Demands and expectations at SMHI on the European

Reanalysis for observations and climate

Per Undén Tomas LandeliusSMHI

EURO4M

WP1 observational datasets

WP2 reanalysis and evaluation

WP 3 evaluation WP 4

management and coordination

WP 2.1 4D-VAR developments and radar precipitation, a year of data – MO

WP 2.2 3D-VAR downscaling, most of 20 years , 25 km SMHI

WP 2.3 MESAN and SAFRAN downscaling, 12-4 km, MF and SMHI

What SMHI expects from EURO4M

• Dynamical downscaling of ERA data using HIRLAM 3D/4D-VAR – Consistent data set for ~ 20 years or more

• Access to observations additional to the ECMWF archive

• 2D high resolution downscaling of HIRLAM– Using these auxiliary observations– Driven by consistent HIRLAM model fields– Consistent data set ~ 20 years or more

Expect project members to share data

User requirements at SMHI

• 1961 - onwards

• Every 3:rd hour

• 5 km (0.05°)

• Parameters for:

Evaluation of climate change models

Atmospheric environment models

Oceanographical models

Wind energy studies

Hydrological models

Surface radiation models

Observation monitoring and replacement

SMHI KOAKK 40 years for QC of observations for climate

National archives of climate data have discrepancies

Need to be re-checked

– Corrections when necessary and possible

• EERA-40 ? >SMHI KOAKK

• 125 km -> HIRLAM reanalysis 22 km ->11 km? N Europe ?

• MESAN downscaling – at 11 km

Data-assimilation system, model and analysis, unchanged through the period

Analysis product quality improves in time

Observing systems including SST/ ICE improves: Better quality, more data types, higher time frequency

Reanalysis philosophy

Intermittent data assimilation

06 UTC 12 UTC 18 UTC

(06 UTC (12 UTC3 h) 3 h) 3 h)(18 UTC

tid

ITN 4/3 2010

4 Dimensional Variational Data AssimilationIterative fitting of a Forecast trajectory to observationsOver a time window of 6 hours

SMHI expertise and resources

• HIRLAM 3D and 4D-VAR• Observation handling• Re-analysis

– ERA expertise– DAMOCLES coupled

HIRLAM/HIROMB reanalysis

• Surface parameterisation• Cloud parameterisation• Radar and satellite data

and algorithms• HARMONIE (ALADIN)

models and data assimilation 3D(4D)

• MESAN 2D-analysis• OI with anisotrophic

structure functions• Observation processing

including radar, precip, satellite and road stations

• Long operational experience

• ERA-MESAN

FoUp redov

0.0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

2.4

2.7

3.0

HIRLAM ALADIN

High Resolution LimitedArea Modelling

Aire Limitee Adaption Dynamique InterNationale

Improved 2D reanalysis for Europe

• ERA-40 as first guess

• 1980 – 2004

• 00, 06, 12, and 18 UTC

• 11 km (0.1°)

ERA-MESAN

Workpackage 2.2

ERA-Interim downscaling 25 km ENSEMBLES area ? ECMWF observations conv

AMVs? HIRLAM 3D-VAR 25 km Jk ((large-scale mix)) 1989-2009 -> HIRLAM 3D-VAR 11 km

EU area MESAN downscaling

11 km T2m, Td, uv, prec, clouds

3D-VAR developments

Jk MESAN/SAFRAN

developments

Snow/ orography etc Advanced features

VARAN type structure functions

Coupled surf-upper air 3D ?

Validation KNMI/MO

11-4 km

125-79 km

ERA-40 / ERA Interim

ECMWF

HIRLAM

MESAN

22 km

Signatur

• HIRLAM - Large Scale Mixing, LSM Reruns from ECMWF analysis, updating first guess

• Instead: Include ECMWF information in assimilation!

• Related work done with ALADIN at Météo-France

Signatur

Vorticity, model state Short forecast, ECMWF

Constrain Vorticity

• Begin as “simple” as possible: - Vorticity only - Univariate NMC statistics from

ECMWF forecasts, interpolated to HIRLAM RCR geometry

EURO4M

downscaling with HIRLAM 4D-Var

possible areas

(Per Kållberg , Per Dahlgren – SMHI)

HIRLAM rotated lat-long coordinates

S.P. at -35º/20º

three resolutions: 0.2º, 0.15º and 0.1º

294*260 = 76 440 points 0.2º*0.2º (27/-31/-24.7/27.5)

an example

• one day 4D-Var 0.15º*0.15º

• LBC from ERA_Interim

• 1 January 2005 18Z 4D-Var and +12h fcst

• ~215 System Billing units on C1A

• one cycle took ~40 minutes (run on daytime Nov 17)

306x306 points 0.2 x 0.2 °

another example

• one 4D-Var 0.2º*0.2º– 2 outer loops

• LBC from ERA_Interim• +12 h forecasts• Analysis 20 mins • Forecast 5 mins • => 25 mins per cycle

– Possible to run 1D / 2h– Or 12 days / day (but depending on queues etc)

• Special Project at ECMWF? Will apply ....

65 levels inst of 60 och 10 m lowest mod lv inst of 30

Development of the MESAN 2D analysis

Anisotropic structure functions Parameterized downscaling