• Anagnostou, M. N., Anagnostou E. N. , Vivekanandan J. , and Ogden F. L. , 2008: Comparison of two raindrop size distribution retrieval algorithms for X-band dual polarization observations. J. Hydrometeor., 9, 589600, doi:10.1175/2007JHM904.1.

    • Search Google Scholar
    • Export Citation
  • Borowska, L., Zrnić D. , Ryzhkov A. , Zhang P. , and Simmer C. , 2011: Polarimetric estimates of a 1-month accumulation of light rain with a 3-cm wavelength radar. J. Hydrometeor., 12, 10241039, doi:10.1175/2011JHM1339.1.

    • Search Google Scholar
    • Export Citation
  • Brandes, E. A., Zhang G. , and Vivekanandan J. , 2002: Experiments in rainfall estimation with a polarimetric radar in a subtropical environment. J. Appl. Meteor., 41, 674685, doi:10.1175/1520-0450(2002)041<0674:EIREWA>2.0.CO;2; Corrigendum, 44, 186, doi:10.1175/1520-0450(2005)44<186:C>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Brandes, E. A., Zhang G. , and Vivekanandan J. , 2004: Drop size distribution retrieval with polarimetric radar: Model and application. J. Appl. Meteor., 43, 461475, doi:10.1175/1520-0450(2004)043<0461:DSDRWP>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Bringi, V., and Chandrasekar V. , 2001: Polarimetric Doppler Weather Radar: Principles and Applications. Cambridge University Press, 636 pp.

  • Cao, Q., and Qi Y. , 2014: The variability of vertical structure of precipitation in Huaihe River Basin of China: Implications from long-term spaceborne observations with TRMM precipitation radar. Water Resour. Res., 50, 36903705, doi:10.1002/2013WR014555.

    • Search Google Scholar
    • Export Citation
  • Comstock, K. K., Wood R. , Yuter S. E. , and Bretherton C. S. , 2004: Reflectivity and rain rate in and below drizzling stratocumulus. Quart. J. Roy. Meteor. Soc., 130, 28912918, doi:10.1256/qj.03.187.

    • Search Google Scholar
    • Export Citation
  • Dawson, D. T., Xue M. , Milbrandt J. A. , and Yau M. K. , 2010: Comparison of evaporation and cold pool development between single-moment and multimoment bulk microphysics schemes in idealized simulations of tornadic thunderstorms. Mon. Wea. Rev., 138, 11521171, doi:10.1175/2009MWR2956.1.

    • Search Google Scholar
    • Export Citation
  • Diederich, M., Ryzhkov A. , Simmer C. , Zhang P. , and Trömel S. , 2015: Use of specific attenuation for rainfall measurement at X-band radar wavelengths. Part I: Radar calibration and partial beam blockage estimation. J. Hydrometeor., 16, 487502, doi:10.1175/JHM-D-14-0066.1.

    • Search Google Scholar
    • Export Citation
  • Engerer, N. A., Stensrud D. J. , and Coniglio M. C. , 2008: Surface characteristics of observed cold pools. Mon. Wea. Rev., 136, 48394849, doi:10.1175/2008MWR2528.1.

    • Search Google Scholar
    • Export Citation
  • Gorgucci, E., Chandrasekar V. , and Baldini L. , 2008: Microphysical retrievals from dual-polarization radar measurements at X band. J. Atmos. Oceanic Technol., 25, 729741, doi:10.1175/2007JTECHA971.1.

    • Search Google Scholar
    • Export Citation
  • Gori, E. G., and Joss J. , 1980: Changes of shape of raindrop size distributions simultaneously observed along a mountain slope. J. Rech. Atmos., 14, 239300.

    • Search Google Scholar
    • Export Citation
  • Houze, R. A. J., 1977: Structure and dynamics of a tropical squall-line system. Mon. Wea. Rev., 105, 15401567, doi:10.1175/1520-0493(1977)105<1540:SADOAT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Hu, Z., and Srivastava R. C. , 1995: Evolution of raindrop size distribution by coalescence, breakup, and evaporation: Theory and observations. J. Atmos. Sci., 52, 17611783, doi:10.1175/1520-0469(1995)052<1761:EORSDB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Kim, D. S., Maki M. , and Lee D. I. , 2010: Retrieval of three-dimensional raindrop size distribution using X-band polarimetric radar data. J. Atmos. Oceanic Technol., 27, 12651285, doi:10.1175/2010JTECHA1407.1.

    • Search Google Scholar
    • Export Citation
  • Kneifel, S., Maahn M. , Peters G. , and Simmer C. , 2011: Observation of snowfall with a low-power FM-CW K-band radar (Micro Rain Radar). Meteor. Atmos. Phys., 113, 7587, doi:10.1007/s00703-011-0142-z.

    • Search Google Scholar
    • Export Citation
  • Kumjian, M. R., and Ryzhkov A. V. , 2010: The impact of evaporation on polarimetric characteristics of rain: Theoretical model and practical implications. J. Appl. Meteor. Climatol., 49, 12471267, doi:10.1175/2010JAMC2243.1.

    • Search Google Scholar
    • Export Citation
  • Kumjian, M. R., and Prat O. P. , 2014: The impact of raindrop collisional processes on the polarimetric radar variables. J. Atmos. Sci., 71, 30523067, doi:10.1175/JAS-D-13-0357.1.

    • Search Google Scholar
    • Export Citation
  • Li, X., and Srivastava R. C. , 2001: An analytical solution for raindrop evaporation and its application to radar rainfall measurements. J. Appl. Meteor., 40, 16071616, doi:10.1175/1520-0450(2001)040<1607:AASFRE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mishchenko, M. I., 2000: Calculation of the amplitude matrix for a nonspherical particle in a fixed orientation. Appl. Opt., 39, 10261031, doi:10.1364/AO.39.001026.

    • Search Google Scholar
    • Export Citation
  • Penide, G., Kumar V. V. , Protat A. , and May P. T. , 2013: Statistics of drop size distribution parameters and rain rates for stratiform and convective precipitation during the north Australian wet season. Mon. Wea. Rev., 141, 32223237, doi:10.1175/MWR-D-12-00262.1.

    • Search Google Scholar
    • Export Citation
  • Prat, O. P., and Barros A. P. , 2007: A robust numerical solution of the stochastic collection–breakup equation for warm rain. J. Appl. Meteor. Climatol., 46, 14801497, doi:10.1175/JAM2544.1.

    • Search Google Scholar
    • Export Citation
  • Pruppacher, H. R., and Klett J. D. , 1997: Microphysics of Clouds and Precipitation. Kluwer Academics, 594 pp.

  • Rasmussen, R. M., and Heymsfield A. J. , 1987: Melting and shedding of graupel and hail. Part I: Model physics. J. Atmos. Sci., 44, 27542763, doi:10.1175/1520-0469(1987)044<2754:MASOGA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Rogers, R. R., and Yau M. K. , 1989: A Short Course in Cloud Physics. 3rd ed. Elsevier Press, 290 pp.

  • Rosenfeld, D., and Mintz Y. , 1988: Evaporation of rain falling from convective clouds as derived from radar measurements. J. Appl. Meteor., 27, 209215, doi:10.1175/1520-0450(1988)027<0209:EORFFC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Ryzhkov, A. V., Giangrande S. E. , Melnikov V. M. , and Schuur T. J. , 2005: Calibration issues of dual-polarization radar measurements. J. Atmos. Oceanic Technol., 22, 11381155, doi:10.1175/JTECH1772.1.

    • Search Google Scholar
    • Export Citation
  • Saavedra, P., Battaglia A. , and Simmer C. , 2012: Partitioning of cloud water and rainwater content by ground-based observations with the Advanced Microwave Radiometer for Rain Identification (ADMIRARI) in synergy with a micro rain radar. J. Geophys. Res., 117, D05203, doi:10.1029/2011JD016579.

    • Search Google Scholar
    • Export Citation
  • Seifert, A., 2008: On the parameterization of evaporation of raindrops as simulated by a one-dimensional rainshaft model. J. Atmos. Sci., 65, 36083619, doi:10.1175/2008JAS2586.1.

    • Search Google Scholar
    • Export Citation
  • Srivastava, R. C., 1985: A simple model of evaporatively driven downdraft: Application to microburst downdraft. J. Atmos. Sci., 42, 10041023, doi:10.1175/1520-0469(1985)042<1004:ASMOED>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Srivastava, R. C., 1987: A model of intense downdrafts driven by the melting and evaporation of precipitation. J. Atmos. Sci., 44, 17521774, doi:10.1175/1520-0469(1987)044<1752:AMOIDD>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Testud, J., Oury S. , Black R. A. , Amayenc P. , and Dou X. , 2001: The concept of “normalized” distribution to describe raindrop spectra: A tool for cloud physics and cloud remote sensing. J. Appl. Meteor., 40, 11181140, doi:10.1175/1520-0450(2001)040<1118:TCONDT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Willis, P. T., 1984: Functional fits to some observed drop size distributions and parameterization of rain. J. Atmos. Sci., 41, 16481661, doi:10.1175/1520-0469(1984)041<1648:FFTSOD>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Zhang, G., Vivekanandan J. , and Brandes E. , 2001: A method for estimating rain rate and drop size distribution from polarimetric radar measurements. IEEE Trans. Geosci. Remote Sens., 39, 830841, doi:10.1109/36.917906.

    • Search Google Scholar
    • Export Citation
  • Zipser, E. J., 1969: The role of organized unsaturated convective downdrafts in the structure and rapid decay of an equatorial disturbance. J. Appl. Meteor., 8, 799814, doi:10.1175/1520-0450(1969)008<0799:TROOUC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 373 239 0
PDF Downloads 274 158 0

Radar Observation of Evaporation and Implications for Quantitative Precipitation and Cooling Rate Estimation

View More View Less
  • 1 Meteorological Institute, University of Bonn, Bonn, Germany
  • | 2 Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, and NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma
Restricted access

Abstract

This study analyzes radar observations of evaporation in rain and investigates its impact on surface rainfall and atmospheric cooling rates. A 1D model is used to examine the impact of raindrop evaporation on the evolution of the initial raindrop size distribution (DSD), the resulting reflectivity (Z), and differential reflectivity (ZDR) and surface rain rates. Raindrop evaporation leads to a decrease of Z and an increase of ZDR toward the surface because of the depletion of small raindrops that evaporate first and thus enhance the mean raindrop size. The latter effect, however, can be reduced because of the increasing temperature toward the surface and may even lead to a decrease of ZDR toward the surface. Two events with significant rain evaporation, observed simultaneously by a polarimetric X-band radar and a K-band Micro Rain Radar (MRR), offer quite detailed insight into the evaporation process. During the first event, which exhibits an initial ZDR > 1.5 dB in the upper rain column, raindrops undergo relatively weak evaporation as deduced from the decrease of the small raindrop fraction observed by the MRR. The second event is characterized by a lower initial ZDR < 0.5 dB with all raindrops evaporating before reaching the ground. A retrieval scheme for estimating the evaporation-related cooling rate and surface precipitation from polarimetric radar observations below the bright band is derived based on MRR observations. The algorithm is then used to simulate polarimetric X-band radar observations, which might mitigate uncertainties in the surface rainfall retrievals due to evaporation at far distances from the radars and in the case of beam blocking.

Corresponding author address: Xinxin Xie, Meteorological Institute, University of Bonn, Auf dem Huegel 20, 53121 Bonn, Germany. E-mail: xxie@uni-bonn.de

Abstract

This study analyzes radar observations of evaporation in rain and investigates its impact on surface rainfall and atmospheric cooling rates. A 1D model is used to examine the impact of raindrop evaporation on the evolution of the initial raindrop size distribution (DSD), the resulting reflectivity (Z), and differential reflectivity (ZDR) and surface rain rates. Raindrop evaporation leads to a decrease of Z and an increase of ZDR toward the surface because of the depletion of small raindrops that evaporate first and thus enhance the mean raindrop size. The latter effect, however, can be reduced because of the increasing temperature toward the surface and may even lead to a decrease of ZDR toward the surface. Two events with significant rain evaporation, observed simultaneously by a polarimetric X-band radar and a K-band Micro Rain Radar (MRR), offer quite detailed insight into the evaporation process. During the first event, which exhibits an initial ZDR > 1.5 dB in the upper rain column, raindrops undergo relatively weak evaporation as deduced from the decrease of the small raindrop fraction observed by the MRR. The second event is characterized by a lower initial ZDR < 0.5 dB with all raindrops evaporating before reaching the ground. A retrieval scheme for estimating the evaporation-related cooling rate and surface precipitation from polarimetric radar observations below the bright band is derived based on MRR observations. The algorithm is then used to simulate polarimetric X-band radar observations, which might mitigate uncertainties in the surface rainfall retrievals due to evaporation at far distances from the radars and in the case of beam blocking.

Corresponding author address: Xinxin Xie, Meteorological Institute, University of Bonn, Auf dem Huegel 20, 53121 Bonn, Germany. E-mail: xxie@uni-bonn.de
Save