AGREPS – ACCESS Global and Regional EPS

Michael Naughton, David Smith, Asri Sulaiman CAWCR Earth System Modelling Program GIFS-TIGGE Working Group WMO, Geneva 31 Aug – 2 Sep 2011

The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

AGREPS

• ACCESS • Australian Community Climate and Earth System Simulator • Bureau of Meteorology / CSIRO / Australian universities earth system modelling collaboration based on UK Met Office UM system • ACCESS NWP system operational from 1 Sep 2009 • AGREPS • ACCESS version of Met Office MOGREPS ensemble system • BoM Global Ensemble 2001-2010 • T119 L19 Global Spectral Model • Initial condition perturbations based on T42L19 2-day SH & NH singular vectors • 33 members, 10-day forecast The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

AGREPS – ACCESS short-range ensemble

24-member ensemble designed for short-range forecasting • Regional ensemble over Australian Region (24km resolution, 70 levels) to T+72 • Global ensemble (60km resolution, 70 levels) to T+120 • ETKF for initial condition perts • Stochastic model perturbations • Global run at 0Z and 12Z. Regional run at 6Z & 18Z

HI-RES 5km

ACCESS-R 12 km AGREPS-R 24 km ACCESS-G 40km (N320) – 25km (N512) AGREPS-G 80km (N144) – 60km (N216) Currently running at 37.5 & 80 km The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

AGREPS current status and near-term plans

AGREPS global and Australian regional systems at 80 km & 37.5 km have been implemented and are running daily in research mode since middle of 2011 AGREPS current version based on 2009 MOGREPS version; currently working on upgrading components to current MOGREPS versions Operational implementation date not yet determined • Operational implementation at current resolution is possible on current Sun/Oracle Constellation computer • Operational implementation at intended 60 km & 24 km resolution will require computer upgrade, remains TBD The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

Verification of AGREPS cf ECEPS, GASP-EPS MSLP Brier score

Aust-NZ region 2 months period 7 Sep 2009 – 7 Nov 2009 The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

Spread-skill relationship for AGREPS cf ECEPS

Aust-NZ region 6 mths period Feb to July 2011 The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

Spread-skill relationship for AGREPS cf KMAEPS

KMA plot from UM Users Wkshop talk Different domains, forecast lengths, time periods The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

Spread-skill relationship for AGREPS-R cf AGREPS-G

Aust-NZ region 2 mths period mid-June to mid-Aug The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology

AGREPS science

• Ensembles will be key element of data assimilation through provision of capability for flow-dependent error covariances; we aim to incorporate Met Office hybrid DA approach.

• Ensembles at high resolution will also be needed for SREP; although not included in current SREP plans, as they’re not part of the funded project.

• Investigation of approaches to combining deterministic and EPS forecasts in GOCF/GFE is being considered.

• Comparison of singular vector perturbations with ETKF perturbations in MOGREPS is being considered.

The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology