© European Centre for Medium-Range Weather Forecasts Operational and research activities at ECMWF now and in the future Sarah Keeley Education Officer

© European Centre for Medium-Range Weather Forecasts

Operational and research activities at ECMWF now and in the future

Sarah KeeleyEducation Officer

Erland KällénDirector of Research


ECMWF

An independent intergovernmental organisation

established in 1975

Currently:20 Member States14 Co-operating States



How ECMWF was established

Start of operational activities1978 Installation of first computer system (CRAY 1-A)1979 Start of operations

N48 grid point model – 200km


Current systemIBM Cluster

– Two identical systems for resiliency– 1.5 Petaflops peak performance (1.5×1015)

Operational Model - T1279 (16km)

Ensemble Prediction System - T639 (31km)


Increasing Resolution

~125km ~63km ~39km ~25km


Evolution of ECMWF scores

Adapted and extended from Simmons & Hollingsworth (2002)

~210km

~16km


Physical aspects, included in IFS


Data assimilation



Predictability, diagnostics and extended-range forecasting

The atmosphere is a chaotic system Small errors can grow to have

major impact (butterfly effect) This limits detailed weather

prediction to a week or so ahead

Slowly evolving components of the climate system can give predictability at longer timescales



Meteorological Operations


ECMWF Research

Erland KällénDirector of Research

ECMWF


Outline

Operational scoresData assimilationClouds and surface processesForecast bustsIncreasing resolutionOcean wave predictionReanalysisChemical modelling and assimilation


Quality of 500 hPa forecasts at day 6

Error reduction ↑ ECMWF

UKMO

NCEPERA reforecasts



Model: Physical aspects

Cloud microphysicsConvection scheme revisionsStable boundary layer – roughness lengthsRadiation and aerosols


Focus on improved cloud parametrization:

Freezing level

• Super-cooled liquid layers in mixed phase stratiform cloud (37r3)• Ice water content in cirrus (38r1)• Reduction of drizzle occurrence

mid-level cloud

anvil cirrus

stratocumulus

shallow Cu

de

ep c

on

vec

tio

n frontal

SLW stratus

cirrus

iceliquid


Diagnostics

Forecast busts Severe weather EDA, ENS and model error


Forecast busts over Europe

D+6RMSE > 60mACC < 0.40


Flow anomaly before forecast bust over Europe


CAPE anomaly before forecast bust over Europe


Model: Numerical aspects

Resolution increases–Horizontal: 16 km in 2010 →10 km in 2015 →

≈5 km in 2020–Vertical: 91 → 137 levels in 2013

Fast Legendre transformsNon-hydrostatic model Mass conservation


Surface winds from Lothar storm 26 Dec 1999(11 hour forecast)

T1279 (16 km) T7999 (2.5 km)

Gust speed


ENsemble prediction System (ENS)

EDA, singular vectors and ENS Stochastic physics Monthly forecasting

– MJO skill scores Seasonal forecast System 4

– EUROSIP including NCEP Applications of ENS

– Flooding/drought prediction– Health


Marine Parametrisation

Ocean wave impacts on mixing


Data assimilation

Variational assimilationEnsemble of Data Assimilations (EDA)Ensemble Kalman Filter (EnKF)Surface analysis



Reanalysis (ERA)

Climate monitoring in near real time ERA-20th century reanalysis in preparation Ocean reanalysis


ERA-20CM consistency with ERA-Interim


Time evolution of ocean heat content


Atmospheric composition

Modelling and data assimilation Monitoring and evaluation Impact on NWP – aerosols


Summary

●ECMWF world leader medium range weather forecasting

●Variational and ensemble data assimilation●Very high resolution possible●Ocean surface wave modelling●Atmospheric composition●Reanalysis

Documents

© European Centre for Medium-Range Weather Forecasts Operational and research activities at ECMWF now and in the future Sarah Keeley Education Officer