Why the African Initiative needs a Why the African Initiative needs a research component … and a research component … and a

suggested frameworksuggested framework

Mitch MoncrieffMitch MoncrieffCloud Systems GroupCloud Systems Group

NCAR/MMMNCAR/MMM

African Initiative Workshop, NCAR, July 6-7 2006

IntroductionIntroduction

• During past decades China, and more recently During past decades China, and more recently India, benefited immensely from scientific India, benefited immensely from scientific collaboration with the developed nations in collaboration with the developed nations in weather-climate researchweather-climate research, especially numerical , especially numerical modeling & field experiment activities modeling & field experiment activities

• Africa has yet to benefit to a comparable degree Africa has yet to benefit to a comparable degree

• There is a framework for a research component There is a framework for a research component for the African Initiative based on the following: for the African Initiative based on the following: a) NCAR’s research and modeling infrastructure; a) NCAR’s research and modeling infrastructure; b) the international AMMA programb) the international AMMA program

• One of Earth’s 3 major convective heat sources, One of Earth’s 3 major convective heat sources, Africa as an integral part of Earth’s Africa as an integral part of Earth’s climate climate

• Africa’s precipitation regimes are important in the Africa’s precipitation regimes are important in the weatherweather context context

• African monsoon is a unique example of African monsoon is a unique example of inter-annual inter-annual variability of climatevariability of climate

Why are convective systems over the U.S. Why are convective systems over the U.S. continent and West Africa similar ? continent and West Africa similar ?

Laing and Fritsch (1997)Laing and Fritsch (1997)

… … fundamental role of mesoscale fundamental role of mesoscale convective systems convective systems

(Moncrieff & Liu 2006)(Moncrieff & Liu 2006)

Ingredients of the dynamical similarityIngredients of the dynamical similarity

• Scale-interaction between convective systems and tropical Scale-interaction between convective systems and tropical easterly waves (c.f., synoptic waves over US)easterly waves (c.f., synoptic waves over US)

• Genesis of convective systems in Ethiopian Highlands (c.f., Genesis of convective systems in Ethiopian Highlands (c.f., Continental Divide)Continental Divide)

• Propagating systems in the Tropical Easterly Jet, African Propagating systems in the Tropical Easterly Jet, African Easterly Jet (c.f., westerly shear over US)Easterly Jet (c.f., westerly shear over US)

• Diurnal-cycle convoluted with propagating cloud-systems Diurnal-cycle convoluted with propagating cloud-systems

• Representing mesoscale convective organization in Representing mesoscale convective organization in parameterizations for climate models & global NWP models parameterizations for climate models & global NWP models

… … i.e, Research results for US translate directly to Africai.e, Research results for US translate directly to Africa

SSolar-heated elevated terrain, convective olar-heated elevated terrain, convective organization, propagation and shear … organization, propagation and shear …

-1c 17 ms

Initiation Initiation over mountainsover mountains

Far-field Far-field propagationpropagation

Cumulo-Cumulo-nimbusnimbus

Systems travel for 1000’s kmSystems travel for 1000’s km

Elevated solar heating Elevated solar heating determines start position & start determines start position & start time of traveling convectiontime of traveling convection

Mesoscale Mesoscale downdraftdowndraft

MCS: a MCS: a familyfamily of of cumulonimbuscumulonimbus

Shear: a key organizing effect Shear: a key organizing effect

Summertime convection over the continental US Summertime convection over the continental US simulated (MM5) and compared to radar simulated (MM5) and compared to radar observationsobservations

Summertime convection over the continental US Summertime convection over the continental US simulated (MM5) and compared to radar simulated (MM5) and compared to radar observationsobservations

Simulated precipitation from traveling convective Simulated precipitation from traveling convective systems systems Simulated precipitation from traveling convective Simulated precipitation from traveling convective systems systems

Cloud-system resolving model

(CSRM) NEXRAD analysis

(Carbone et al. 2002)10-km: Betts-Miller parameterization

10-km explicit : no convective param.

C

Mesoscsale Mesoscsale downdraft downdraft

U(z) - c

0z

*c = U (z )

latent heating

evaporative

cooling p

0

2 ( )z

z

FG dz

Numerical Numerical simulationsimulation

Dynamical Dynamical model model

++ = =

LL

Parameterized Parameterized convective convective

heating heating

Mesoscale Mesoscale heating & heating &

momentum momentum transport transport

Mesoscale downdraft Mesoscale downdraft coolingcooling

Stratiform Stratiform heatingheating

Dynamic Dynamic triggeringtriggering

Upscale evolution of convective organization Upscale evolution of convective organization

New hybrid parameterization New hybrid parameterization of convective organizationof convective organization

Stage 1: onsetStage 1: onset Stage 2: multicell families Stage 2: multicell families

Stage 3: mesoscale circulationStage 3: mesoscale circulation

nnnn

n + 1n + 1

nnn + 1n + 1

n + 2 n + 2 ……

p

African Monsoon Multidisciplinary African Monsoon Multidisciplinary Analysis (AMMA) is a comprehensive Analysis (AMMA) is a comprehensive international frameworkinternational framework

Full description: see presentation by Prof. Chris ThorncroftFull description: see presentation by Prof. Chris Thorncroft(SUNY/Albany): co-chair, International (SUNY/Albany): co-chair, International

Steering Committee for AMMASteering Committee for AMMA

\\

African Monsoon Multidisciplinary Analyses

Afrikanske Monsun: Multidisiplinære Analyser

Afrikaanse Moesson Multidisciplinaire Analyse

Analisi Multidisciplinare per il Monsone Africano

Afrikanischer Monsun: Multidisziplinäre Analysen Analisis Multidiciplinar de los Monzones Africanos

Analyses Multidisciplinaires de la Mousson Africaine

Objectives of AMMA International

• To improve our understanding of the West African Monsoon (WAM) and its influence on the physical, chemical & biological environment regionally and globally.

• To provide the underpinning science that relates variability of the WAM to issues of health, water resources, food security & demography for West African nations and defining and implementing relevant monitoring & prediction strategies.

• To ensure that the multidisciplinary research carried out in AMMA is effectively integrated with prediction & decision making activity.

Global SSTTeleconnections

Mesoscale Convective Systems

Convective Cells

Monsoon System

Easterly waves

GG SST Variability

Global

Mesoscale

Regional

Local

YearSeasonDayHour

Major River Basins

Catchments

Vegetation

Pools Vegetation

104 km

103km

102km

101km

SOP EOP LOP

SATELLITES

OBSERVATIONS

MODELLING / FORECASTS

A multiscale approach

Downscaling for impact studies

Scale Interactions

Water vapor transport Trace gas , aerosols, etc

Simulation and Simulation and dynamical modelingdynamical modeling

fits herefits here

1. AMMA International

To reach AMMA aims, need to coordinate -Science (Challenge: disciplines, scales) -Implementation (Obs, Model,..) -Data archive and sharing -Funding issues

ACMAD

AGRYMET

African Univ

ASECNA

CERMES

DMN, DHN, , EIER, others ...

Others inEuropeINTEO, ...

FranceCATCH

White BookAMMA-API

UKNERC

DABEX DODO

GermanyIMPETUS VOLTA

USAARM-DOE NOAA NASA

Pan

-afr

ican

init

iati

ve(P

IAF

)EU Integrated Project

ISSCISSC

Links with International Programmes (WCRP, IGBP, THORPEX, ..)

ST4ST4 Capacity Capacity building building

and and trainingtraining

WG1WG1

WG2WG2

WG3WG3

WG4WG4

WG5WG5

WAM & global climate (including aerosol/chemistry)

Water cycle

Land surface-atmosphere- ocean feedbacks

Prediction of climate impacts

Prediction of high-impact weather

Integrative ScienceIntegrative Science

TT1TT1Radio soundingsRadio soundings

TT2aTT2aSurface LayerSurface Layer

TT3TT3Gourma siteGourma site

TT4TT4Niamey siteNiamey site

TT5TT5Ouémé siteOuémé site

TT6TT6Oceaic campaignsOceaic campaigns

TT7TT7SOP-Dry seasonSOP-Dry season

TT8TT8SOP-Monsoon seasonSOP-Monsoon season

TT9TT9SOP-DownstreamSOP-Downstream

ST2 incl

AO

C

ST3 D

atabase

ST1 E

OP

/LO

P

Obs implementationObs implementation

ICIGICIG

TT2bTT2bAerosol & Radiation Aerosol & Radiation

ARMARM

Variability in the WAM impacts the US

Flooding in New Orleans due to Katrina (courtesy NOAA)

Bonnie (05)

Charlie (05)

Frances (05)

Ivan (05)

Courtesy A. Aiyyer

In summary …In summary …

• AMMA – international with strong research and AMMA – international with strong research and outreach already established after many years of outreach already established after many years of work – Europe, UK & US are major players in the work – Europe, UK & US are major players in the field phasefield phase

• UCAR-AAAS African Initiative could help AMMA UCAR-AAAS African Initiative could help AMMA strategic goalsstrategic goals that might otherwise be difficult to that might otherwise be difficult to maintain after the field phase is completed maintain after the field phase is completed

• Research by NCAR scientists and its modeling infra-Research by NCAR scientists and its modeling infra-structure is a contribution to AMMA and potentially structure is a contribution to AMMA and potentially to the UCAR/AAAS African Initiativeto the UCAR/AAAS African Initiative