| dc.description.abstract | To monitor extreme precipitation, the operational radar network in Taiwan will be set up with dual-polarimetric radars at S and C-band. It should be noted that each polarimetric parameter of different wavelength radars for quantitative precipitation estimation (QPE) has unique advantages and disadvantages. Thus, the goal of this study is to discuss and analyze QPE products of each radar as a base for merging rain maps.
Four different QPE relationships of each rain types, namely R-Z,R-KDP, R-(Z,ZDR) and R-(KDP,ZDR), are obtained from over-six-year NCU 2D-Video disdrometer data and applied to nine events observed by both RCWF S-band and NCU C-Pol radars from March of 2014 to August of 2015. The performances of radar-based QPE are investigated by comparing with 96 rain gauges.
Without considering radar measurement error, in the rain-type coefficients test by simulated radar parameters, it shows that most of algorithms improve after applied into the corresponding coefficients with respect to general coefficients, and R-(Z,ZDR) algorithm has the most significant improvement. In the radar data quality control process, the wet radome effect correction of Z has a positive impact on RCWF as well as NCU C-Pol radar. Overall,KDP-based relationships which combine with R-Z are the most accurate. In the comparable sampling frequency test, NCU C-Pol radar shows the advantage of KDP parameter for QPE at shorter wavelength with lower RRMSE and higher correlation coefficient. Besides, the factors resulting in QPE errors of each algorithm will be discussed, such as measurement error, wet radome effect and DSD variability with height. In the last part, the result indicates that when two radars’ data are included whenever available, the QPE performance can be further improved. | en_US |