Post-doctoral Research Fellowship in RADARMETEOROLOGY
Place: Centre de Météorologie Radar, Direction des Systèmes d’Observation,
Météo France, 7, rue Teisserenc-de-Bort 78195 Trappes France. Trappes
is located 20 km to the west of Paris. The Météo France site is connected
to Paris downtown (Gare Montparnasse and La Defense) by train (30 minutes).
Temporary lodging at the Météo France site is possible. The selected
candidate will be located in Trappes but he / she will have to participate
in an approx. 2-month training in Toulouse to become familiar with the
French non-hydrostatic AROME model and its outputs.
Application deadline : 31 October 2005
Duration / Start : 18 months, starting approx. January - March 2006
Context
The "Centre de Météorologie Radar" of Météo France is in charge of the
development and maintenance of the 24 radars of the French radar network.
The development team consists of about 15 people that work on new algorithms
and products. One of the operational C-band radar of the network (Trappes,
20 km west of Paris) has been recently equipped with polarization diversity
(simultaneous H and V transmission) and much effort has been dedicated
to the evaluation of this new technology for hydrological and microphysical
applications (see the bibliography below).
The "Centre de Météorologie Radar" is involved in the FLYSAFE European
project (6th Framework Programme of the European Commission), which
aims – for the meteorological part - at developing new tools and systems
that monitor and forecast atmospheric hazards such as convection, icing,
clear-air turbulence, wake vortex, … in order to increase the safety
of flights for all aircrafts. A real-time demonstration phase is planned
in 2008 in the Paris area (Orly and Charles-de-Gaulle airports), which
is very densely covered with operational and research observational
means.
The operational Trappes C-band polarimetric radar is the core of the
Paris area instrumental set-up and the main task during the development
period (2006 – 2007) is thus to develop and validate robust and efficient
methods to retrieve 1) the 3D wind structure and 2) the dominant particle-type
at a high space-time resolution (5 minutes x 1 km² x 200 m) over a mesoscale
domain (300x300 km²) centred on the Paris airports.
Work description
The candidate will be involved in the refinement and validation of the
current particle-type identifier (Gourley et al. 2005a,b,c) that relies
on a fuzzy logic approach. Procedures to correct radar data for attenuation
(Z and ZDR), calibration biases (on Z and ZDR), bias due to low SNR
(on HV, Z and ZDR) and noise on DP have already been
developed and tested. The membership functions have been built empirically
with a Gaussian kernel approach from a large set of situations. Special
emphasis will be laid on the diagnostic of hail and supercooled water
and on the discrimination between rain and snow. Ultra-short-term forecasts
from the French new-generation mesoscale model AROME (Ducrocq et al.
2005) will be used to refine and constrain the particle-type retrieval
following the approach initiated by Scharfenberg et al. (2004). Indeed,
realistic temperature, humidity, KTE (kinetic Turbulent Energy) and
hydrometeor fields are needed to correctly interpret polarimetric radar
data. Validation of the results of the algorithm will be performed by
using data from the SIRTA (Site Instrumental de Recherches en Télédétection
de l’Atmosphère, http://sirta.lmd.polytechnique.fr).
The SIRTA is a joint effort of several French research laboratories
(CETP, SA, LMD, …) to concentrate various remote-sensing instruments
in order to better understand the physics of clouds and aerosols. The
site is located about 20 km from Trappes. The instrumental set-up includes
a C-band polarimetric radar (Ronsard), radiometers, lidars, cloud radar,
automatic stations, … Altogether, more than 30 researchers (cloud physicists,
modellers, ..) are involved in the activities of SIRTA.
References
Ducrocq, V., F. Bouttier, S. Malardel, T. Montmerle, and Y. Seity, 2005:
The AROME Project, La Houille Blanche, no2, 2005.
Gourley, JJ, P. Tabary, J. Parent-du-Chatelet, 2005a: assessing the
quality of the French C-band polarimetric radars, submitted to J. Atmos.
Oceanic Technol.
Gourley, JJ, P. Tabary, J. Parent-du-Chatelet, 2005b: empirical estimation
of attenuation from total differential phase, submitted to J. Atmos.
Oceanic Technol.
Gourley, JJ, P. Tabary, J. Parent-du-Chatelet, 2005c: particle-type
identification with an operational polarimetric C-band radar, submitted
to J. Atmos. Oceanic Technol.
Scharfenberg, K.A., and K. Lakshmanan, 2004: The use of NWP data in
polarimetric hydrometeor classification, 11thConference on Aviation,
Range and Aerospace Meteor. Hyannis, MA, Amer. Meteor. Soc.
Required qualification
Applicants should have a Ph.D. in Environment, Atmospheric Sciences
or Remote Sensing. A good knowledge of radars, radar data and their
interpretation is required. Knowledge of polarimetric radars and related
algorithms would definitely be an advantage. Applicants should be fluent
in oral and written English or French. Knowledge of UNIX / LINUX is
required (FORTRAN, C, C++) and experience with IDL or PV-WAVE highly
recommended. The work will be supervised by Dr. Pierre Tabary (Météo
France, Trappes, France), Dr. Georges Scialom (CETP, Vélizy, France)
and Dr. François Bouttier (Météo France, Trappes, France). Salary will
be approximately 2300 Euros net per calendar month, before income tax,
according to job experience. The selected candidate will be located
in Trappes but he / she will have to participate in a approx. 1 – 2
month training in the group of Dr. François Bouttier in Toulouse to
become familiar with the AROME model and its outputs. This job is
offered with no restriction on age, sex nor nationality, in accordance
with French law. Applicants should send a letter of interest, a curriculum
vitae (resume + list of publications), date of availability and names,
fax numbers, e-mail and post addresses of two references by 31 October
2005 to:
Dr. Pierre Tabary
Centre de Météorologie Radar, Direction des Systèmes d’Observation
Météo France, 7, rue Teisserenc-de-Bort, 78195 Trappes FRANCE
Tel : (+33) 1 30 13 61 46
Fax : (+33) 1 30 13 60 62
Email : pierre.tabary@meteo.fr
AND
Dr. François Bouttier
Météo-France CNRM/GMAP
42 Av Coriolis
31057 Toulouse cedex 01 France
e-mail: francois.bouttier@meteo.fr
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