SMOS-BEC – Barcelona (Spain)

Assessment of impact of new ECMWF cycle 38r2

BEC team

SMOS Barcelona Expert CentrePg. Marítim de la Barceloneta 37-49, Barcelona SPAINE-mail: smos-bec@icm.csic.esURL: www.smos-bec.icm.csic.es

SMOS-BEC 2

objectives

• Analysis on the impact of using old version of ECMWF products vs new version (cycle 38r2 )

• ARGANS processed 100 orbits with new ECMWF.

• Comparison has been performed with new data vs DPGS data from 20130414 to 20130417

• Compute differences at SSS L2 at ASC/DES .

• Compute errors of SMOS L2 versus ARGO floats.

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Meteorological contents of the new cycle:•Number of vertical levels increased from 91 to 137 •Revised background error variances at 137 levels based on IFS cycle 38r1.• Revised EDA calibration and filtering for 137 levels.• Model error cycling in stratosphere switched off.• Modification of surface drag.• Modified test parcel entrainment in boundary layer and shallow convection.• Adjustment of non-orographic gravity wave drag to be consistent with System-4.• Oxygen absorption correction.• Revision of Sea-ice/SST quality control over the Caspian Sea.

Cycles comparison from ECMWF webpage

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Impact: •Meteorological impact of the new cycle: IFS cycle 38r2 increases the vertical resolution of the model throughout the troposphere and stratosphere. It enables a better representation of physical processes, clouds, inversions and vertically propagating gravity waves, for example.

•Weather parameters: For precipitation and temperature the overall conclusion is a slight improvement in the extra-tropics and a slight degradation in the tropics. The scores for 10m wind show neutral to slightly positive impact both in extra-tropics and tropics. There is an overall slight reduction of wind speed, most notable in Europe at 12 UTC.

Cycles comparison from ECMWF webpage

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SSS3 NEW_ECMWF – OLD_ECMWF

Max dif : 23 psu !!!

Large differences in the Antarctic current region ->maybe due to WS

1-1

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SSS3 NEW_ECMWF – OLD_ECMWF

1-1

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Comparison vs ARGO floats

NEW ECMWFASCENDINGSMOS- ARGO

OLD ECMWFASCENDINGSMOS- ARGO

+/- 5 days+/- 50 km

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NEW ECMWFASCENDINGSMOS- ARGO

OLD ECMWFASCENDINGSMOS- ARGO

Comparison vs ARGO floats

+/- 5 days+/- 50 km

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NEW ECMWFASCENDINGSMOS- ARGO

OLD ECMWFASCENDINGSMOS- ARGO

Comparison vs ARGO floatsV

LATITUDE LATITUDE

+/- 5 days+/- 50 km

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Comparison vs ARGO floats

NEW ECMWFASCENDINGSMOS- ARGO

OLD ECMWFASCENDINGSMOS- ARGO

LATITUDE LATITUDE

+/- 5 days+/- 50 km

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Comparison vs ARGO floats - region [-40S, -60S]

region [-40S, -60S]

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CONCLUSIONS

• Most evident effects are observed near the poles, in particular near Antarctica.

• Comparisons between SSS L2 vs ARGO show a very small improvement with the new ECWMF cycle.

• Mean (SSS-ARGO) ~ 0.01• Std (SSS-ARGO) ~ 0.003

• Higher improvements are observed bellow -40ºS (Std (SSS-ARGO) ~ 0.01).

• With 3 days of data it is not recommended to perform analysis with L3 maps .