Comparison of Disdrometer and Rain Gauge Measurements during pre-CHUVA* Ali Tokay1,2, Paul G. Bashor3,4, David B. Wolff5,2, Walter A. Petersen6, and Matthew Schwaller2 1JCET - University of Maryland Baltimore County 2NASA Goddard Space Flight Center 3Computer Sciences Cooperation 4NASA Wallops Flight Facility 5Science Systems Applications Inc. 6NASA Marshall Space Flight Center *Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the globAl precipitation measurement Field Campaign period: March 1-26, 2010 Pre-CHUVA Data Acquisition Network -01.5 X-band polarimetric radar Disdrometer&Gauge site (INPE) Atlantic Disdrometer&Gauge site (Airport) -02.0 Ocean Maranhao Admirari State Anemometer tower Alcantara Sao Luiz International Airport 25 km University of Maranhao -02.5 50 km Sao Luiz 75 km (radar-airport) = 5.8 km 100 km (radar-INPE) = 2.0 km (radar-Admirari) = 7.7 km -03.0 (airport-INPE) = 4.3 km (airport-Admirari) = 2.4 km (INPE-Admirari) = 5.9 km -03.5 -45.5 -45.0 -44.5 -44.0 -43.5 Longitude (degree) pre-CHUVA Disdrometer & Rain Gauge Sites Parsivel disdrometer TB Rain gauges Joss-Waldvogel disdrometer Airport Site INPE Site Comparison of Rain Accumulation Comparison of Rain Accumulation Comparison of Rain Accumulation Comparison of Raindrop Size Distribution (event) Comparison of Raindrop Size Distribution (event) Comparison of Raindrop Size Distribution (event) Comparison of Raindrop Size Distribution (event) Comparison of Raindrop Size Distribution (instrument) Comparison of Raindrop Size Distribution (microphysics) OTT Parsivel Fall Velocity Measurements Parameterization of Raindrop Size Distribution * D m D N(D) NTf(m)( ) exp[(4 m) ] Dmass Dmass (4 m )m1 f(m ) * NT where NT (m 1) Dmass D m D N(D) Nwg(m)( ) exp[(4 m) ] Dmass Dmass 4m 256W 6(4 m) N where g(m) w 4 256(m 4) wDmass Comparison of Raindrop Size Distribution Parameters Gamma model parameters 03/20/10 03/21-22/10 03/24/10 03/24/10 * Normalized intercept (NT ) 113 155 77 134 Normalized intercept (Nw) 1486 2825 1090 1495 Mean mass Diameter (Dmass) 2.03 1.64 2.01 1.87 Shape parameter (m) 2.4, 1.7 4.2, 2.8 2.7, 2.8 1.8, 2.1 Gamma model parameters 03/20/10 03/21-22/10 03/24/10 03/24/10 * Normalized intercept (NT ) 106 135 68 82 Normalized intercept (Nw) 989 2151 447 1109 Mean mass Diameter (Dmass) 2.45 1.83 2.85 2.44 Shape parameter (m) 1.2, 0.4 3.3, 1.6 0.6, -0.6 2.5, 1.9 Comparison of Integral Rain Parameters Integral rain parameters 03/20/10 03/21-22/10 03/24/10 03/24/10 Concentration (NT ) 231 255 155 250 Liquid Water Content (W) 0.314 0.253 0.219 0.225 Rain Rate (RR) 7.0 5.0 4.9 4.8 Reflectivity (Z) 39 35 37 36 Integral rain parameters 03/20/10 03/21-22/10 03/24/10 03/24/10 Concentration (NT ) 262 248 196 201 Liquid Water Content (W) 0.438 0.300 0.366 0.483 Rain Rate (RR) 10.6 6.3 9.3 11.9 Reflectivity (Z) 43 37 45 43 Comparison of Raindrop Size Distribution Parameters 200 1.0 0.5 100 0.0 0 -0.5 -100 -1.0 -200 -1.5 1355 specta 1355 specta -300 -2.0 -1 0 1 2 -1 0 1 2 10 10 10 10 10 10 10 10 Joss-Waldvogel Rain Rate (mm) Joss-Waldvogel Rain Rate (mm) Comparison of Integral Rain Parameters 10 10 5 5 0 0 -5 -5 -10 -10 -15 -15 1355 specta 1355 specta -20 -20 -1 0 1 2 -1 0 1 2 10 10 10 10 10 10 10 10 Joss-Waldvogel Rain Rate (mm) Joss-Waldvogel Rain Rate (mm) Probability and Cumulative Distributions of Raindrop Size Distribution Parameters 0.10 1.0 0.10 1.0 pd (JW) cd (JW) pd (Parsivel) cd (Parsivel) 0.08 0.8 0.08 0.8 0.06 0.6 0.06 0.6 0.04 0.4 0.04 0.4 0.02 0.2 0.02 0.2 0.00 0.0 0.00 0.0 1 2 3 0 1 2 3 4 10 10 10 Mass_weighted_diameter (D , mm) -3 mass Concentration (NT, m ) Probability and Cumulative Distributions of Integral Rain Parameters 0.10 1.0 0.10 1.0 pd (JW) cd (JW) pd (Parsivel) cd (Parsivel) 0.08 0.8 0.08 0.8 0.06 0.6 0.06 0.6 0.04 0.4 0.04 0.4 0.02 0.2 0.02 0.2 0.00 0.0 0.00 0.0 -1 0 1 2 0 2 4 6 10 10 10 10 10 10 10 10 6 -3 Rain rate (RR, mm hr-1) Reflectivity (Z, mm mm ).