HyMeX

http://www.hymex.org/

Email: hymex@cnrm.meteo.fr

Véronique Ducrocq, Philippe Drobinski

Chairs of HyMeX Executive Committee

CNRM-GAME, Toulouse, and IPSL

and coauthors

Motivations and Societal

Stakes

Need to advance our knowledge on processes related to water cycle within all

Earth compartments, to progress in the predictability of high-impact weather

events and their evolution with global change.

A nearly enclosed sea surrounded by very urbanized littorals and mountainsfrom which numerous rivers originate

A region prone to high-impact events related to water cycle:Heavy precipitation, flash-flooding during fall

Severe cyclogenesis, strong winds, large swell during winters

Droughts, heat waves, forest fires during summers

Water resources: a critical issueFreshwater is rare and unevenly distributed in a situation of increasing water demands and climate change (180 millions people face water scarcity)

The Mediterranean is a main Hot Spot region of the climate changeLarge decrease in mean precipitation, increase in precipitation variability during dry (warm) season, large increase in temperature (+1.5 à + 6 C in 2100)

A unique highly-coupled (Ocean-Atmosphere-Land) system

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 (2010-2020) in the context of global change

to evaluate the societal

and economical vulnerability

to extreme events and the

adaptation capacity.

HyMeX objectivesScience topics

The five science Topics

Water resources

monitoring

Regional

climate

scenario

Forecast and

early warning

Mediterranean extreme events Heavy precipitation, flash-flooding

Flash-flood in Greece (1 death)

25 oct. 2009

22 oct. 2009

Landslide and flooding in

Southeast-France and Sicily

Heavy precipitation and flash-

flooding in Southeast-France

20-21 oct. 2009

Seasonal distribution of lightning activity

ATDNET network, Defer et al, 2007

Spring Summer Fall Winter

Gard, 8-9 Sept. 2002: ~700l in 24h> 20 fatalities, damages: 1,2 billion €

Algiers, 10 Nov. 2001: ~260l in 24 h>700 fatalities, damages: 4 billion €

Mediterranean is a large complex terrain region particularly

prone to heavy precipitation events

Several € billion/year of

damages in Mediterranean

Mediterranean extreme events Heavy precipitation - Goals

Satellite cloud top temperature

15 June 2010 – 8 UTC

Mediterranean Sea is a key region for heavy precipitation formation, but almost void of

observations Var (SE France), 15 June 2010

25 fatalities

Damages: ~ € 600 millions

HyMeX will improve kowledge on local

processes (cloud-aerosol interaction,

moist flow interacting with complex terrain)

HyMeX will improve documentation of the upstream condtions over

the Sea

~ half of the humidity feeding the precipitating systems is extracted

from the Mediterranean Sea

Most of the initial development of the coastal precipitating systems

occured offshore

HyMex Goal:

To advance the predictability of heavy

precipitation (location, timing and amount of

heavy precipitation) – in order to improve

warning of these events – by quantifying and

reducing uncertainties in the high-resolution

numerical weather prediction systems (data

assimilation, cloud processes representation,…)

Mediterranean extreme events

Flash-flooding - Goals

Satellite cloud top temperature

15 June 2010 – 8 UTC

Var (SE France), 15 June 2010

25 fatalities,

Damages: ~ € 600 millions

Triggering of flash floods in catchments, which may remain dry throughout much of the year.

Mediterranean region is characterized by small to medium watersheds, with fast hydrological response

6h

10’

1d

1000 km210 km2 100000 km2

HyMex Goal:

To advance the simulation of hydrological and

hydraulic response to heavy precipitation by

taking account the specificities of the

Mediterranean continental surfaces (geology,

geomorphology, vegetation, land-use and

anthropogenetic structures) in order to reduce

the impacts of the flash-flood

Mediterranean extreme events Economic and societal vulnerability - Goals

Mediterranean flash-floods do not concern only mountain/valleys, but also in floodplains along the coast

that shows one of the most important urban

increases where population, assets and

economic activities get concentrated.

Human behavior facing flash-floods

is considered as the most relevant

factor to explain the still high level

of fatalities.

People’s mobility is a vulnerability

factor (more than 40% of the deaths

during flash-floods – active people

in their daily travels).

1881 2005

Evolution of the population in Languedoc-Roussillon (F)

In communities with a “flood-culture”, pre-event adaptations and adequate in-event responses minimize damages

HyMex Goal:

To evaluate vulnerability to intense events and

adaptation capacity in the context of global

change to provide support to policy

development and mitigation measures in

connection with stakeholders

Mediterranean extreme events Intense air-sea exchanges - Goals

Mediterranean is a large complex terrain region particularly prone to wind gusts

(regional winds, Mediterranean depression)

Gulf of Genoa depression

Impact on the marine ecosystems (nutriment vertical mixing)

Impact on the Mediterranean water budget

Impact on the Mediterranean Sea circulation

Impact on the

Atlantic water

HyMex Goal:

To advance the understanding

of the high interanual variability

of dense water formation

through improvement of regional

air-sea coupled models and

observations

to address the question of the

evolution of DWF with the

climate change

EOP: Enhanced existing observatories and

operational observing systems in the target

areas of high-impact events: budgets and

process studies

(+ dedicated short field campaigns)

LOP : Current operational observing

system and observatories over the whole

Mediterranean basin: budgets

(data access)

SOP: Special observing periods of high-impact

events in selected regions of the EOP target areas

(aircraft, R/V, balloons,…): process studies

A « Nested » approach to tackle the whole range of processes and interactions and to

estimate budgets

Observation Strategy

SOP1: Heavy precipitation and flash-flooding

SOP2: Intense air-sea exchanges (severe winds, dense water formation)

Observation Strategy The LOP covers the whole Mediterranean basin

Three Target Areas (TA) canditates to the first EOP/SOP series, with embedded

hydrometeorological and « upstream » atmospheric sites.

The HyMeX modelling strategy includes:

The improvement of convective-scale deterministic forecast systems to improve the

prediction capabilities of Mediterranean high-impact weather event. 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 vapour from lidar, etc).

The design of high-resolution ensemble modelling systems dedicated to the study of the

predictability of Mediterranean heavy precipitation and severe cyclogenesis, and their coupling

with hydrological models to issue probabilistic forecast of the impact in terms of

hydrological response. HyMex is proposed as a testbed for these ensemble systems

The set-up, validation and improvements of multi-components regional climate models dedicated to the Mediterranean area: ocean, atmosphere, land surface, hydrology in order to study interannual variability, past trends and future climate change

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.

HyMeX Implementation Plan Modeling strategy

Highlights of WWRP-related activities

Mesoscale modeling

Goal : Process understanding for improving the parameterizations of high-

resolution NWP systems Microphysical processes: Cloud-aerosol interaction (CCN, ICN), Cold-pool

formation, Hydrometeor retrievial methods and validation of the microphysical

parameterizations with in-situ and airbone microphysical observations

Turbulence, cloud and precipitation parameterisations (« grey zone »)

MCS du 20 octobre: réflectivité radar à 16 UTC

5. 10. 15. 20. 25. 30. 35. 40. 45. 50. 55. 60.

(dBz)

Observations 2.5 km run 0.5 km run

1D Turb. 3D Turb.

reflectivity

Air-sea flux interactions: ocean-atmosphere coupled models to study the interaction

and their importance to take them into account for short-range high-resolution NWP

Highlights of WWRP-related activities

Ensemble prediction

THORPEX/TIGGE LAM:

TIGGE LAM has proposed at the 4th HyMeX Workshop to use the HyMEX

SOPs as a test-bed for evaluating the LAM EPS performances and to have a

collective contribution to answer scientific questions (mainly with WG3)

example of activities that should be conducted in synergy between programs:

quantification of the additional benefits of multimodel LAM EPS with parameterized

convection, sharing methodologies and use of same data standards (e.g. GRIB2,

output parameter list).

Convection permitting ensemble prediction systems with explicit convection

and horizontal resolution of a few kilometers:

Design, implementation and validation of, employed for short range predictions, is

an important objectives of HyMeX

Coupling of these atmospheric ensemble systems with hydrological models to issue

hydrological ensemble predictions is an other important objectives

HyMeX SOP1 2012 serves as a testbed for these new EPS

Highlights of WWRP-related activities

Ensemble predictionStreamflow simulated by the hydrological model ISBA-TOPMODEL for a flash-flood case over

Southern France watersheds

The model is driven by hourly precipitation forecast

from an ensemble simulation based on the AROME

model (resolution:2.5 km)

- Global ARPEGE EPS used as LBC combined with

ensemble data assimilation - Vié et al (2010)

The model is driven by hourly precipitation fields

derived from the AROME NWP operational suite

- A object-oriented perturbation method is applied to

the determinist QPF – Vincendon et al (2011)

ensemble spread between q 0.25 and q 0.75

ensemble median

AROME determinist run

ensemble members

observations

Streamflow simulated using:Legend:

Highlights of WWRP-related activities

Mesoscale data assimilation

Goals : Preparation of the real-time

operating mesoscale models

over the Mediterranean during

the field campaigns

Incl. Real Time assimilation of

EOP-SOP specific observation

Datasets (Drifting balloons,…)

Improvements in satellite radiance assimilation :

– Mesoscale observation operator (Duffourg et al 2010),

– Over the Sea, Enhanced density (correlations in observation errors),

– Over land, surface emissivity parametrisation and retrieval of skin Temperature

for hyperspectral sounders

–In cloudy conditions, use of model cloud variables for the brightness temperature

simulation

More European radar data assimilated in AROME WMED (work on radar data

format for assimilation purposes)

AROME-WMED

Highlights of WWRP-related activities

Mesoscale data assimilation

Assimilation of new observational data types, in particular those directly related to

precipitation:

– Water vapour lidar (Bielli et al, 2011)

– Moisture related data from wind profilers

– Radar refractivity and polarimetric parameters from weather radar,

– Dual polarization radar data

– Ground based radiometric data

Background error modelling

– Comparison of background error

statistics (AROME, WRF…)

– Heterogeneous background error covariances (rainy/non-rainy areas):

comparison, modelling (Montmerle and Berre, 2010)

– Dataset to study background error statistics for hydrometeors (Michel et al 2011)

Highlights ofn WWRP/WCRP-related

activities

Regional climate modeling HyMeX regional climate modeling activities:

contribute to the MED-CORDEX initiative included in the WCRP/CORDEX

program, which aims to improve the coordination of international efforts on

regional climate downscaling.

MED-CORDEX will make use of both regional atmospheric climate models

and regional coupled systems. Strong air-sea interactions take place in the

Mediterranean basin, motivating the use of coupled regional models.

Two main phases have been envisaged within the MED-CORDEX action:

– performing state-of-the-art coupled runs feeding the next IPCC report

(AR5) by mid 2011;

– developing new experiments to test new components and improved

schemes, based on the HyMeX field campaign outcomes and process-

oriented diagnostics (e.g. water budget of the Mediterranean Sea)

International Partnership

CNRS/INSU

Météo-France

CNES

INRA, BRGM

CEMAGREF

IGN,IFSTTAR

CNR

CINFAI

ENEA

OGS

INGV

ARPA

CIMA

KIT, DLR, PIK

Univ. Hohenheim

Univ. Wageningen

TU Delft,KNMI

AEMET, IMEDEA

Meteocat,UCLM,ICM

Univ. Barcelona,

Balearic islands

EUMETNET/EUCOS

NOA

HCMR

Univ.

Athens

IMS

Univ.

Jerusalem,

Tel Aviv

MHS, Univ. Zadar

MHS

IMS

Univ. Vienna, ZAMG

EPFL, ETH

HyMeX is endorsed by the Joint Scientific

Committee of the World Weather Research

Program (WWRP) and the WWRP/THORPEX

program (high-impact weather events)

HyMeX is a a Regional Hydroclimate

Project (RHP) of the World Climate Research

Program WCRP/GHP (GEWEX

Hydroclimatology Projects)

NOC

Univ. Bristol

DMN

Univ. RabatINSTM

NOAA

NRL

NASA

NCAR

Univ.

Connecticut,

Colorado

McGill

Env. Canada

Univ. Auckland

ONM,CRAAG,INCT

COC

CIESM

HyMeX organizationMain Phases and documents

Phase 1

White BookInternational Science Plan

(ISP)

Phase 22006 2008

International Implementation Plan (IIP)

International HyMeX

Workshops

17-19 May 2011

5th HyMeX Workshop

LOP

Sept. 2010

EOP

SOP

HyMeX OperationsHyMeX Preparation

Phase A

Minorca