1

Recent development of the data assimilation, model and

deterministic forecast at ECMWF

Adrian Simmons Data Division, Research Department

and

Alfred Hofstadler Met. Apps. Section, Operations Department

2

Operational data assimilation before 29 June 2004

12h 4D-Var with long data cut-off

00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00

Long cut-off4D-Var (12

h)

AN

AN

00 UTC FC

12 UTC FC

3

From 29 June 2004

The Early Delivery System

00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00

Delayed cut-off

4D-Var (12 h)

ANAN

FCFC

AN ANEarly Delivery Analysis4D-Var (6 h)

00 UTC FC

12 UTC FC

Early Delivery System gains from:

- using 00 and 12UTC data earlier in window of 12h 4D-Var

- using slightly more data in 12h 4D-Var

Early Delivery System loses from

- using less data in 6h 4D-Var

4

Radiosondes arriving between 0401 and 0800 UTC

25 March 2004 Number of soundings = 35

5

Four subsequent operational changes

• 28 September 2004 – IFS cycle 28r3

• 18 October 2004 – IFS cycle 28r4

• 5 April 2005 – IFS cycle 29r1

• 28 June 2005 – IFS cycle 29r2

Day

Anomaly correlation of 500hPa forecasts for Europe

Mean over 186 days since 1 Dec 2004

Cycle 29r2

Cycle 29r1

6

EUMETSAT ATOVS Retransmission Service (EARS)

7

Relative humidity along Greenwich meridian

5.0m/s

80°S80°S

70°S 70°S

60°S60°S

50°S 50°S

40°S40°S

30°S 30°S

20°S20°S

10°S 10°S

0°0°

10°N 10°N

20°N20°N

30°N 30°N

40°N40°N

50°N 50°N

60°N60°N

70°N 70°N

80°N80°N

160°W

160°W 140°W

140°W 120°W

120°W 100°W

100°W 80°W

80°W 60°W

60°W 40°W

40°W 20°W

20°W 0°

0° 20°E

20°E 40°E

40°E 60°E

60°E 80°E

80°E 100°E

100°E 120°E

120°E 140°E

140°E 160°E

160°E

5.0m/s

80°S80°S

70°S 70°S

60°S60°S

50°S 50°S

40°S40°S

30°S 30°S

20°S20°S

10°S 10°S

0°0°

10°N 10°N

20°N20°N

30°N 30°N

40°N40°N

50°N 50°N

60°N60°N

70°N 70°N

80°N80°N

160°W

160°W 140°W

140°W 120°W

120°W 100°W

100°W 80°W

80°W 60°W

60°W 40°W

40°W 20°W

20°W 0°

0° 20°E

20°E 40°E

40°E 60°E

60°E 80°E

80°E 100°E

100°E 120°E

120°E 140°E

140°E 160°E

160°E

300hPa wind Meteosat-7 increments Meteosat-8 increments

Assimilation of MSG water-vapour radiances

8

Total ozone9 Sept 2004

Operations, no SCIAMACHY

Pre-operational test, including SCIAMACHY retrievals from KNMI

TOMS

9

Wavelet Jb: horizontal and vertical correlations for vorticity North America

Equatorial Pacific

Average vertical correlations

Horizontal correlations at level 39 (~500hPa)

10

New moist boundary layer scheme

METEOSAT visible 10 Dec 2004 Impact on low-cloud cover 8-16 Dec 2004

-0.4

-0.3

-0.2

-0.10.1

0.2

0.3

0.4

KM

K

Stratocumulusdry PBL

zcbzi

zi

KMMoist combined

mass-flux/K-diffusion PBL

11

Bias-correction of surface-pressure observations

Altamera, Brazil

December 2004 April 2005

12

Assimilation of rain-affected microwave radiancesand improvement of humidity analysis

Rain Asm

Hurricane CharleyTrack forecasts from 12 UTC 11 Aug

2004

e-suite ops

Global 1.74 1.90N. Hemisphere 1.63 1.71Tropics 2.12 2.43S. Hemisphere 1.53 1.62N. Atlantic 1.63 1.69N. Pacific 1.57 1.69

(kg/m2)

Comparison of cycle 29r2e-suite and operations

with independent TCWV retrievals from Jasonmicrowave radiometer

13

Also included:

• Refinements to use of ATOVS and AIRS

• Improved use of TEMP and SYNOP humidity observations

• Monitoring of TCWV from ground-based GPS receivers

• Use of METAR observations; discontinue use of PAOBS

• Lower surface-pressure obs errors for automatic stations

• Use of Meteosat-8 (MSG) winds

• MODIS winds from second satellite, and with reduced errors

• Simulated GEO imagery as forecast product

• Jb statistics from new ensemble data assimilation

• Use of SMHI Baltic sea-ice analysis

• Small revisions to surface, convection and cloud schemes

• Radiation frequency reduced from three hourly to hourly

• Better vertical diffusion in first minimization of 4D-Var

14

T799 orography

T799 model resolution for deterministic forecast

T95/255/799 for 4D-Var

10m wind T799

15

91-level vertical resolution

used UJPprofiler-windspeed Japanexp:eilv L91/L60 2004010500-2004013112(12)

nobsexp

0 33568 56445 26291 7821 681 0 0 0 0 0 0 0 0 0 0

exp - ref

+0 -11 -13 -5

+10 +14 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0

0 2 4 6 8

STD.DEV

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

-6 -4 -2 0 2 4 6

BIAS OF SPEED

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

background departure o-b(ref)background departure o-banalysis departure o-a(ref)analysis departure o-a

used TTEMP-T N.Hemisexp:eilv L91/L60 2004010500-2004013112(12)

nobsexp

50366 75192 85693 72586 53338 48908 45852 48907 45909 50690 41975 41264 37500 32256 28557 6947

exp - ref

-71 -12 +21 +27 +24 +115 +295 +432 +228 +215 +189 +227 +61 +5 -73 -61

0 1 2 3 4

STD.DEV

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

-3 -2 -1 0 1 2 3

BIAS

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

background departure o-b(ref)

background departure o-banalysis departure o-a(ref)analysis departure o-a

used TTEMP-T Tropicsexp:eilv L91/L60 2004010500-2004013112(12)

nobsexp

8334 9927 14484 14627 11266 8419 6054 5486 6117 5953 6199 6455 5770 4483 3160 687

exp - ref

+12 -2

+10 +6 -3 -1 -2 -4 -1

+220 +189 +136 +119

-73 -53 -4

0 1 2 3 4

STD.DEV

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

-3 -2 -1 0 1 2 3

BIAS

1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5

background departure o-b(ref)

background departure o-banalysis departure o-a(ref)analysis departure o-a

Fit of L91 and L60 background and analysis to NH radiosonde T

K

L60

L91

16

Higher horizontal and vertical resolution

Anomaly correlation of 500hPa height for northern hemisphere

T511 L60

T799 L91

Day

Mean over 148 cases from 1 August 2004

17

Higher horizontal and vertical resolution

Anomaly correlation of 500hPa height for Europe

T511 L60

T799 L91

Day

Mean over 148 cases from 1 August 2004

18

Higher horizontal and vertical resolution

Anomaly correlation of 500hPa height for Europe

T799 L60

T799 L91

Day

Mean over 148 cases from 1 August 2004

19

Resolution Upgrades – Atmosphere (A.Hofstadler)

Deterministic EPS MOFC

Current Upgrade Current Upgrade Current Upgrade

Spectral T511 T799 T255 T399 T159 T159

Gaussian N256 N400 N128 N200 N80 N80

Dissemination (LL)

0.5 0.25 1.0 0.5 1.5 1.5

ML - Vertical Resolution

60 91 40 62 40 62

• No increase in pressure levels planned

20

Resolution Upgrades - Waves

Deterministic EPS European shelf MOFC

Current Upgrade Current Upgrade Current Upgrade Current Upgrade

Lat/Lon 0.5 0.36 1.0 1.0 0.25 0.25 1.5 1.5

Dissemination/LL 0.5 0.25 1.0 1.0 0.25 0.25 1.5 1.5

Frequencies 30 30 25 30 30 30 25 25

Directions 24 24 12 24 24 24 12 12

21

Timetable for resolution changes

• Mid June: First operational testing

• End June: First technical test datasets for selected operational suites available in MARS

• July-September: Operational e-suite

‑ Meteorological test datasets for all operational suites available in MARS

‑ Parallel test dissemination for selected dates

• End September: Implementation

• December: increase in run-length for medium-range from 10 to 15 days, including VAREPS

• Spring 2006: linking MOFC to VAREPS

22

Technical impact on users

• Field sizes‑ Model output (SH and GG) -> x 2.5

‑ Lat/Lon -> x 4

‑ Extra model levels -> x 1.5

• Dissemination‑ Problem with GG/AUTOMATIC

‑ Choosing of nearest “new” model level

‑ Nearest GRID point coordinates for Weather Parameter requests will

change. Member States have to choose new GRID point coordinates or

rely on interpolation.

‑ Line capacity

‑ Production schedule should stay the same

• MS jobs‑ Check new disk space, memory, CPU, line bandwidth requirements

23

Technical impact on users (cont.)

• MS projects‑ Use test data sets to run “e-suites” and decide on new

configuration

‑ Review resource requirements (disk space, memory, CPU, line bandwidth)

• EMOSLIB 281‑ New Gaussian definitions

‑ New automatic truncation

‑ Will become default version

‑ MARS and Metview_new have been relinked

‑ MS graphics applications (Metview and MAGICS) need to be relinked