Author(s): Roberta K. Mocva-Kurek, Miguel A. Rico-Ramirez, Adrián Pedrozo-Acuña
Keywords: Drop size distribution (DSD); Disdrometer data; Z-R relationship;Mexico City;
Abstract: Knowledge on drop size distribution (DSD) and their spatial-temporal variability is very important in hydrology, e.g. for radar quantitative precipitation estimation (QPE) and erosive process studies. DSD, being a central topic in radar meteorology, because it conducts a good conversion of radar reflectivity factor (Z) in rainfall (R). The disdrometers are used to measure the DSD at a given location and are useful in determining the shape of the DSD, it enables a better estimation of the coefficients of reflectivity-rainfall (Z-R) relationship that is used in precipitation measurement with weather radars. The lack of a specific Z-R relationship for the weather radars located in Mexico City and the presence of a dense network of 39 optical disdrometers (OTT Parsivel2) with 1 min resolution (namely OH-IIUNAM) motivates the present study. This paper presents the first evaluation of the spatial-temporal shape variability of the normalised gamma DSD within the city and the calibration of a Z-R relationship considering the DSD using data from 9 OH-IIUNAM disdrometers. The preliminary results show that the normalised gamma distribution can represent the DSD shape in Mexico City, as well as that DSD and Z-R relationship presents a spatial and temporal variability. In addition, highlighting the importance ofdetermining a local Z-R equation.