Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 16 Observation, Prediction and Verification of Precipitation (EGU Session 2007) 2008 10.5194/adgeo-16-11-2008 http://www.adv-geosci.net/16/11/2008/ http://www.adv-geosci.net/16/11/2008/adgeo-16-11-2008.html http://www.adv-geosci.net/16/11/2008/adgeo-16-11-2008.pdf 11 17 2008-04-09 Precipitation classification at mid-latitudes in terms of drop size distribution parameters C. Caracciolo caracciolo@fe.infn.it F. Porcù F. Prodi Department of Physics, University of Ferrara, Italy Institute of Atmospheric Sciences and Climate of the Italian National Research Council (ISAC-CNR), Bologna, Italy The drop size distribution (DSD) is a fundamental property of rainfall because the shape of the distribution reflects the physics of rain formation processes. Given the lack of studies on the DSD at mid-latitudes, the present work focuses on the microphysical characterization of precipitation events occurring in Italy, using two different types of disdrometer. A large number of different rain events was collected: they underwent microphysical analysis by computing the Z-R relationships, observing the average DSDs and DSD parameters, fitting the real distribution for different rainfall rate categories and applying convective (C) – stratiform (S) discrimination algorithms. A general agreement with past works at mid-latitudes is found both in the Z-R relationship and in DSD parameters. The rain distribution is well described by a gamma DSD and only in some cases (especially the light rain events) by an exponential DSD. Marked differences are observed in DSD parameters and Z-R relationships between C and S episodes. The use of disdrometers for areas covered by multiparametric radar is suggested and will be performed in the near future. Caracciolo C., Prodi, F., Battaglia, A., and Porc\`u, F.: Analysis of the moments and parameters of a gamma DSD to infer precipitation properties: a convective stratiform discrimination algorithm, Atm. Res., 80(2–3), 165–186, 2006a. Caracciolo C., Prodi, F., and Uijlenhoet, R.: Comparison between Pludix and impact/optical disdrometers during rainfall measurement campaigns, Atm. Res., 82(1–4), 137–163, 2006b. Caracciolo C., Prodi, F., and Casazza, M.: Atmospheric precipitation analysis using both disdrometric and satellite data for desertification studies, Proc. ERAD Conference 2006, 191–194, 2006c. Doviak, R. J. and Zrnic, D. S.: Doppler radar and weather observations, Academic Press, California, 1993. Fujiwara, M.: Raindrop size distribution from individual storms, J. Atmos. Sci., 22, 585–591, 1965. Jones, D. M. A.: Rainfall drop size distribution and radar reflectivity, Rep. No. 6, Illinois State Water Survey, Urbana, IL, 20 pp., 1956. Joss, J. and Waldvogel, A.: Ein Spektrograph fuer Niederschlagstropfen mit automatischer Auswertung, Pure Appl. Geophys., 68, 240–246, 1967. Joss, J. and Waldvogel, A.: Raindrop size distribution and sampling size errors, J. Atmos. Sci., 26, 566–569, 1969. Krajewski W. F., Kruger, A., Caracciolo, C., Golé, P., Barthes, L., Creutin, J.-D., Delahaye, J.-Y., Nikolopoulos, E. I., Ogden, F., Vinson, J.-P.: DEVEX-Disdrometer Evaluation Experiment: Basic results and implications for hydrologic studies, Adv. in Water Res., 29, 311–325, 2006. Marshall, J. S. and Palmer, W. M.: The distribution of raindrops with size, J. Meteor., 5, 165–166, 1948. Prodi, F., A. Tagliavini, F. Pasqualucci: Time variability in rainfall events observed by Pludix, Phys. Chem. Earth (B), 25(10–12), 959–963, 2000. Testud J., Oury, S., Blank, R. A., Amayenc, P., Dou, X.: The concept of "Normalized" distribution to describe raindrop spectra: a tool for cloud physics and cloud remote sensing, J. Appl. Met., 40, 1118–1140, 2001. Tokay, A. and Short, D.: Evidence from tropical raindrop spectra of the origin of rain from stratiform versus convective, J. Appl. Meteor., 35, 355–371, 1996. Ulbrich, C.: Natural Variations in the analytical form of the raindrop size distribution, J. Clim. and Appl. Meterol., 22, 1764–1775, 1983. Waldvogel, A.: The N$_0$ jump of raindrop spectra, J. Atmos. Sci., 31, 1067–1078, 1974. Wolff D. B., Marks, D. A., Amitai, E., Silberstein, D. S., Fisher, B. L., Tokay, A., Wang, J., and Pippitt, J. L.: Ground validation for the Tropical Rainfall Measuring Mission (TRMM), J. Atmos. Ocean. Technol., 22, 365–380, 2005. Zawadski I., Monteiro, E., and Fabry, F.: The development of drop size distributions in light rain, J. Atm. Sci., 51, 1100–1113, 1994.