© Crown copyright Met Office New perspectives for GPCs, their role in the GFCS and a proposed contribution to a ‘World Climate Watch’ Richard Graham, Met

© Crown copyright Met Office

New perspectives for GPCs, their role in the GFCS and a proposed contribution to a ‘World Climate Watch’Richard Graham, Met Office Hadley Centre, acknowledgements to colleagues on CBS ET-ELRF, R. Kolli (WMO), Doug Smith (Met Office)

WMO CCl Technical Conference on Changing Climate and Demands for Climate Services for Sustainable Development

Antalya, Turkey, 16-18 February 2010


Content

Global Producing Centres for long-range forecasts (GPCs) and two associated Lead Centres

• Introduction

• Status, example seasonal forecast products, use at Regional Climate Outlook Forums

• Next steps

• Potential expansion of GPC activities – consistent with the Global Framework for Climate Services


GPCs and associated Lead Centres

• WMO CBS coordination of centres making dynamical global long-range (seasonal) forecasts (LRF)

• guided by ET on Extended and Long-range Forecasts

• 11 WMO-designated GPCs adhering to agreed procedures/standards in LRF – integral part of the WMO GDPFS

• 2 Lead Centres, facilitating user access to GPC products

• Aim: improved access and usability of global LRF products for use by RCCs, RCOFs and NMHSs to aid production of regional/national climate services

GPCs: role in the Climate Services Information System (CSIS)

GPCs and their LCs

Other Centres

Data Centres

obs/research

users

GFCS

CSIS


GPC designation criteria

• have fixed production cycles and time of issuance;

• provide an agreed set of long-range forecast products,

• 2m temp, precip, T850, Z500, SST;

• provide an agreed set of forecast quality measures (WMO Standard Verification System for LRF);

• provide up-to-date information on forecast methodology used;

• make products accessible to users (through website and Lead Centre)


The GPCs (designated 2006 & 2009)

GPC System Config. (ens) Reso. (Atm.) Hindcast Period

Beijing, BCC Coupled (48) T63/L16 1983-2004

ECMWF Coupled (41) T159/L62 1981-2005

Exeter, Met Office Coupled (42) 1.25x1.85/L38 1989-2002

Melbourne, BoM Coupled (30) T47/L17 1980-2006

Montreal, CMC 2-tier (40) T32/T63/T95 1969-2004

Seoul, KMA 2-tier (20) T106/L21 1979-2007

Tokyo, JMA 2-tier (51) T63/L40 1984-2005

Toulouse, Météo-Fr Coupled (41) T63/L31 1979-2007

Washington, NCEP Coupled (40) T62/L64 1981-2004

Moscow, HMC 2-tier (10) 1.1x1.4/L28 1979-2003

Pretoria, SAWS 2-tier - -

GPCs and other prediction centres & multi-models

IRI ENSO plume

APCN-MME EUROSIP: ECMWF, Met Office, Météo-France


WMO Lead Centre for LRF Multi-model Ensembles (LC-LRFMME)

http://www.wmolc.org/

Jointly operated byKorean Met Agency & NOAA NCEP

• collect LRF data from GPCs

• core data: monthly pre-calculated anomalies (EM + members) active

• additional data: hindcast and forecast started but not active

• display GPC forecasts in standard formats

• generate and display an agreed set of MME products

• distribute GPC data (for those GPCs that allow it)

• research into MME techniques and products

Primary functions:




Negative AO, DJF 2009/10pmsl anomalies: observed & and GPC predictions from Nov09 (ensemble mean)

1-tier

2-tier

Observed pmsl anomalies 1 Dec – 10 Feb (wrt 61-90)

From LC-LRFMME websitehttp://www.wmolc.org/




Negative AO, winter 2009/10pmsl anomalies: observed & GPC predictions from Nov09

anomaly sign ‘consistency’

Observed pmsl anomalies 1 Dec – 10 Feb (wrt 61-90)

10-model multi-model EM

1-tier multi-model (6) 2-tier multi-model (4)

multi-model subsets produced interactively from LC-LRFMME website


February 2009 for Horn of Africa March-April-May (MAM) ‘long’ rains: consensus prediction

multi-model prediction from 10 GPCs (LC-LRFMME)

Regional Climate Outlook Forum consensus

Observed precipitation anomalies

category probabilities

45

20

35

ICPAC and GHA country climatologists

GPC products from the LC-LRFMME and LC-SVSLRF now introduced at:

- GHACOF 23 (MAM ‘09)- FOCRAII (JJA ‘09)- PRESAO 12 (JAS ‘09)- GHACOF 24 (SOND ‘09)

Lead Centre for Standard Verification of Long-range forecasts (LC-SVSLRF)

• repository of global SVSLRF scores for GPC forecasts

• ROC maps and diagrams, reliability diagrams, MSSS

• documentation on verification scores (Attachment II-8 of the WMO manual on the GDPFS)

• observation datasets for verification, and code for calculating the SVSLRF scores

http://www.bom.gov.au/wmo/lrfvs/

Jointly operated byBureau of Met. BoM) & Met. Service of Canada (MSC)





Example ROC scores for lower tercile, from LC-SVSLRF: Greater Horn of Africa

ToulouseWashington Exeter

Green = ROC score >0.55

MAM

SON


Next steps…

• GPC and Lead Centre products are ‘up and running’, however still much work to do….

• phase 2 exchange: hindcast data, probability products

• widen range of products

• additional climate indices (e.g. IOD, NAO)

• verification of GPC multi-model products

• encourage increasing standardisation

• GPC hindcast periods, datasets used for HC verification


Potential expansion of GPC roles:

1.WMO Global Seasonal Climate Updates

(the GFCS ‘expects’…, the required monitoring and prediction tools exist)

Topic for discussion session…

Vision(courtesy Dr. Kolli, WMO)

• A global seasonal climate update is issued jointly by experts of the GPCs, related Lead Centres and global data/monitoring centres, with input from regions (RCCs, RCOFs, NMHSs)

• Issued a few days ahead of DJF, MAM, JJA, SON.

Two components:

• monitoring: summary of current and recent climate state

• prediction: major climate indices (e.g., ENSO, North Atlantic Oscillation, Indian Ocean Dipole, etc.) - likely impacts on large-scale temperature and precipitation patterns. Discussion of prediction uncertainties.

Global Seasonal Climate Updates: motivation

• The GFCS should develop the capability to deliver an authoritative consensus on the global outlook for next season.

• The Updates would be an extension of the existing WMO El Niño/La Niña updates.

• Iteration of the Update will help to set the large-scale (dynamical forecast) context for elaboration on regional and national scales (by RCCs, RCOFs, NMHSs)

• The Updates will inform users with global remit (e.g. Aid Agencies), promoting services (CSIS) and priming further consultation with RCCs etc.

Some challenges

• Temperature and precipitation updates intrinsically more problematic than ENSO updates

• Harmonising with regional/national forecasts may not be straightforward (e.g. timing issues)

• Further development of LC-LRFMME products and skill assessments needed.

• Product format? Graphics or text based? NB: translation of probabilities into text can easily lead to miscommunication – recent Met Office experience endorses this!

Way forward

• Proposed CCl/CBS inter-commission expert meeting to scope Global Seasonal Climate Updates

• 2nd quarter 2010 – venue to be decided

• Objectives:

• define methodology

• define content/format

• develop implementation plan

• identify lead coordinators


Potential expansion of GPC roles:

2. Inter-annual to decadal prediction: examples from Met Office decadal

prediction system (DePreSys)

Inter-annual to decadal prediction

• Strong user requirement for inter-annual to decadal predictions for planning and adaptation

• On these timescales changes due to natural climate variability and GHG emissions can be of similar order – need initialised predictions

• Some GPCs are developing initialised decadal predictions, seamless with seasonal predictions.

• Case for global-average temperature proven (Smith et al., 2007), very encouraging evidence for regional skill.

• CMIP5 will begin an international comparison of decadal prediction systems

• It is timely to plan coordination/exchange of decadal predictions among centres with capability, to begin to shape infrastructure for this component in the CSIS of the GFCS.

Assessment of DePreSys ensemble-mean forecast from June 2005Temp. anomalies (wrt 1979-2001) for the (~3.5yr) period June 2005 to Nov 2008

Impact of initialisation on hindcast skill5-year mean (JJASON) surface temp15°x15° averaging

DePreSys-NoAssim correlationDePreSys anomaly correlation

• HadCM3

• 9 member perturbed physics ensemble

• Starting every Nov from 1960 to 2005

DePreSys

Skill of DePreSys annual precipitation forecasts:Anomaly correlation, November hindcasts 1979-2001, 35°x35° averaging (verification = GPCP)

NoAssim

Yea

r 1

Yea

r 2

Summary

• WMO CBS (working with CCl) has established GPCs and associated Lead Centres for multi-modelling and verification - strengthening infrastructure for LRF

• Forecast and verification products are available to RCCs / NMHSs / RCOFs - active use is being made at RCOFs

• A significant new contribution is proposed: WMO Global Seasonal Climate Updates (monitoring and outlook) -responds to user demand, developing GPC infrastructure, and GFCS vision.

• It is now timely to plan an experimental coordination/exchange of decadal predictions, along lines defined for LRF, to begin to shape this timescale within the CSIS

Thank you! Any questions?

Rainfall anomalies JJA 2009

Observed precip anomalies JJA 2009 (wrt 79-00) CAMS_OPI

10-model multi-model EM

Documents

© Crown copyright Met Office New perspectives for GPCs, their role in the GFCS and a proposed contribution to a ‘World Climate Watch’ Richard Graham, Met