High-resolution Regional Reanalyses for Europe and Germany€¦ · " COSMO-REA2 (2.0 km): Jun–Aug 2011 " Multi-parameter evaluation " Representation of spatio-temporal variability

High-resolution Regional Reanalyses for Europe and Germany Christian Ohlwein1,2, Jan Keller1,4, Petra Friederichs2, Andreas Hense2, Susanne Crewell3, Sabrina Bentzien1,2, Christoph Bollmeyer1,2, Jessica Keune1,2, Ieda Pscheidt1,2, Stephanie Redl1,3, Sandra Steinke1,3, David Willms1,2 1 Hans-Ertel-Centre for Weather Research – Climate Monitoring Branch 2 Meteorological Institute, University of Bonn 3 Institute for Geophysics and Meteorology, University Cologne 4 Deutscher Wetterdienst DWD In cooperation with Stefan Kollet6,7, Mauro Sulis6 6 Meteorological Institute, University of Bonn 7 Institute for Bio- and Geosciences, Agrosphere (IBG-3), Research Centre Jülich

DMG-‐Kolloquium, Berlin, 20 January 2014

Approach è Build up a regional reanalysis system

Christian Ohlwein ■ Hans-Ertel-Centre for Weather Research ■ Climate Monitoring Branch

Objective è Develop methods for monitoring regional climate for

operational use at the DWD § Synthesis of heterogeneous observations § High resolution in space and time § Assessment of uncertainty

Outline è Towards a regional reanalysis system

§ Set-up and characteristics § Evaluation

è Perspectives § Next steps and new approaches


Atmospheric Reanalyses

è Data assimilation with a physical model § Synthesize heterogeneous monitoring networks § Provide four-dimensional fields

§ Physically consistent in space and time and between variables § Unobserved variables

è Alternative concepts § Spatio-temporal interpolation § Dynamical downscaling from global reanalyes § …


Observations Data Assimilation Physical Model

Atmospheric Reanalyses


Current reanalyses ERA-Interim ECMWF T255 L60 1989-present

ERA-40 ECMWF T159 L60 1958-2001

Japanese Reanalysis (JRA-25) JMA T106 L40 1979-2004

NCEP Reanalysis AMIP-II (R2) NCEP T62 L28 1979-present

NCEP Reanalysis I (R1) NCEP T62 L28 1948-present

MERRA NASA 0.5° x 0.5° 1979-2010

Climate Forecast System Reanalysis (CFSR) NCEP T382 L64 1979-????

20th Century Reanalysis (20CR) NOAA T62 L28 1871-2008

North American Regional Reanalysis (NARR) NCEP 32 km 1979-present

Arctic System Reanalysis (ASR) PMG 10-20 km 2000-2010 www.reanalysis.org

Regional Reanalyses


COSMO-REA2 COSMO-DE (2 km)

Regional Reanalysis System


Continuous nudging SYNOP, SHIP, PILOT, TEMP, AIREP, AMDAR, ACARS,…

SST analysis (daily) Snow analysis (6-hourly)

COSMO-REA6 (6.2 km)

§  CORDEX EUR-11 domain §  Data assimilation …

ERA-Interim Reanalysis (T255)

Soil moisture analysis (SMA)

COSMO-REA2 (2.0 km)

§  COSMO-DE domain §  Data assimilation … Latent heat nudging (LHN)

Continuous nudging SYNOP, SHIP, PILOT, TEMP, AIREP, AMDAR, ACARS,…

SST analysis (daily) Snow analysis (6-hourly)

Soil moisture analysis (SMA)

Latent heat nudging (LHN)

Regional Reanalysis System


COSMO-DS6 (6.2 km)

§  CORDEX EUR-11 domain §  Downscaling only

ERA-Interim Reanalysis (T255)

Model Output è Domain

§ REA6: 848 × 824 grid points § REA2: … × … grid points

è Variables § ≈ 150 fields (2D/3D) § Output interval

§ 60 min (3D) § 15 min (2D)

è Status § COSMO-REA6: 5 years (2007–2011) § COSMO-REA2: Selected months…


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i=1 i=2 i=3 i=4

i=1

i=2

i=3

i=4

i=1 i=2 i=3 i=4 i=5 i=6 i=7 i=8

j=1

j=2

j=3

j=4

j=5

j=6

j=7

j=8

Setup B (equal volumes)

CO

SM

O-R

EA

6

CO

RD

EX

EU

R-1

1





Model Output (REA6/DS6)


IQ D

ISTA

NCE

[mm

/3h]

DJF

0.00

0.04

0.08

JJA

03 06 09 12 15 18 21 00UTC

0.00

0.04

0.08

0.12

0.16

ERA-INTERIMCOSMO-DSCOSMO-REA6

Precipitation – Distribution


*) cf. Thorarinsdottir et al. (2013): Using proper divergence functions to evaluate climate models

Integrated Quadratic Distance* (IQD) COSMO-CORDEX / German SYNOP stations (2011)

Precipitation – Extremes

<0.1 0.1−1.0 1.0−5.0 5.0−10.0 >10.00.0

0.5

1.0

1.5

2.0

2.5

Precipitation [mm/3h]

Occ

uren

ces

[x10

6 ]

SYNOPCOSMO−REACOSMO−DSERA−INTERIM

20−30 30−40 40−50 50−60 >600.0

0.2

0.4

0.6

0.8

1.0

Precipitation [mm/3h]

Occ

uren

ces

[x10

3 ]

SYNOPCOSMO−REACOSMO−DSERA−INTERIM


Histogram of 3-hourly precipitation events at German SYNOP stations (COSMO-REA6/DS6 simulations, 2011)

*) note the change of support

* * 6

6 6

6

Precipitation – Log-Odds Ratio


Log-odds ratio for 3-hourly precipitation events compared to German SYNOP stations (COSMO-REA6 simulations, 2011)

6 6

Model Output (REA6/REA2)


Precipitation – Extremes


Histogram of 3-hourly precipitation events at German SYNOP stations (June–August 2011)

*) note the change of support

* *

Precipitation – Diurnal Cycle


Mean precipitation intensities (>0.1 mm/h) at German SYNOP stations (June–August 2011)

What is a “good” reanalysis? – Difficult to answer…

Further Evaluation è Standard evaluation

§ Analysis increments § Water and energy cycle § …

è Remote sensing data

§ AMSU-B Microwave Humidity Sensor § MSG brightness temperature § IWV from GNSS measurements § Ceilometer measurements § …


Further Evaluation – Clouds


Brightness temperature (10.8 µm) – COSMO-REA (LHN test runs at 2.8 km)

Further Evaluation – Frozen Hydrometeors


AMSU-B COSMO-REA6





Next steps

è Time slots in the past § COSMO-REA6: 1979–1983, … § COSMO-REA2: one year within the RADAR period

è Start operational use at DWD

§ COSMO-REA6 planned to become operational in mid/late 2014


Next steps è Assimilation of rain gauge

measurements § Disaggregation

§ Rain gauge measurements § Covariates such as MSG TB

§ Assimilation via LHN § Prerequisite for long-term

runs of COSMO-REA2


3 August 2007, 02–03 UTC

New approaches

è UERRA: Uncertainties in Ensembles of Regional Re-Analysis § Multi-model ensembles § EU FP7-SPACE: 12 European partners (EURO4M consortium) § HErZ: Ensemble data assimilation


Hybrid LETKF/ensemble nudging

New approaches è Enhanced representation of soil-vegetation-atmosphere processes

§ Integrated modeling system TerrSysMP (ParFlow-CLM3.5-COSMO)


Shrestha et al. (2012)

New approaches è Enhanced representation of soil-vegetation-atmosphere processes

§ Integrated modeling system TerrSysMP (ParFlow-CLM3.5-COSMO)

è Status § Drainage test on CORDEX EUR-11

è Synergies § TR32 and Geoverbund ABC/J § Planned CRC TerraWatt






Summary è Towards a high-resolution regional reanalysis system

§ Current status § COSMO-REA6 (6.2 km): 2011 and 2007–2011 § COSMO-REA2 (2.0 km): Jun–Aug 2011

§ Multi-parameter evaluation

§ Representation of spatio-temporal variability § Coherence between model and independent observations

è Perspectives § Ensemble data assimilation methods § Enhanced representation of soil-vegetation-atmosphere processes


High-resolution Regional Reanalyses for Europe and Germany Christian Ohlwein1,2, Jan Keller1,4, Petra Friederichs2, Andreas Hense2, Susanne Crewell3, Sabrina Bentzien1,2, Christoph Bollmeyer1,2, Jessica Keune1,2, Ieda Pscheidt1,2, Stephanie Redl1,3, Sandra Steinke1,3, David Willms1,2 1 Hans-Ertel-Centre for Weather Research – Climate Monitoring Branch 2 Meteorological Institute, University of Bonn 3 Institute for Geophysics and Meteorology, University Cologne 4 Deutscher Wetterdienst DWD In cooperation with Stefan Kollet6,7, Mauro Sulis6 6 Meteorological Institute, University of Bonn 7 Institute for Bio- and Geosciences, Agrosphere (IBG-3), Research Centre Jülich

DMG-‐Kolloquium, Berlin, 20 January 2014

Documents

High-resolution Regional Reanalyses for Europe and Germany€¦ · " COSMO-REA2 (2.0 km): Jun–Aug 2011 " Multi-parameter evaluation " Representation of spatio-temporal variability