Ann. Geophys., 27, 555-567, 2009
www.ann-geophys.net/27/555/2009/ doi:10.5194/angeo-27-555-2009 © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. |

04 Feb 2009

Cooperative Institute for Research in Environmental Sciences (CIRES), Univ. Colorado, Boulder, CO 80309-0216, USA

Earth System Research Laboratory (ESRL), NOAA, Boulder, CO 80305, USA

Abstract. Before radar estimates of the raindrop size distribution (DSD) can be assimilated into numerical weather prediction models, the DSD estimate must also include an uncertainty estimate. Ensemble statistics are based on using the same observations as inputs into several different models with the spread in the outputs providing an uncertainty estimate. In this study, Doppler velocity spectra from collocated vertically pointing profiling radars operating at 50 and 920 MHz were the input data for 42 different DSD retrieval models. The DSD retrieval models were perturbations of seven different DSD models (including exponential and gamma functions), two different inverse modeling methodologies (convolution or deconvolution), and three different cost functions (two spectral and one moment cost functions).

Two rain events near Darwin, Australia, were analyzed in this study producing 26 725 independent ensembles of mass-weighted mean raindrop diameter