Transcript O. Nuissier, V. Ducrocq, P. Drobinski, Piero Lionello and the

HyMeX(*)
an experimental program dedicated to the
hydrological cycle in Mediterranean
Presented by Olivier Nuissier(1)
On behalf of Véronique Ducrocq(1), Philippe Drobinski(2), Piero Lionello(3) and the HyMeX ISSC
(1) GAME-CNRM, Météo-France & CNRS, Toulouse, France
(2) IPSL-LMD, CNRS, Palaiseau, France
(3) Department of Science of Materials, University of Lecce, Italy
http://www.hymex.org/
Email: [email protected]
*Hydrological cycle in the Mediterranean eXperiment
Motivations, societal stakes
The Mediterranean basin:
 A nearly enclosed sea surrounded by very urbanized littorals and
mountains from which numerous rivers originate
 A unique highly coupled system ( Ocean-Atmosphere-Continental surfaces)
 A region prone to high-impact events related to the water cycle:
 Heavy precipitation, flash-flooding during fall
 Severe cyclogeneses, strong winds, large swell during winters
 Droughts, heat waves, forest fires during summers
 Water resources: a critical issue
 Freshwater is rare and unevenly distributed in a situation of increasing water
demands and climate change (180 millions people face water scarcity)
 The Mediterranean is one of the two main Hot Spot regions of the
climate change
 Need to advance our knowledge on processes within each Earth
compartment, but also on processes at the interfaces and feedbacks in order
to progress in the predictability of high-impact weather events and their
evolution with global change.
Main Objectives
 to improve our understanding of the water cycle, with emphases on the
predictability and evolution of intense events
by monitoring and modelling:
the Mediterranean coupled system (atmosphere-land-ocean),
its variability (from the event scale, to the seasonal and interannual scales)
and characteristics over one decade in the context of global change
 to evaluate the societal and economical vulnerability to extreme events and the
adaptation capacity.
In order to make progress in:
 the observational and modelling systems, especially of coupled systems. This
requires new processes modelling, parameterization development, data assimilation
of new observation types for the different Earth compartments, reduction of
uncertainty in climate modelling.
The prediction capabilities of high-impact weather events,
 The accurate simulation of the long-term water cycle,
 The definition of adaptation measures, especially in the context of global change.
Major disciplines: Meteorology, Oceanography, Hydrology, Climatology, Societal sciences
Main Scientific Topics
Key questions:
What is the variability of the
components of the water cycle
(precipitation, evaporation, runoff, transport, etc) within a context
of global climate change ?
What are the impacts on the water
resources ?
Better understanding of the
long-term water cycle over
the Mediterranean basin:
variability and trend
Main Scientific Topics
Mesoscale convective systems
Slow-moving frontal systems
Coastal orographic precipitation
Better understanding of the intense events:
processes and contribution to the trend
Mediterranean cyclogeneses
Regional winds
(Mistral, Bora, Tramontana)
Key questions:
What are the ingredients and their
interactions necessary to produce an extreme
event ?
What will be the evolution of intense events
with the global climate change ?
Main Scientific Topics
Monitoring the
vulnerability factors
and adaptation
strategies facing highimpact weather events
Key questions:
How to reduce the impacts of the extreme
events and climate change ?
Observation strategy
 « Nested » approach necessary to tackle the whole range of processes and
interactions and estimate budgets
Enhanced existing observatories and
operational observing systems in the target
areas of high-impact events: budgets and
process studies
(+ dedicated short field campaigns)
Enhanced current operational observing
system over the whole Mediterranean
basin: budgets
(data access  ‘data policy’)
LOP
EOP
SOP
Special observing periods of high-impact events
in selected regions of the EOP target areas
(aircrafts, ships,…): process studies
?
First EOP/SOP series
--- Target Areas of the first EOP/SOP series
Hydrometeorological sites
Ocean sites
Key regions for dense water formation
and ocean convection
SOP1 in order to document:
- Heavy precipitation and Flash-flooding
- Ocean state prior the formation of dense water
EOP/SOP for the
NW Med. TA
Phasing with
T-NAWDEX
campaign field
SOP2 in order to document:
- Dense Water Formation and Ocean convection
- Cyclogenesis and local winds
2011
2012
2013
2014
Modelling Strategy
The HyMeX modelling strategy includes:
 The improvement of convective-scale deterministic forecast systems to improve the
prediction capabilities of Mediterranean high-impact weather events. HyMeX field campaigns
should provide an unique high-resolution database to validate these new NWP systems: microphysical properties
(polarimetric radars, aircraft measurements), marine boundary layer characteristics and air-sea fluxes
measurements (buoys, research vessels), novel high-resolution moisture measurements (GPS delays on board
ships, radar refractivity, water vapor from lidar, etc).
 Some versions of these systems will run in real-time during the SOPs to serve as guide for
the dedicated instrumentation. Other on-going studies based on NWP and modeling systems are carried
out to prepare the deployment of observation platforms (aircraft, vessels, sounding, lidars, etc)
The AROME-WMED
model is a research version
of the Météo-France
AROME NWP system
running its own 3-hourly
rapid update assimilation
cycle at 2.5 km.
 See also Doerenbecher et al’s Poster about balloons deployment during HyMeX
Modelling Strategy
The HyMeX modelling strategy includes:
 The design of high-resolution ensemble modelling systems dedicated to the study of the
predictability of Mediterranean heavy precipitation and severe cyclogenesis. Quantifying and
rating the different sources of uncertainty at various scales that impact the forecast of Mediterranean intense
events is one goal of HyMeX through the design of multiscale and nested ensemble forecast systems,
possibly based on mesoscale ensemble data assimilation techniques.
 The coupling of these ensemble forecast systems with hydrological models to issue
probabilistic forecast of the impact in terms of hydrological response. Advances in knowledge of
the hydrological and hydraulic responses as well as of the soil water content state before and during the
precipitation events should help to improve these hydrological models.
M0
M1
M2
M3
OP
(m3.s-1)
Simulated discharges
with ISBA-TOPMODEL
M0
M1
M2
M3
M4
M5
M6
M7
M4
M5
M6
M7
M8
M9
M10
24h- simulated
rainfall from AROME
model from 1 Nov.
2008 at 12 UTC
M8
M9
M10
OBS
RAD
 See also Nuissier et al’s Poster for example of such systems
Modelling Strategy
The HyMeX modelling strategy includes:
 The development of regional coupled systems (ocean-atmosphere, atmosphere-land,
ocean-land-atmosphere) and downscaling methods to reduce uncertainties of the future
climate regional projections for Mediterranean intense events.
 The development of new process modelling, parameterization development, novel data
assimilation systems for the different Earth compartments. For example, improvement of air-sea
flux parameterizations or development of data assimilation in cloud and precipitation systems are major
objectives of HyMeX and part of the observation strategy is designed to serve these objectives.
Example of Impact of the assimilation of radar reflectivity for an HPE
Observed radar rainfall
From Caumont et al, 2009
Rainfal forecast without
radar reflectivity assimilation
Rainfal forecast with
radar reflectivity assimilation
Thank you for your attention
for remarks and questions contact Véronique Ducrocq
[email protected]