summer 2004) (2002-2005)
  • Executive Committee TexAQS 2006 Study (2003-2006)
  • University of Houston, Air Quality Group Advisory Panel (2001-2004)
  • Houston Area Research Corporation (HARC) Scientific Advisory Panel (2001-2006)

Publications (since 2005)

Liu, Y., Daum, P. H., and Lu, C. Comment on “Cloud droplet spectral width relationship to CCN spectra and vertical velocity” by Hudson et al. J. Geophys. Res. Atmos. 118, online, doi:10.1002/2012JD019207 (2014).

Lee, Y.-N., Springston, S., Jayne, J., Wang, J., Hubbe, J., Senum, G., Kleinman, L., and Daum, P. Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign. Atmos. Chem. Phys. Discuss. 13, 26043-26115, doi:10.5194/acpd-13-26043-2013 (2013).

Min, Q., Joseph, E., Lin, Y., Min, L., Yin, B., Daum, P. H., Kleinman, L. I., Wang, J., and Lee, Y.-N. Validation of MODIS cloud microphysical properties with in situ measurements over the Southeast Pacific. Atmos. Chem. Phys. Discuss. 12, 1419-1449, doi:10.5194/acpd-12-1419-2012 (2012).

Kleinman, L. I., Daum, P. H., Lee, Y.-N., Lewis, E. R., Sedlacek III, A. J., Senum, G. I., Springston, S. R., Wang, J., Hubbe, J., Jayne, J., Min, Q., Yum, S. S., and Allen, G. Aerosol concentration and size distribution measured below, in, and above cloud from the DOE G-1 during VOCALS-REx. Atmos. Chem. Phys. Discuss. 11, 17289-17336, doi:10.5194/acpd-11-17289-2011 (2011).

Wood, R., Mechoso, C. R., Bretherton, C. S., Weller, R. A., Huebert, B., Straneo, F., Albrecht, B. A., Coe, H., Allen, G., Vaughan, G., Daum, P., Fairall, C., Chand, D., Klenner, L. G., Garreaud, R., Grados, C., Covert, D. S., Bates, T. S., Krejci, R., Russell, L. M., Szoeke, S. d., Brewer, A., Yuter, S. E., Springston, S. R., Chaigneau, A., Toniazzo, T., Minnis, P., Palikonda, R., Abel, S. J., Brown, W. O. J., Williams, S., Fochesatto, J., Brioude, J., and Bower, K. N. The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx): goals, platforms, and field operations. Atmos. Chem. Phys. 11, 627–654, doi:10.5194/acp-11-627-2011 (2011).

Kleinman, L. I., Springston, S. R., Wang, J., Daum, P. H., Lee, Y.-N., Nunnermacker, L. J., Senum, G. I., Weinstein-Lloyd, J., Alexander, M. L., Hubbe, J., Ortega, J., Zaveri, R. A., Canagaratna, M. R., and Jayne, J. The time evolution of aerosol size distribution over the Mexico City plateau. Atmos. Chem. Phys. 9, 4261-4278 (2009).

Wang, J., Daum, P. H., Yum, S. S., Liu, Y., Senum, G. I., Lu, M.-L., Seinfeld, J. H., and Jonsson, H. Observations of marine stratocumulus microphysics and implications for processes controlling droplet spectra: Results from the Marine Stratus/Stratocumulus Experiment (MASE). J. Geophys. Res. 114, D18210, doi:10.1029/2008JD011035 (2009).

Guo, H., Liu, Y., Daum, P. H., and Tao, W.-K. Characteristics of vertical velocity in marine stratocumulus: Comparison of LES simulations with observations. Environ. Res. Lett. 3, 045020, doi:10.1088/1748-9326/3/4/045020 (2008).

Guo, H., Liu, Y., Daum, P. H., Zeng, X., Li, X., and Tao, W.-K. Effects of model resolutions on entrainment (inversion heights), cloud-radiation interactions, and cloud radiative forcing. Atmos. Chem. Phys. Discuss. 8, 20399–20425 (2008).

Liu, Y., Daum, P. H., McGraw, R., Miller, M., and Niu, S. Correction to "Theoretical expression for autoconversion rate of cloud droplet number concentration." Geophys. Res. Lettrs 35, L04806, doi:10.1029/2008GL033290 (2008).

Liu, Y. and Daum, P. H. Relationship of refractive index to mass density and self-consistency of mixing rules for multicomponent mixtures like ambient aerosols J. Aerosol Sci. 39, 974–986, doi:10.1016/j.jaerosci.2008.06.006 (2008).

Liu, Y., P. H. Daum, and S. Yum, Ship tracks revisited: New understanding and cloud parameterization. Asia-pacific J. Atmos. Sci., 44, 1-9 (2008).

Liu, Y., Daum, P. H., Guo, H., and Peng, Y. Dispersion bias, dispersion effect, and aerosol-cloud conundrum. Environ. Res. Lettrs, Aerosol Precipitation Special Issue 3, 045021, doi:10.1088/1748-9326/3/4/045021 (2008).

Nunnermacker, L. J., Weinstein-Lloyd, J. B., Hillery, B., Giebel, B., Kleinman, L. I., Springston, S. R., Daum, P. H., Gaffney, J., Marley, N., and Huey, G. Aircraft and ground-based measurements of hydroperoxides during the 2006 MILAGRO field campaign. Atmos. Chem. Phys. 8, 7619-7636 (2008).

Wang, J., Lee, Y.-N., Daum, P. H., Jayne, J., and Alexander, M. L. Effects of aerosol organics on cloud condensation nucleus (CCN) concentration and first indirect aerosol effect. Atmos. Chem. Phys. 8, 6325-6339 (2008).

Kleinman, L. I., Daum, P. H., Lee, Y.-N., Senum, G. I., Springston, S. R., Wang, J., Berkowitz, C., Hubbe, J., Zaveri, R. A., Brechtel, F. J., Jayne, J., Onasch, T. B., and Worsnop, D. Aircraft observations of aerosol composition and ageing in New England and Mid-Atlantic states during the summer 2002 NEAQS Field Campaign. J. Geophys. Res. 112, D09310, doi:10.1029/2006JD007786 (2007).

Liu, Y., P. H. Daum, R. McGraw, M. Miller, and S. Niu, 2007: Theoretical expression for the autoconversion rate of droplet concentration. Geophys. Res. Lett, 34, L16821, doi:10.1029/2007GL030389

Liu, Y., Daum, P. H., McGraw, R., Miller, M., and Niu, S. Theoretical expression for autoconversion rate of cloud droplet number concentration. Geophys. Res. Lettrs 34, L16821, doi:10.1029/2007GL030389 (2007).

Liu, Y., Geerts, B., Miller, M., Daum, P., and McGraw, R. Theoretical expression for radar threshold reflectivity that separates non-precipitating from precipitating clouds. Geophys. Res. Lett, 35, L03807, doi:10.1029/2007GL031201.

Wang, J., Daum, P. H., Kleinman, L. I., Lee, Y.-N., Schwartz, S. E., Springston, S. R., Jonsson, H., Covert, D., and Elleman, R. Observation of ambient aerosol particle growth due to in-cloud processes within boundary layers. J. Geophys. Res. 112, D14207, doi:10.1029/2006JD007989 (2007).

Liu, Y., Daum, P. H., McGraw, R. and Wood, R. Parameterization of the autoconversion process. Part II: Generalization of Sundqvist-type parameterizations. J. Atmos. Sci. 63, 1103-1109 (2006).

Liu, Y., Daum, P.H., and Yum, S.S. 2005: Analytical expression for the relative dispersion of the cloud droplet size distribution, Geophys. Res. Lettrs 33, L02810, doi:10.1029/2005GL024052 (2006).

Liu, Y., P. H. Daum, and R. McGraw, 2005a: Size Truncation Effect, Threshold Behavior, and a New Type of Autoconversion Parameterization. Geophys. Res. Lett, 32, L11811, doi:10.1029/2005GL022636..

Kleinman, L. I., Daum, P. H., Lee, Y.-N., Nunnermacker, L. J., Springston, S. R., Weinstein-Lloyd, J., and Rudolph, J. A comparative study of ozone production in 5 U.S. metropolitan areas. J. Geophys. Res. 110, D02301, doi: 10.1029/2004JD005096 (2005).