_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

1

Assimilation of ATOVS and AMDAR data in the ALADIN

3d-var system

Gergely Bölöni/Roger Randriamampianina/

Regina Szoták/Gabriella Csima

25th EWGLAM and 10th SRNWP meetings

6-9 October, Lisbon

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

2

Main research directions(ALADIN and generally)

The two is interacting (very simple grouping!)

Methods New observation types

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25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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ALADIN 3d-var in HungaryParallel suite:• 6 hour cycle

– background: ALADIN forecast– initialization: DFI– LBC: ARPEGE long cut-off analyses

• background errors: NMC method• observations: radiosondes (TEMP) and local surface (SYNOP) data

(Operational is dynamical adaptation!)

Testings:• use of satellite (ATOVS) data• use of aircraft (AMDAR) data

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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The Domain

• 6.5km

resolution

• 37 vertical

levels

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25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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ATOVS data (1)(Advanced TIROS Operational Vertical Sounder)

Local reception:• HRPT antenna

(High Resolution Picture Transmission)

• Satellites: NOAA-15, -16(max 3 orbits/window)

• Instrument: AMSU-A(temperature)

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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ATOVS data (2)

Local pre-processing:• AAPP 1C level data• Channel selection: 7 channels like in ARPEGE

over land• Bias correction (Harris and Kelly, 2001):

- scan angle error

- 4 predictors to correct model to obs errors• inclusion to ODB (the usable data base for 3d-var)

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

7

ATOVS experiments

4 assimilation cycles using ATOVS:

Control: • 3d-var parallel suite (SYNOP + TEMP only)

• 2 using different thinning distances (120 and 80 km)

• 2 using univariate and multivariate formulation

of the B matrix for specific humidity

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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ATOVS results (1)Score comparisons: (RMSE and BIAS of 48h forecasts)• 80 km > 120km here only 80 km results• slight improvement in 850hPa geopotential (mostly neutral

results for other levels)

ATOVS control

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

9

ATOVS results (2)• mostly neutral results for temperature and wind

generally (850hPa is shown)

ATOVS control

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

10

ATOVS results (3)multivariate q

• negative impact on humidity in general

ATOVS control

initiative to try the univariate q formulation

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

11

ATOVS results (4)univariate q

ATOVS uni q control ATOVS uni q ATOVS

• but we loose some improvement on geopotential!

multivariate humidity should not be forgotten.

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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AMDAR data (1)(Aircraft Meteorological Data Reporting)

AMDAR is available

through GTS.

Pre-processing is only

the inclusion of the

raw reports into ODB

(the usable data base

for 3d-var)

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

13

AMDAR data (2)

• useful information

near the airports

(vertical sounding)

• Observations:

T, u, v

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

14

AMDAR experiments

2 assimilation cycles using AMDAR:

• 170 km thinning (like in ARPEGE)

• 50 km thinning

Control:• 3d-var parallel suite (SYNOP + TEMP only)

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

15

AMDAR results (1)Score comparisons:• 170 km > 50 km here only 170 km results

• neutrality or slight improvement for all variables (850hPa is shown)

AMDAR control

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

16

AMDAR results (2)

AMDAR control

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

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Conclusions & continuation

• Mainly neutral impact for both ATOVS and AMDAR.

Case studies of interesting situations

• How to improve:

ATOVS:– channel selection (problem with some of the used channels)

– tuning of o (softer channel selection)

AMDAR:– finer thinning (resolve problems with it)

• ATOVS & AMDAR together

_____________________________________________________________________________________

25th EWGLAM and 10th SRNWP Meetings, 6-9 October 2003, Lisbon

Gergely Bölöni, Roger Randriamampinanina, Regina Szoták, Gabriella Csima: Assimilation of ATOVS and AMDAR data in the ALADIN 3d-var system

18

Many thanks for your attention!