Cloud and Precipitation Physics

Cloud and precipitation processes are important for weather and climate. I am interested in understanding these processes, how these processes are manifested in remote sensing observations, and how to best represent these processes in numerical models.

Clouds and precipitation

Clouds and precipitation

One approach to studying microphysics is the use of simplified physical models called process models, in which certain microphysical processes are explored in isolation from other complicating factors. Microphysical processes that I have investigated include those governing the evolution of raindrop spectra in warm clouds (e.g., size sorting, evaporation, coalescence, breakup), particle phase transitions (e.g., melting of hailstones, freezing of raindrops), and particle growth (e.g., vapor deposition of ice crystals).

Another approach is to use more complex models that account for all physical processes as well as the evolving storms themselves. These models more realistically depict an entire storm system and the interactions among storm dynamics, microphysics, and thermodynamics.

Such models can be coupled to observation operators to simulate what a radar would “see” in various circumstances. This allows us to understand how the processes are observed with remote sensing platforms, but also provides a pathway to critically examine and evaluate model microphysics parameterizations.

My publications involving microphysical modeling and/or observations are listed below.


Wu, D., K. Zhao, M. R. Kumjian, X. Chen, H. Huang, M. Wang, A. C. Didlake, Y. Duan, and F. Zhang, 2018: The kinematics and microphysics of convection in the outer rainband of Typhoon Nida (2016) revealed by the polarimetric radar. Monthly Weather Review146, 2147-2159. pdf

Didlake, A. C., and M. R. Kumjian, 2017: Examining polarimetric radar observations of bulk microphysical structures and their relation to vortex kinematics in Hurricane Arthur (2014). Monthly Weather Review, 145, 4521-4541. pdf

Li*, M., F. Zhang, Q. Zhang, J. Harrington, and M. R. Kumjian, 2017: Nonlinear response of hail precipitation rate to environmental moisture content: a real case modeling study of an episodic midlatitude severe convective event. Journal of Geophysical Research – Atmospheres 122, 6729-6747. pdf

Sulia, K. J., and M. R. Kumjian, 2017: Simulated polarimetric fields of ice vapor growth using the adaptive habit model. Part I: Large-eddy simulations. Monthly Weather Review145, 2281-2302pdf

Sulia, K. J., and M. R. Kumjian, 2017: Simulated polarimetric fields of ice vapor growth using the adaptive habit model. Part II: A case study from the FROST experiment. Monthly Weather Review145, 2303-2323. pdf

Dennis*, E. J., and M. R. Kumjian, 2017: The impact of vertical wind shear on hail growth in simulated supercells. Journal of the Atmospheric Sciences74, 641-663pdf

Kumjian, M.R., K. A. Lombardo, 2017: Insights into the evolving microphysical and kinematic structure of Northeastern U.S. winter storms from dual-polarization Doppler radar. Monthly Weather Review145, 1033-1061. pdf

Van Den Broeke, M. S., D. M. Tobin*, and M. R. Kumjian, 2016: Polarimetric radar observations of precipitation type and rate from the 2-3 March 2014 winter storm in Oklahoma and Arkansas. Weather and Forecasting31, 1179-1196.

Schrom*, R. S., and M. R. Kumjian, 2016: Connecting microphysical processes in Colorado winter storms with vertical profiles of radar observations. Journal of Applied Meteorology and Climatology, 55, 1771-1787pdf

Giangrande, S. E., T. Toto, A. Bansemer, M. R. Kumjian, S. Mishra, and A. V. Ryzhkov, 2016: Insights into riming and aggregation processes as revealed by aircraft, radar, and disdrometer observations for a 27 April 2011 widespread precipitation event. Journal of Geophysical Research – Atmospheres121, 5846-5863. pdf

Kumjian, M. R., S. Mishra, S. E. Giangrande, T. Toto, A. Ryzhkov, and A. Bansemer, 2016: Polarimetric radar and aircraft observations of saggy bright bands during MC3E. Journal of Geophysical Research – Atmospheres121, 3584-3607. doi:10.1002/2015JD024446pdf

Schrom*, R. S., M. R. Kumjian, and Y. Lu, 2015: Polarimetric radar signatures of dendritic growth zones in Colorado winter storms. Journal of Applied Meteorology and Climatology54, 2365-2388pdf

Kumjian, M.R., Z.J. Lebo, and H.C. Morrison, 2015: On the mechanisms of rain formation in an idealized supercell storm. Monthly Weather Review143, 2754-2773. pdf

Oue, M., M.R. Kumjian, Y. Lu, J. Verlinde, K. Aydin, and E.E. Clothiaux, 2015: Linear depolarization ratios of columnar ice crystals in a deep precipitating system over the Arctic observed by zenith-pointing Ka-band Doppler radar. Journal of Applied Meteorology and Climatology54, 1060-1068. pdf

Oue, M., M. R. Kumjian, Y. Lu, Z. Jiang, E. E. Clothiaux, J. Verlinde, and K. Aydin, 2015: X-band polarimetric and Ka-band Doppler spectral radar observations of a graupel-producing Arctic mixed-phase cloud. Journal of Applied Meteorology and Climatology, 54, 1335-1351pdf

Homeyer, C.R., and M.R. Kumjian, 2015: Microphysical characteristics of overshooting convection from polarimetric radar observations. Journal of the Atmospheric Sciences72, 870-891. pdf

Dawson, D. T., E. R. Mansell, and M. R. Kumjian, 2015: Does wind shear cause hydrometeor size sorting? Journal of the Atmospheric Sciences72, 340-348. pdf

Kumjian, M.R., and O.P. Prat, 2014: The impact of raindrop collisional processes on the polarimetric radar variables. Journal of the Atmospheric Sciences71, 3052-3067. pdf

Kumjian, M.R., A. P. Khain, N. Benmoshe, E. Ilotoviz, A.V. Ryzhkov, and V. T. J. Phillips, 2014: The anatomy and physics of ZDR columns: Investigating a polarimetric radar signature with a spectral bin microphysical model. Journal of Applied Meteorology and Climatology53, 1820-1843. pdf

Dawson, D.T., E.R. Mansell, Y. Jung, L.J. Wicker, M.R. Kumjian, and M. Xue, 2014: Low-level ZDR signatures in supercell forward flanks: the role of size sorting and melting of hail. Journal of the Atmospheric Sciences71, 276-299. pdf

Ryzhkov, A.V., M.R. Kumjian, S.M. Ganson, and P. Zhang, 2013: Polarimetric radar characteristics of melting hail. Part II: Practical applications. J. Applied Meteorology and Climatology52, 2871-2886pdf

Ryzhkov, A.V., M.R. Kumjian, S.M. Ganson, and A.P. Khain, 2013: Polarimetric radar characteristics of melting hail. Part I: Theoretical simulations using spectral microphysical modeling. J. Applied Meteorology and Climatology52, 2849-2870pdf

Trömel, S., M.R. Kumjian, A.V. Ryzhkov, C. Simmer, and M. Diederich, 2013: Backscatter differential phase – estimation and variability. Journal of Applied Meteorology and Climatology52, 2529-2548pdf

Andrić, J., M.R. Kumjian, D.S. Zrnić, J.M. Straka, and V. Melnikov, 2013: Polarimetric signatures above the melting layer in winter storms: An observational and modeling study. Journal of Applied Meteorology and Climatology, 52, 682-700pdf

Kumjian, M.R., S. Gansonand A.V. Ryzhkov, 2012: Raindrop freezing in deep convective updrafts: A microphysical and polarimetric model. Journal of the Atmospheric Sciences69, 3471-3490pdf

Kumjian, M.R., and A.V. Ryzhkov, 2012: The impact of size sorting on the polarimetric radar variables.  Journal of the Atmospheric Sciences69, 2042-2060pdf

Kumjian, M.R. and A.V. Ryzhkov, 2010: The impact of evaporation on polarimetric characteristics of rain: Theoretical model and practical implications.  Journal of Applied Meteorology and Climatology49, 1247-1267. pdf

Kumjian, M.R. and A.V. Ryzhkov, 2009:  Storm-relative helicity revealed from polarimetric radar observations.  Journal of the Atmospheric Sciences66, 667–685. pdf


* Indicates a student supervised by Dr. Kumjian.