This page no longer exists
due to awfull Numericable services...
you can visit my alternative Google Web site:
The Google-site is HERE
Research activities.
My research activities concern the possible improvements in
the understanding of the Energetics of the moist atmosphere
which is assumed to be a mixing of dry air
species (O2, N2, Ar, CO2, H2, ...) and the
water components (H2O vapour, liquid, solid).
The thermodynamics of the moist atmosphere is often understood
as the study of changes in energy, or exchanges between
the different forms of energy.
However, the three laws of thermodynamics concern the definition
and the computations of both energy and entropy.
Accordingly, the processes of production or destruction in
entropy by atmospheric processes are to be studied at the
same time as the changes in energy.
Changes in energy and entropy may occur, for instance,
when the moist air is heated or cooled by the radiation
processes, or when the parcels of the atmospheric moist air
are rearranged by turbulent or convective processes, or
when latent heats of vaporization or fusion are delivered
or absorbed.
The first important contribution of E.N. Lorenz
to the atmospheric science is not his famous 1963 paper
dealing with the sensitivity of dynamical system
to initial conditions, and leading to the Butterfly
effect and the modern theory of Chaos...
The first important paper of Lorenz is a
previous one published in 1955,
where he has defined the
concept of Available Potential Energy (APE),
by generalizing the older approach of Max
Margules (1903) and with the entropy involved
in terms of rearrangement of the mass
with equal values of the potential temperature,
a meteorological way to measure the entropy.
In fact, it is possible to follow another approach
to study the Energetics of the moist atmosphere,
by following the founders of Thermodynamics like
Carnot (1823), Kelvin (1853, 1879), Maxwell (1871),
Gibbs (1873), Gouy (1889), Stodola (1898), among
others... (PDF copies of most of these old
contributions are available in this Web site)
The old concepts of "Motive Power of Heat",
"Motivity"
"Available Energy" or "Available Enthalpy"
corresponds to the same concept of
"Availability of energy", a concept which is nowadays
called Exergy in most of Thermodynamic
books, according to the word coined by Rant
(1956) in general Thermodynamics and retained
in Bejan's book (1987).
I have worked since 1988 to determine
if the concept of "flowing Exergy" or
"available enthalpy"
might be used in place of the APE of Lorenz
(Marquet 1990, 91, 93, 95, 2003).
It is found that the Available Enthalpy
local function depends on a function of
the temperature which possesses a quadratic
approximation.
In that, my research follows the previous atmospheric
approaches of Normand (1946), Dutton (1973),
Pearce (1978) or Karlsson (1990), among others.
The concept of "Pseudo-Activity"
can be put in relation with not only
the Margules-Lorenz
APE (see Shepherd, 1993), but also to the
Available Enthalpy function
(see Marquet, 1995),
with the pressure component of the
Available Enthalpy depending on a
quadratic function of pressure already
defined in the Margules 1901's
companion paper of the 1903's one
which had inspired Lorenz
(1955) works (still unpublished results).
The paper published in 2011 in the Quarterly journal of the meteorological Society (QJRMS) deals with the definition of the moist-air specific entropy of atmosphere.
It is shown that the properties of specific entropy of moist air (s) can be represented by a potential temperature denoted by θs, according to the relationship s = sref + cpd ln(θs), where sref and cpd are two true constant terms.
It is shown from observations that θs is almost constant within the whole planetary boundary layer (PBL) of marine stratocumulus, with almost no top-PBL jump in θs.
This result may confirm that the specific moist-air entropy is the key quantity which is well-mixed by the moist-air turbulent processes.
A paper published in 2013 in the QJRMS (Marquet and Geleyn) deals with the definition of the moist-air Brunt-Väisälä Frequency (BVF).
The moist-air specific entropy of atmosphere defined in Marquet (2011) is used as a starting point for the computations of the BVF, with compact results expressed for the two cases of non-saturated and saturated air.
The specific enthalpy of moist air is defined in a paper available in the Early view part of the QJRMS since March 2014.
Comparisons with the well-known Moist Static Energies (MSE) show that differences may be large enough to justify the use of the specific enthalpy of atmosphere expressed by h = href + cpd Th, where href and cpd are two true constant terms.
The moist-air potential vorticity (PVs) is defined in a paper published in April 2014 in the QJRMS.
The moist-air specific entropy of atmosphere defined in Marquet (2011) is used as a starting point for the computations of the PVs.
It is shown that the use of θs in the PV operator leads to smaller negative values of MPV than with the previous results obtained with the use of θ'w or θe.
This results may indicate that the specific moist-air entropy of atmosphere defined in Marquet (2011) may be a new, fruitful starting point for a renewal of moist-air Potential Vorticity analyses.
PDF's version
of lectures, seminars or conferences
are available in the internal pages
of the Web site,
including copies of my PhD and of
several of the papers.
Curiculum vitae.
I'm a research scientist at the CNRM
research centre of
Météo-France, Toulouse.
I work since May 2014 in the GMAP team
directed by A. Joly and F. Bouyssel.
The aim of GMAP is to develop the NWP
models of Météo-France
(ARPEGE, ALADIN, AROME).
I belong to the PROC subteam directed by
Y. Bouteloup. The aim of PROC is to develop
and improve the physical parameterizations.
I have worked in the Laboratory of Forecasting
during the period 2008-2014 (deputy director).
This team was directed by P. Santurette.
The intend of this team was to select or suggest recent
research products and to try to prepare operational versions of
them, in order to help the operational forecaters
by providing new operational tools.
I have worked in the Climate team of
the CNRM research centre during the period
1995-2008.
The Climate team was directed by S. Planton and
M. Déqué).
I have been in charge with the development of several
physical parameterizations in the ARPEGE-Climate
GCM (cycle 18 to 32). In particular, the prognostic
TKE equation and the bulk microphysic
Lopez schemes presently
used in the NWP version of ARPEGE have been first
tested and tuned in the GCM version of ARPEGE.
From 1995 to 2008
I have participated to MERCURE, EUROCS, GCSS, GPCI
and AMMA international programs and to several SCM
/ LES inter-comparisons (in particular for the
ARM-Cumulus and RICO-composite cases).
I have passed my PhD in 1994 at the
Paul Sabatier Univestity, Toulouse, France.
Title: "Application du concept d'Exergie à
l'énergétique de l'atmosphère.
Les notions d'enthalpies utilisables sèche
et humide." (in French). In English: "Applications
of the concept of Exergy to Atmospheric Energetics.
Dry and moist versions of the Available Enthalpy".
Prud'Homme
price award for the best 1993-94 thesis.
From 1990 to 1995, I have coded the mixed
explicit-implicit Normal mode initialisation
in the (new) ARPEGE-IFS NWP models (cycle 6
to 10). I have then been in charge with
operational control activities of the
ARPEGE NWP model.
From 1988 to 1990, I have followed a 2.5 years
stay at the Polytechnic School at Palaiseau,
France, in the Laboratory of Dynamical
Meteorological (LMD), as a post-graduate
of the French Meteorological school (promo
1986-88), during a period of formation to
research activities.
It is during this period that I have
rediscovered the Available Enthapy
and its potential interest in
Atmospheric science.
Second "Ingineer" degree of the School of Meteorology
(Toulouse, promo 1986-88).
Operational forecaster at Rennes (83-86).
Licence of Physics at the Universities of
Paris VII (1982) and Rennes (1985).
Military services (83-84).
First "Ingineer" degree of the School of Meteorology
(St Cyr, then Toulouse, promo 1980-83).
Preparatory schools (Math'Spe in Lycée
Chauteaubriand at Rennes 79-80 ;
Math'Sup in Lycée Rabelais
at St Brieuc 78-79).
Baccalaureate in 1978 (Lycée
de la Fontaine des eaux, Dinan, 1975-78).
Collège Roger Vercel, Dinan (1972-75).
Elementary School at Dinan (1969-72).
Elementary School at Tinténiac (until 1969).
Born at Combourg (April 1960).
