gergely bölöni, roger randriamampinanina, regina szoták, gabriella csima: assimilation of atovs...
TRANSCRIPT
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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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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
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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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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
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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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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)
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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 (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)
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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 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
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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 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
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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 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
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ATOVS results (3)multivariate q
• negative impact on humidity in general
ATOVS control
initiative to try the univariate q formulation
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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 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.
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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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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)
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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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AMDAR data (2)
• useful information
near the airports
(vertical sounding)
• Observations:
T, u, v
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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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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
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Many thanks for your attention!