© crown copyright 2012. source: met office dale barker, tomas landelius, eric bazile, christoph...

© Crown Copyright 2012. Source: Met Office

Dale Barker, Tomas Landelius, Eric Bazile, Christoph Frei, Phil Jones

2 April 2012

EURO4M – WP2: Regional Reanalysis Overview

© Crown Copyright 2012 Source: Met Office


EURO4M WP2

• WP2.1 Building capacity for advanced regional data assimilation (MetO)• WP2.2 Dynamical downscaling of ERA (SMHI).• WP2.3 2D mesoscale downscaling (Météo France).• WP2.4 Evaluation (MeteoSwiss).• WP2.5 Improvement of input data for reanalyses (UEA)

Now


WP2.1 Building capacity for advanced regional data assimilation

Current

12km grid

480 x 384

• Horizontal domain unchanged from last year.• Decision made in FY2011-12 to align EURO4M vertical levels, physics, etc with global NWP/climate model (previously aligned with regional NWP ensemble).


UM Running atECMWF

ECMWF

“interface”

Met Office


Regional NWP – Why Bother?

Regional NWP + Regional DA

Upper-Air Temperature

Upper-Air Wind Speed

PMSL

6hrly Acc. Precipitation

Surface Wind-Speed T+6 – T+48 T+0 – T+6

Cloud Amount T+0 – T+48 T+0 – T+6

Visibility T+0 – T+48 T+0 – T+12

Surface Temperature T+0 – T+48 (UK only) T+0 – T+12/24 (NAE/UK)

Benefit Of European Regional NWP vs 25km global model (UM):

Focus for EURO4M: ‘Regional Reanalysis – Why Bother?’


ERA-Interim EURO4M

• 12km, 70 levels

• 12-36km 4D-Var

• 6-hour analysis window

• assimilate:• conventional obs incl visibility

• satellite radiances

• Ground-based GPS

• Cloud

• Precipitation

• Initial state and boundary

conditions from ERA-Interim/Clim analyses

• T255* (80km), 60 levels

• T159 (125km) 4D-Var

• 12-hour analysis window

• Assimilate:• conventional obs

• satellite radiances

Global/Regional Reanalysis Configurations

* Note ERA-Clim up to T511 (~40km)


First attempt at reanalysis...

May 2010

June 2010

July 2010

• Floods in Poland,

eastern Europe

• Severe storms

France/Spain

• Russian heatwave

spreading West,

forest fires


Russian heatwave, July 2010

Tmax10-07-10

ERA-Interim

12km EURO4M

e-obs


Verification vs Radiosonde

T+0 T+6

European Temperature rms error: May-July 2010

ERA-Interim

EURO4M 12km GA3: See Renshaw talk


Developments for 2012/13

• Variational bias correction• ODB – obs monitoring. ECMWF collaboration.• Extend observations dataset• Cloud and Precipitation assimilation• Validation – extreme statistics• Collaborate on cross-validation

• ‘Pre-Production’ Reanalysis: 2010 – 2011 period• Impact of 4D-Var assimilation resolution (12-36km)


3D-Var Re-analysis at 22 km, 60Levels over Europe (SMHI)

2D analysis at x ~5 km

x ~ 5 km over Europe

Downscaling

Courtesy of T. Landelius (SMHI)

More observations

Dynamical downscaling and reanalysis over Europe (WP2.2 – 2.3)

By adding details with topography and more observations, the quality of the analysis should improve … ~ 4000 obs (1200 over France)


WP2.3 2D reanalysis (SMHI)

HIRLAM 22 km Downscaled to 5 km MESAN t2m analysis(observations as black dots)


WP2.3 observations for2D reanalysis (SMHI)

In total some 10,000 unique stations.

This is still far from all observations available in the national archives!

GA3: See Unden, Landelius talks


# Validation of the analyses• Against observations (particularly for T2m, Rh2m, 24-h cumulated precipitation)• Assessment of the snow depth and the river flow by using a surface scheme and a

hydrological module forced with reanalyses surface variables.

# Improvement of the downscaling method:• Problem of the vertical interpolation over the mountainous areas especially for the

temperature ;• usage of a lake climatology to improve the lake surface temperature.

# Development of precipitation analysis, the usage of Tmin and Tmax for reanalysis

# Technical issues:• To create a reanalysis domain (~5km scale) over Europe that best fit SMHI domain (at

22 km scale), i.e. changing the geometry from rotated lat-lon to Lambert conformal);• Converting GRIB files from SMHI to specific format type• Usage of additional observations not available in GTS.

# Specific treatment for the wind with a dynamical adaptation or by DFI ?

WP2.3 Ongoing work

GA3: See Soci talk


Overall Process

WP2.5 Improved Input Data (UEA)

GA3: See Jones talk


WP2.4 Evaluation (MeteoSwiss)

Using existing datasets, reanalyses, and datasets developed in WP1

• Formally begins April 2012.

• MeteoSwiss: precipitation variations in Alpine regions.

• Met Office: Reanalysis sensitivity to resolution, technique. Observation impact.

• SMHI: compare MetO/HIRLAM reanalyses.

• MeteoFrance: Evaluate MESAN/SAFRAN.

• DWD: verify WV, cloud, precip, radiation with CM-SAF Investigate satellite radiance calibration.


WP2.4 Evaluation (MeteoSwiss)

20 km grid 5 km grid

Precipitation at meso-scale in complex topography (Alpine region)

Consistency between obs. datasets (spatial pattern, annual cycle) for precip extremes?

High-resolution regional reanalyses vs. global reanalysis?

Representation of interannual to decadal variations by regional reanalyses?

GA3: See Frei discussion


EURO4M WP2 Deliverables/Milestones

Year 1 Year 2 Year 3 Year 4Now

• Deliverables on track.• Year 1-2, largely preparation (much technical work).• Year 3-4 ‘pre-production’ runs plus evaluation (enhanced collaboration).


Questions/Discussion?

© crown copyright 2012. source: met office dale barker, tomas landelius, eric bazile, christoph...

Documents

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met office wp2

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met office um

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met office overall process