(1) The international AMMA programme (2) AMMA activities ... · PDF fileJean-Luc Redelsperger, THORPEX Sept 2008 (1) The international AMMA programme (2) AMMA activities directly related

Jean-Luc Redelsperger, THORPEX Sept 2008

(1)(1) The international AMMA The international AMMA programmeprogramme

(2)(2) AMMA activities directly related to AMMA activities directly related to THORPEXTHORPEX

Jean-Luc Redelsperger, THORPEX Sept 2008Vapor channel Meteosat

Precipitating Mesoscale Convective Systems

Same key events for Weather and Climate

A coordinated international program on West African monsoon (WAM), its variability and impacts with an emphasis on daily-to-interannual timescales


(1)(1) To improve our understanding of the WAM & itsTo improve our understanding of the WAM & itsinfluence on environment regionally & globallyinfluence on environment regionally & globally

A coordinated international program on West African monsoon (WAM), its variability and impacts with an emphasis on daily-to-interannual timescales

(2)(2) To provide the underpinning science that relates To provide the underpinning science that relates WAM variability to related societal issues in WAM variability to related societal issues in defining & implementing relevant monitoring & defining & implementing relevant monitoring & prediction strategiesprediction strategies

(3)(3) To ensure that the research carried out in AMMA is To ensure that the research carried out in AMMA is effectively integrated with prediction & decision effectively integrated with prediction & decision making activitymaking activity

A long term program launched in 2002, including field experiments and long termobservations

AMMA will be pursued at least up to 2015


Endorsed by major international programmes

(Algeria, Belgium, Benin, Burkina Faso, Cabo Verde, Cameroon, Chad, Congo, Denmark, France, Gabon, Gambia, Germany, Ghana, Guinea Bissau, Guinea Conakry, Italy, Ivory Coast, Mali, Morocco, Mauritania, Netherlands, Niger, Nigeria, Senegal, Spain, Togo, UK, USA)

~ 500 scientists from 30 countries & ~140 institutions (Africa, Europe, USA)

AMMA: An international long term program

Collaboration

Founding Agencies

African Regional Centres

Main Supporting Agencies


Enhanced Obs. Period

Long term Observation Period

2002

Supra-regional(WAM + Ocean)

Meso

Regional

Local

SPACE (km)

2005 2006 2007 2008

1000

10

100

104Catch, Idaf, PhotonPirata, ….

SOP0: Dry phase

SOP1: Monsoon Onset

SOP2: Monsoon Max

SOP3: Late Monsoon, TC1

IOPs

2

IOPs

3

IOPs

SOPs

00

Monsoon Phases 0 1 0

September

<----------------------------------> <------------------------------------------------->

AMMA SOPs

SOP0

_a1

SOP0

_a2

SOP2

_a2

SOP1

_a

3

October November DecemberJune July August

AMMA SOP Year: 2006

2

January March April MayFebruary

SOP1

<---- SOP Ground instruments remaining on site for the whole annual cycle (AMF, Aerosol Measurements, Lidars, …) ----->

<----------------->

SOP3

_a1

SOP3<------->

SOP2

_a3

SOP2

_a1

SOP0 SOP2

Nested Observation Strategy


LOP/EOP observation strategy

(( (( NiameyNiameyDakarDakar

OuagaOuaga

GourmaGourma

OuOuéémméé

SalSal

MesoscaleMesoscale sitessites

PIRATA PIRATA BuoysBuoys

RadioRadio--soundings soundings

Atalante

Nested periods & domains (multiscale approach


Radio soundingsIntensified RS during the SOP

GPS Weather radars

Water Budget QuadrilateralVHF

UHF

ProfilersEOP stationSOP station

SOP AMMA Deployment

SAGA Project

Radio soundingsIntensified RS during the SOP

GPS Weather radars

Water Budget QuadrilateralVHF

UHF

VHF

UHF

ProfilersEOP stationSOP stationEOP stationSOP station

SOP AMMA Deployment

SAGA Project

SOP AMMA Deployment

SAGA Project

1.5 1.6 1.7 1.8 1.9 2

9.6

9.7

9.8

9.9

DjougouDonga

Bira

Béléfoungou

km0 5 10 15 20

Nangatchori

Kopargo

Nalohou

X-Port

Ronsard

Weather radar

UHF profiler

VHF profiler

Disdrometer

GPS station

Photometer

Hydro transect

Scintillometer

IDAF

Chemistry

1.5 1.6 1.7 1.8 1.9 2

9.6

9.7

9.8

9.9

DjougouDonga

Bira

Béléfoungou

km0 5 10 15 20

Nangatchori

Kopargo

Nalohou

1.5 1.6 1.7 1.8 1.9 2

9.6

9.7

9.8

9.9

1.5 1.6 1.7 1.8 1.9 2

9.6

9.7

9.8

9.9

DjougouDonga

Bira

Béléfoungou

km0 5 10 15 20

Nangatchori

Kopargo

Nalohou

X-PortX-Port

RonsardRonsard

Weather radar

UHF profiler

VHF profiler

Disdrometer

GPS station

Photometer

Hydro transect

Scintillometer

IDAF

Chemistry

Weather radar

UHF profiler

VHF profiler

Disdrometer

GPS station

Photometer

Hydro transect

Scintillometer

IDAF

Chemistry

On each mesoscale site

Parakou

Djougou

Rain Recorder

Daily rain

Streamflow Rec.

Piezometer Rec.

Flux station

Met. Station

Radiosounding

Parakou

Djougou

Rain Recorder

Daily rain

Streamflow Rec.

Piezometer Rec.

Flux station

Met. Station

Radiosounding

Rain Recorder

Daily rain

Streamflow Rec.

Piezometer Rec.

Flux station

Met. Station

Radiosounding



West African West African radiosonderadiosonde network during AMMA network during AMMA EOP 2005EOP 2005--20072007

21 stations were active during EOP

Greatest density of RS ever launched (even greater than during GATE 1974)

200 radiosonde operators and technicians working on the network + students and researchers from Africa, the Americas and Europe

ASECNA responsible for consumable management

Parker et al. 2008

established

new

reactivated

2006 only

1/day

2/day

4/day

4/day, up to8/day duringtwo IOPs

inactive


Summary statistics for EOP 2005Summary statistics for EOP 2005--20072007

Improvement of the radiosonde network is one of the big successes of AMMA

During 2006 & 2007 many more sondes were received at operational centers

The success rate was sustained and improved in 2007, with GTS gradually taking over from email transmission

Parker et al. 2008

Month

ly m

ean s

ondes

per

day

, sh

aded

)

Success rate GTSSuccess rate including satellite and email communication

Dakar RTH failure

Niamey lightningdamage


International Science Plan International Science Plan (2005)(2005)

African Science Plan African Science Plan (2006)(2006)

Initiated & steered mainly by North Initiated & steered mainly by North CountriesCountriesLaunched in Niger (2002)Launched in Niger (2002)

2002-2008P

rogr

amP

rogr

ambu

ildin

gbu

ildin

gM

ain

Mai

n or

ient

atio

nsor

ient

atio

ns

200 people, 200 people, 60 Thesis, Summer schools, 60 Thesis, Summer schools, Research FundingResearch Funding

500 people, 30 countries500 people, 30 countries

Building an African scientific Building an African scientific community community Building a strong international Building a strong international scientific communityscientific community

Significant advances on processes Significant advances on processes ((e.g.e.g.aerosol, interactions oceanaerosol, interactions ocean--atmosatmos--land)land)

MultiMulti--disciplinary research disciplinary research

Unique Unique multiscalemultiscale datasetdatasetUpgrade/Restore(soundings, aerosol, Upgrade/Restore(soundings, aerosol,

buoys, hydrology, buoys, hydrology, ……))

Knowledge orientedKnowledge orientedMultiMulti--scale & multiscale & multi--disciplinary with disciplinary with emphasis on geophysics partemphasis on geophysics part

Research Field ExperimentsResearch Field ExperimentsLong term observation network for Long term observation network for geophysicsgeophysics

ISSC: Leading scientists & coordinators of ISSC: Leading scientists & coordinators of major contributing projectsmajor contributing projects

IGB built in a 2nd step after funding of IGB built in a 2nd step after funding of major projectsmajor projects

Initially built by a small group Initially built by a small group (France, UK, USA)(France, UK, USA)MultiMulti--project management => project management => coordination of a coherent program coordination of a coherent program

Com

mun

ityC

omm

unity

Coo

rdin

atio

n C

oord

inat

ion

ACHIEVEMENTS


Initiated & steered mainly by North Initiated & steered mainly by North CountriesCountriesLaunched in Niger (2002)Launched in Niger (2002)

2002-2008P

rogr

amP

rogr

ambu

ildin

gbu

ildin

gM

ain

Mai

n or

ient

atio

nsor

ient

atio

ns

Building an African scientific communityBuilding an African scientific community

Building a strong international scientific Building a strong international scientific communitycommunity

Knowledge orientedKnowledge oriented

MultiMulti--scale & multiscale & multi--disciplinary with disciplinary with emphasis on geophysics partemphasis on geophysics part

Research Field ExperimentsResearch Field ExperimentsLong term observation network for Long term observation network for geophysicsgeophysics

Initially built by a small group (France, Initially built by a small group (France, UK, USA)UK, USA)

MultiMulti--project management => project management => coordination of a coherent programcoordination of a coherent program

Com

mun

ityC

omm

unity

Coo

rdin

atio

n C

oord

inat

ion

FUTUR

To be established & steered together by North To be established & steered together by North & South Countries in consolidating the success & South Countries in consolidating the success of 2002of 2002--2008 phase2008 phase

--Integration of Integration of ““processprocess”” knowledge (WAM knowledge (WAM understanding; NWP/Climate models)understanding; NWP/Climate models)--Scale Integration (up/down)Scale Integration (up/down)--PluriPluri--disciplinarydisciplinary => Interactions Societies=> Interactions Societies--EnvironmentEnvironment--Climate (start with specific pilots)Climate (start with specific pilots)--Relevant monitoring for Application & Relevant monitoring for Application & Research in regard societal issuesResearch in regard societal issues--Applications (High impact weather & climate Applications (High impact weather & climate predictions, EWS, predictions, EWS, ……))

--An African community including scientist, users An African community including scientist, users & decision makers& decision makers (a long (a long wayway))--A community bringing together scientists, A community bringing together scientists, application experts & decision makers, taking in application experts & decision makers, taking in account the North and South componentsaccount the North and South components

--An international program covering all aspects An international program covering all aspects including capacity building and applicationsincluding capacity building and applications--A governing structure to steer this programA governing structure to steer this program--An International Project OfficeAn International Project Office


ISSCISSC

IGBIGB

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

WG1WG1

WG2WG2

WG3WG3

WG4WG4

WG5WG5

WAM & global climate (incl aerosol & chemistry

Water cycle

Surface-atmospherefeedbacks

Prediction of climateimpacts

High impact weather prediction

AMMA National & PanScientific Committees

CCG1CCG1 Climate Modelling

Long term observations (incl satellite)

Capacity building Training

CCG2CCG2

CCG3CCG3

POPOCrossCross--Cutting Cutting GroupsGroups


WG5 High impact weather prediction

Presentation prepared with Chris Presentation prepared with Chris ThorncroftThorncroft Leader of WG5Leader of WG5

Highlight the following contributions to this WG:Highlight the following contributions to this WG:

(1)(1) Tailoring and evaluation of forecast products for users in tropiTailoring and evaluation of forecast products for users in tropical regionscal regions

Forecasting Methods (Handbook) and ProductsForecasting Methods (Handbook) and Products

Evaluation of Forecast Models Evaluation of Forecast Models

(2) Predictability studies and observing system experiments(2) Predictability studies and observing system experiments

Focus on Humidity: Sounding correction and use of microFocus on Humidity: Sounding correction and use of micro--wave over land wave over land

Making use of the enhanced sounding network provided by AMMA Making use of the enhanced sounding network provided by AMMA in in 2006/20072006/2007


(1) Tailoring and Evaluation of Forecast Products

Tailored products

Elaborated for the SOP by Forecasters and Researchers (met observations, satellite and NWP products)

-Feeding a Web site still operational and used

-Weather analyses and forecast charts tailored to West (and North) Africa=> Extended to other Africa region (ACMAD and coll)



Weather analyses and forecast charts based on the SYNERGIE system

The system provides a means through which key features (e.g. convection, AEWs, AEJ) can be graphically represented on a chart to facilitate the transfer of information based on satellite, model analyses and forecasts onto a single chart.


ExtendedExtended toto Southern AfricaSouthern Africa synthetic forecastsynthetic forecast

SASF SASF ValidValid 18z 02/11/0618z 02/11/06

From Z. Mumba ACMAD)



Tailored productsElaborated for the SOP by Forecasters and Researchers (met observations, satellite and NWP products)-Feeding a Web site still operational and used-Weather analyses and forecast charts tailored to West (and North) Africa

=> Extended to other Africa region (ACMAD and coll)

Forecasting HandbookNeed of a forecasters’ handbook for West Africa has been a clear output from SOP preparation and operation

Content-information about our knowledge of the nature and predictability of the key weather systems impacting West Africa-information on prediction methods and available NWP tools that includes the use of ensemble prediction systems.

Mobilizing the funds and human resources to support this project has meant delays in moving forward. More close to AMMA dream ?


Evaluation of forecast models

-Taking place in several groups in AMMA – mainly in the 1-15 day range

-Development of metrics appropriate for the West African region and strong interactions with NWP centers – especially ECMWF, Meteo-France, NCEP and the UK Met Office

-Regional NWP models are being run in West Africa including new high resolution forecast models (few km scale) and cloud-resolving models on West Africa domain (e.g. CASCADE project in UK, Meso-NH France/ECMWF)

Some examples of model evaluations taking place follow



Kamga et al: Evaluating the ECMWF 1-7 day forecastsLatitude of maximum zonally averaged precipitation [10W-10E]

For this parameter (ITCZ position): Worst errors after onset over land Forecast better for D + 3

2

4

6

8

10

12

14

Latit

ude [

degr

ees]

M O N FR I TU E S A T W E D S U N TH U M O N FR I TU E S A T W E D SU N TH U1

M A Y1 2 23 3

JU N14 25 6

JU L17 2 8 8

AU G19 30 10

S EP21

FEW S(black), D +1(red), D +3(navy), D +5(green), D +7(cyan)

may july septMonsoon Onset


Berry et alEvaluation of AEWs in different NWP models (objective tracking technique)

Example: 3-day forecasts of curvature vorticity (shaded) and location of analysed AEW-trough (lines).

-Large model-to-model differences are noted

-Some AEWs appear to be more predictable than others (see x,y)

(b) GFS(a) ECMWF

(c) UKMO (d) MF

x

y

x

y

x

y

x

y

Jean-Luc Redelsperger, THORPEX Sept 2008Analysis Forecast

Day 0

Day 2

Day 1

Day 3

Day 4

Day 5

Berry et al: Composite AEW structures in ECMWF analyses and forecasts – shading is rainfall, contours are curvature vorticity – comparisons with other models are in the paperAll models tend to have poor phase relationship between trough and rainfall – too coupled?


(2) Predictability Studies and Observing System Experiments

Focus on Humidity

(i) Humidity bias correction

a. Automatic correction in NWP system (ECMWF) in CY32r3

b. Taking into account the dependence of bias on the observed RH values

(ii) Correction of sounding humidity biases (AMMA database):

CDF approach and function of (P, RH)

Comparison to AMMA GPS stations

Dedicated campaign for day biases(1-13 Sept. 2008, Snow white reference)

(iii) Assimilation of MW observations over land (Florence Rabier talk on Monday)


RadiosondeRadiosonde (RS) RH Bias correction(RS) RH Bias correction

Comparison with GPS TCWVComparison with GPS TCWV

UNCORRECTED RS

CORRECTED RS

Agusti-Panareda et al


Correction of Correction of humidity biaseshumidity biases of radiosondes of radiosondes during theduring the AMMA SOPAMMA SOP--2006 2006

•• Differential Differential humidity biashumidity bias (left panel) between(left panel) between VaisalaVaisala RS80RS80--A & RS92A & RS92 sondessondesresulting from the CDF matching applied to AMMA2006 Niamey soundresulting from the CDF matching applied to AMMA2006 Niamey soundings as ings as confirmed by the GPS independent measurements. confirmed by the GPS independent measurements.

•• The The impact of this correctionimpact of this correction is major as illustrated by the time series of is major as illustrated by the time series of convective available potential energy convective available potential energy CAPECAPE (right panel) at Niamey (1(right panel) at Niamey (1--12 12 August 2006) from raw soundings (dashed line) & corrected one (sAugust 2006) from raw soundings (dashed line) & corrected one (straight line)traight line)

Nuret el al. 2008

-4-8

-12

StrongStrong dry dry biasbias (up to 15%) (up to 15%) HightHight impact on CAPEimpact on CAPE


AMMAAMMA--SCOUT H20 Campaign SCOUT H20 Campaign •• Issue:Issue: humidity bias correctionhumidity bias correction•• Past available Past available Sondes IntercomparisonSondes Intercomparison campaignscampaigns

(RS92, MODEM) with reference (RS92, MODEM) with reference sondessondes (SW or CFH) (SW or CFH) –– Maurice 2005, Maurice 2005, YoneyamaYoneyama 2007, TICOSONDE 2005, AWEX2007, TICOSONDE 2005, AWEX--G G –– not sufficientnot sufficient to document the bias during the dayto document the bias during the day

•• AMMAAMMA--SCOUT campaign NiameySCOUT campaign Niamey (1(1--13 Sept. 2008)13 Sept. 2008)–– Document daytime absolute humidity bias of RS92 and M2K2 over WDocument daytime absolute humidity bias of RS92 and M2K2 over West est

AfricaAfrica•• Results:Results:

–– 17 17 intercomparisonintercomparison flights with 3 flights with 3 sondessondes (RS92, MODEM(RS92, MODEM--M2K2, SW) M2K2, SW) –– Different solar elevations (8 and 12h solar time)Different solar elevations (8 and 12h solar time)–– different humidity conditions: dry/monsoon surges different humidity conditions: dry/monsoon surges –– GPSGPS observations and other SCOUT flights during the night (RS92 andobservations and other SCOUT flights during the night (RS92 and SW) SW)

•• Impacts:Impacts: correct AMMA correct AMMA sondessondes andand–– correctioncorrection tables to be used by tables to be used by NWPNWP centres just before the assimilation. centres just before the assimilation. –– calibration of satellitescalibration of satellites radiancesradiances–– Provide nonProvide non--biased humidity biased humidity ““anchor pointsanchor points”” for the for the VarVar--BCBC (key for (key for

assimilation systems)assimilation systems)

Participants: ASECNA, CNRM/MF, LAREG/IGN, ETHZ, SA Participants: ASECNA, CNRM/MF, LAREG/IGN, ETHZ, SA Funding: MF, CNES, APIFunding: MF, CNES, API--AMMAAMMA

IWV from GPS

RH(T) at 12Z

Example ofRS92, M2K2, SW

profiles

Impact of assimilating Impact of assimilating µµWave observations over landWave observations over land

From 01/08/2006 to 14/09/2006From 01/08/2006 to 14/09/2006

Moistening of the Atmosphere

Drying of the Atmosphere

TCWV time series from GPS (Ouagadougou) TCWV time series from GPS (Ouagadougou) compared tocompared to REFREF && EXPEXP

Karbou et al 2008

ReferenceReference ExperimentExperiment

REF

EXPGPS

Density of assimilated AMSUDensity of assimilated AMSU--B Ch5 during B Ch5 during August 2006August 2006


Current numerical studies Current numerical studies Contributing Groups listed according to Contributing Groups listed according to modelmodel

(a)(a) ECMWF (AgustiECMWF (Agusti--Panareda, Beljaars, Cardinali et al)Panareda, Beljaars, Cardinali et al)

* Data impact being explored by comparison with operational ana* Data impact being explored by comparison with operational analyses lyses and with and withought moisture bias correction and with and withought moisture bias correction –– emphasis on emphasis on soundingssoundings

*Special reanalysis for AMMA*Special reanalysis for AMMA

(b) ECMWF (R.(b) ECMWF (R. CornforthCornforth, B. Hoskins, T. Palmer), B. Hoskins, T. Palmer)

* Investigating the use of Moist Singular Vectors to improve * Investigating the use of Moist Singular Vectors to improve understanding ofunderstanding of AEWsAEWs and their predictability. Possible links to and their predictability. Possible links to improving initialization ofimproving initialization of EPSsEPSs..

(c) Meteo(c) Meteo--France (Rabier, Karbou, Nuret et al)France (Rabier, Karbou, Nuret et al)

* Testing impact of satellite measurements from AMSU and SSMI ov* Testing impact of satellite measurements from AMSU and SSMI over er landland

* Plans to investigate impact of SEVIRI CSR and soundings* Plans to investigate impact of SEVIRI CSR and soundings




(d) NCEP (Pan, Thiaw, Vintzileos)

* New CFS-Reanalysis has completed the summer of 2006 that includes the AMMA special observations.

* Data impacts being explored by comparison with operational analyses

(e) NCEP-GFS model (S. Majumdar, C. Thorncroft)

* Propose to look at impacts of all data streams in the West African and Tropical Atlantic regions (relies on funding)

(f) NRL (R Langland)

* Analyzing differences (e.g. RMS error of 500mb height globally) between several models (e.g. GFS, ECMWF, UKMO, Canada, NOGAPS etc) to see what radiosondes (including AMMA sondes) have important information.

(g) ARW (WRF) (R. Torn)

* Using ensemble-based sensitivity analysis to understand impact of initial condition errors on AEW forecasts and estimate the impact of observations including AMMA-SOP observations on forecasts over West Africa.


Data impacts Data impacts

Results on the issue of data impacts (ECMWF & Results on the issue of data impacts (ECMWF & MeteoMeteo--France) were included in Monday France) were included in Monday talk by Florence talk by Florence RabierRabier::

•• The humidity bias correction in theThe humidity bias correction in the radiosoundingsradiosoundings in the AMMA region is beneficial.in the AMMA region is beneficial.

•• The additional AMMAThe additional AMMA radiosoundingsradiosoundings has a significant positive impact on the analyses has a significant positive impact on the analyses and rainfall rates.and rainfall rates.

•• Using more satellite data over land has also had a large impactUsing more satellite data over land has also had a large impact on the global tropicson the global tropics

--------------------------------------------------------------------------------------------------------------------------------------

⇒⇒Need to coordinate NWP experiments to be able to make strong recNeed to coordinate NWP experiments to be able to make strong recommendations on ommendations on sounding networksounding network

⇒⇒Project to fund such studies and the functioning of the soundingProject to fund such studies and the functioning of the sounding/GPS network up to 2010 /GPS network up to 2010

*EC DG/DEV: not secured at present time*EC DG/DEV: not secured at present time

*Role/Help of THORPEX ?*Role/Help of THORPEX ?




Reanalyses Reanalyses for the AMMA SOPfor the AMMA SOP

Planned Planned reanalysesreanalyses that utilize biasthat utilize bias--correctedcorrected radiosoundingsradiosoundings, as well as all , as well as all available data (including that which was not available in realavailable data (including that which was not available in real--time)time)

--Special Special ReanalysesReanalyses are being created at ECMWF are being created at ECMWF

--3030--year reanalysis (1979year reanalysis (1979--2009) is planned by NCEP that include the AMMA 2009) is planned by NCEP that include the AMMA observations (with bias correction for soundings)observations (with bias correction for soundings)

--A proposal also exists to carry out a special AMMA SOP reanalysA proposal also exists to carry out a special AMMA SOP reanalysis at is at NASA.(MERRA) NASA.(MERRA) –– depends on proposal being fundeddepends on proposal being funded

--ReanalysesReanalyses on short periods at on short periods at MeteoMeteo--France France


Period: 1 May Period: 1 May –– 30 September 200630 September 2006

Resolution: T511 (~40 km), L91Resolution: T511 (~40 km), L91

IFS cycle with improved physics: CY32r3 (IFS cycle with improved physics: CY32r3 (BechtoldBechtold et al. 2008) et al. 2008)

AMMA AMMA radiosonderadiosonde humidity bias correction humidity bias correction

Extra data used: Extra data used: sondesonde profiles of wind, temperature and humidity extracted from profiles of wind, temperature and humidity extracted from the AMMA databasethe AMMA database

ECMWF’s AMMA reanalysis(Agustí-Panareda, Beljaars, Vasiljevic, Cardinali, Dragosavac, Andersson, et coll)

6063 high resolution profiles (radiosondes, dropsondes) from ground-stations, 3 research vessels, 2 research aircrafts

110 high resolution driftsondes from research Gondolas (NCAR & CNES).

101 dropsondes from GTS received at Météo-France (low resolution)

7317 wind profiles from pilots obtained via GTS at Météo-France.

GTS TEMP (low-resolution) data from Météo-France & ECMWF over West Africa



Curvature Curvature VorticityVorticity(1day forecast) (1day forecast)

sensitivity to analysissensitivity to analysis

700 hPa Meridional Wind

Mid-Troposphere θe

Ensemble-based sensitivity calculations using 96 ensemble forecasts from an ensemble Karman filter coupled to the WRF model at 36km resolution during Sep 2006 (R. Thorn)


Precipitation Sensitivity (1 day forecast)Precipitation Sensitivity (1 day forecast)

Mid-Troposphere θe

Lower-Troposphere θe


Electronic Special Issue but a hard copy version will be made for distribution in West Africa

(collaboration with AMS). Expected papers:

• Babatunde and Omotosho: Predicting onset dates of the rainy season over West Africa by numerical methods

• Berry et al: Intercomparision of African easterly wave representation in operational weather prediction models.

•Bock et al: Verification of radiosonde humidity data and NWP model analyses and forecasts during AMMA with GPSprecipitable water estimates

• Cornforth and Hoskins: Applying moist singular vectors to understanding and forecasting African easterly waves

• Diaz and Semazzi: A New Mechanism on the Role of West African Coastal Upwelling in the Genesis of Tropical Cyclones

• Faccani, C., F. Rabier, A. Agusti-Panareda, et al: The impact of the AMMA radiosonde data on the French globalassimialtion and forecast system

•Karbou et al: Impact of microwaveland emissivities on the assimilation of AMSU measurements over land

•Knippertz and Fink: Dynamics and predictability of dry-season precipitation episodes in tropical West Africa

• Lafore et al: Forecasting activities during the Summer 2006 SOP of AMMA: Proposition of a Synthetic Analysis specific to the West Africa

• Ross and Krishnamurti: Relative roles of dynamics and diabatics in the development of NAMMA AEW

• Sultan et al: Medium-lead prediction of intraseasonal oscillations in West Africa

• Tompkins et al: Monthly and Seasonal forecsating systems of ECMWF for West Africa

• Torn: Ensemble-based sensitivity analysis applied to African Easterly Waves

3. Special Issue in Weather & Forecasting

USE WRF TO PREDICT THE WITHDRAW OF MENINGITIS EPIDEMIC BASED on 40% RH THRESHOLD

Preliminary results from Semazzi, Mera, Laing

Average RH (%) for the day on 5/16/2006 in Niamey. 40% is the threshold number that defines the end of the meningitis (dry) season.

0

40

80

Observation(Niamey)

WRF NNRP1 FNL (GFS)

Rel

ativ

e H

umid

ity (%

)


More details on AMMA in Redelsperger et al, BAMS 2006on AMMA soundings in Parker et al, BAMS 2008

Documents

(1) The international AMMA programme (2) AMMA activities ... · PDF fileJean-Luc Redelsperger, THORPEX Sept 2008 (1) The international AMMA programme (2) AMMA activities directly related