Applications are invited for a Visiting scientist Activity to be funded by the H-SAF Consortium.
Research Fields: Precipitation, Microwave, radar, validation, Scientific computing and data processing
HSAF Science Coordinator
Maj. Davide MELFI
Italian Air Force Meteorological Service
Centro Operativo per la Meteorologia
Beneficiaries: Department of Civil Protection (DPC) - Rome
Benefits and salary
The financial contribution to a VSA can only consist of, cost reimbursement on a per diem basis (VS), contribution to salary costs (AS) and travel cost reimbursement. Other costs e.g. hardware, equipment, third party services, cannot be charged to the VS programme.
The total cost of the activity will depend by the work plan proposed by the attender (see below) and it can’t exceed 11914 Euros.
Only experts/scientists from entities (NMSs or other public Institutions e.g. Universities or Research Centres) not involved in the concerned SAF cooperating entities’ organization or their controlled sub-entities can be selected as VS.
We are seeking a candidate with a PhD, or at least 4 years of working experience after the Master's completion, in Atmospheric Science or related physical science or engineer discipline, with a good background in dual-polarization radar algorithm development.
The best candidate will also be proficient in scientific programming languages (e.g., Python, MATLAB, Perl, etc.), UNIX/Linux scripting language, and scientific graphical software packages (e.g. GrADS, MATLAB, etc.).
She/He must have good-quality written and oral communication skills in the English language.
Evidence of published research in these areas will be a plus.
Conditions of international mobility of researchers: Researchers are required to undertake transnational mobility (i.e. move from one country to another) when taking up the appointment.
Description of the motivation and expected objective of the proposal are described below
Applications must include:
- Defining of “tasks and methods “ in the proposal
- copy of valid identity documents
Applications has to be completed by 28 February 2017, although the search will continue until the positions is filled.
Quantitative precipitation estimation requires accurate evaluation of the main error sources, including calibration, ground clutter, anomalous propagation, beam blockage, W-LAN interferences, and rain path attenuation (e.g., Bringi and Chandrasekar 2001).
Dual-polarization technology has greatly improved the quality of radar precipitation measurements and reduced the gap between the qualitative and quantitative use of radar observations.
Several operational S- and C-band radar networks have been upgraded to adopt dual-polarization technology. In the past decade, many studies have been undertaken to explore the benefit of polarimetry for quantitative precipitation estimation (QPE) using X-band radars (Anagnostou et al., 2004; Matrosov et al., 2005; Wang and Chandrasekar, 2010; Matrosov et al., 2013, Koffi et al., 2014; Vulpiani et al., 2015), which are de facto very appealing systems due to their compact size, transportability and, generally, affordable cost.
However, attenuation remains the major impairment for the quantitative use of X-band radar systems, despite the availability of robust correction methods and rainfall algorithms based on a specific differential phase that is immune to attenuation.
In the presence of heavy rain and hail mixtures, partial attenuation can be further enhanced, leading to signal extinction (Tabary et al., 2009).
Furthermore, Drop Size Distribution (DSD) variability also plays a relevant role in the determining the uncertainty related to rainfall retrieval process.
In addition to the radar reflectivity factor, the use of differential reflectivity (ZDR) and specific differential phase (KDP) can potentially reduce the DSD dependency of the radar rainfall algorithms.
Notwithstanding, ZDR can be heavily affected by miscalibration, rain path attenuation, wet-radome attenuation, interferences. KDP is immune to radar calibration and partial beam blockage but is not directly measured. It has to be derived by the Differential Phase FDP that is affected by measurements noise, back scattering effects, and system offset (Bringi and Chandrasekar, 2001).
For these reasons, the present VS activity is devoted to critically evaluate the algorithms framework currently implemented within the manufacturer software package with the aim to optimize in the light of the recent advancement in the field.
A special focus will be devoted to the optimal processing of FDP in order to correct for attenuation, on one side, and estimate precipitation, on the other side.