An efficient modular volume-scanning radar forward operator for NWP models: description and coupling to the COSMO model

Zeng, Yuefei; Blahak, Ulrich und Jerger, Dorit (2016): An efficient modular volume-scanning radar forward operator for NWP models: description and coupling to the COSMO model. In: Quarterly Journal of the Royal Meteorological Society, Bd. 142, Nr. 701: S. 3234-3256

Abstract

Since radar observations are highly dense in spatial and temporal resolutions, they have been often used to improve short-term numerical weather prediction (NWP) by means of detailed model verification and 3D radar data assimilation. However, the observed quantities are not directly comparable to the prognostic variables of NWP models (e.g. hydrometeor densities, wind vector, temperature, pressure, etc.), so a common approach to facilitate this comparison is to derive synthetic radar observations from model variables;this is the so-called radar forward operator'. In the present article, a new Efficient Modular VOlume scanning RADar Operator (EMVORADO) for Doppler velocity and reflectivity is introduced. Although it has been developed in the COSMO model framework, it can be also coupled online to any other NWP model. Comprehensive physical aspects of radar measurements (e.g. beam bending/broadening/shielding, Doppler velocity with fall speed and reflectivity weighting, attenuated reflectivity, detectable signal, etc.) have been implemented in a modular way, using state-of-the-art methods with different levels of approximation and numerical costs that can be optionally chosen. The reflectivity derivation from the prognostic model variables is as model consistent' as possible and carefully honours the uncertainties associated with partially melted particles. Efficiency and applicability on supercomputers (MPI-parallelism) is a major design criterion, which allows us to simulate entire networks of 3D volume-scanning meteorological radars within one model run and makes EMVORADO well suited for operational applications. This article aims to give a thorough description of the EMVORADO and to provide a first insight to the performance of different modules by some selected case-studies.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-9009
• Sprache: Englisch