L2OS: Product performance summary v550 highlights

SMOS QWG-9, ESRIN 24-26 October 2012

L2OS: Product performance summary v550 highlights

1

The SMOS L2 OS Team


• Many presentations made on SSS retrieval issues starting at IOCP Keypoint 1, plus several validation exercises using Argo floats data

• Present: First SMOS general reprocessing has provided a coherent data set built with L1OP 5.04 and L2OS 5.50 for product performance analysis

• SMOS L2 OS Product Performance Status Report issue 2.3, October 2012 (draft under improvement):– Status of main SSS retrieval problems– Analysis of one year of SMOS salinity, 2011– User Data Product performance review– Status tables for UDP fields: grid point data, salinity, flags and quality

descriptors

SMOS L2OS performance

2


L2OS version L2OS delivery date

L2 installation date

03_10 22/10/2009 28/11/200903_11 07/01/2010 28/01/201003_12 28/01/2010 not installed03_13 09/02/2010 14/02/201003_14 26/03/2010 12/04/201003_15 14/05/2010 25/05/201003_16 21/06/2010 06/07/201003_17 22/11/2010 08/03/201105_00 27/05/2011 19/10/201105_50 17/11/2011 15/12/2011

3

SMOS L2OS performance

• L2OS operational processor history

reprocessing 2010-11

• v550 main change: double OTT (asc/desc), updated monthly (bi-weekly and centered for reprocessing)

• Other minor 500 & 550 modifications (several flags/filtering improvements, bugs fixed, new LUTs for roughness,...)

• Strong impact of L1 modifications


Issues still degrading SMOS SSS retrieval. Different degrees of improvement with the new L1 & L2 processors versions:

1. Land contamination

2. RFI

3. Unrealistic drifts: long/short TB drifts, geophysical

4. Sun tails

5. Galactic noise modelling

6. Roughness effects

7. Auxiliary data quality: wind vector, TEC, ...

3, 4, 5 impacting the spatial bias correction (OTT technique)

4

SMOS OS retrieval problems

Paul (+ Nicolas)

Paul, Joe (+Jérôme)

Jacqueline

Joe

Paul


L1 346 (with bug corrected) + L2 317 - climatology L1 504 + L2 550 - climatology

RFI

Land contaminationExpected impact of Gibbs

No flag filtering has been applied, to keep contaminated data

RFI

by C. Gabarró, ICM/SMOS-BEC5


L1 346 + L2 317 (with bug corrected) - climatology L1 504 + L2 317 - climatology

L2 550 - L2 317

6


July 2011 reprocessed

March 2011 reprocessed

Asc-desc monthly average

7


September 2011 reprocessed

November 2011 reprocessed

8

Asc-desc monthly average


H-Pol V-Pol

Pre-launch roughness models and fitted to SMOS data

Wind induced Tb at θ=32.5°from 3 models and SMOS data

Pre-launch: bad fit to ECMW wind speed sensitivity

Tuned after analysis of SMOS data: much better agreement

Clear non-linear behaviour with wind speed

H-Pol V-Pol

Pre

Post

Roughness effects

by S. Guimbard, ICM/SMOS-BEC9

SMOS QWG-9, ESRIN 24-26 October 2012 10

Roughness effects

Differences between 3 roughness models: Highly reduced after fitting to SMOS data (SSS2 is now also semi-empiric)

Yearly statistics of L3 1º x 1º monthly maps (filtering out wind >12 m/s): Global S. Pacific N. Pacific 60N-60S OTT region 45N-60Nbias STD bias STD bias STD

SSS1-SSS2 0.01 -0.02 0.02 -0.01 -0.06 0.01SSS1-SSS3 0.02 -0.03 0.03 0.00 -0.09 0.00SSS2-SSS3 0.01 -0.01 0.01 0.01 -0.03 -0.01

Variability in the SSS field due to the different roughness correction is lower than requirements (0.1 for 100 km 30 days averages)


Roughness effectsRetrieved SSS using the three roughness models implemented in v550


After filtering by Dg_quality_SSSx

Ascending orbit on 19 October 2012

Roughness effects


Product performance review

Objective: to report performance of the fields in the User Data Product

• Analysis of SSS accuracy

• Analysis of quality descriptors (flags and counters)

• Summary in status tables

• No analysis for Acard (no in situ data for validation)

• No analysis for non-retrieved parameters (SST, WS)

• No analysis for by-products (modelled TBx,y,h,v at 42.5º)


10-days/1o averaged SSS3 -12 August 2011

Zonal average SMOS-Argo

L1 v3.46 v5.04L2OS v3.17 v5.50

+0.2

- 0.2

Old processors

New processors

14by J. Martínez, ICM/SMOS-BEC

Global SSS maps


SSS accuracy: first approach

Zero order accuracy: comparison to climatology

2011 yearly statistics of 9-days L3 maps in 10ºx10º or 2ºx2º regions of contrasted conditions, different for ascending/descending

- range usually OK- anomaly within few 0.1s- important asc/desc differ.- exception: RFI areas, low

SST, high variability

Field

Region

Lat., deg

Lon., deg

SSS median ±stdev

SSS anom

SSS clim range, median ±stdev

SST med °C

WS range, median m/s

TEC

Np nor

#1 South Pacific

15°S 25 °S

120°W 130°W

36.3±0.12 -0.06 35.9-36.6 36.4±0.05

23.4

3.7-9.8 7.4

10 3.0 36.5±0.15 0.08 36 2.7

#16 South Pacific small

23°S 25 °S

118°W 120°W

36.4±0.15 0.11 36.0-36.5 36.3±0.10

23.4

1.2-11.2 6.9

10 3.1 36.6±0.31 0.26 33 2.7

#9 Intertropic. Pacific

5°N 15 °N

170°W 180°W

34.4±0.24 -0.11 34.0-34.9 34.5±0.09

27.8

4.4-11.0 7.95

6 2.9 34.7±0.16 0.19 46 2.5

#13 Intertrop. Pacific, small

3°N 5 °N

178°W 180°W

34.7±0.35 0.05 34.4-35.0 34.7±0.11

28.2

2.2-9.4 7.42

7 2.7 34.9±0.35 0.31 41 2.4

#4 Tropical Pacific, SW

10°S 24 °S

165°W 180°W

34.8±0.19 -0.22 34.4-35.8 35.2±0.17

27.8

4.2-9.7 6.4

8 2.3 34.9±0.27 -0.04 25 1.8

#6 Amazon Plume

0 12 °N

40°W 54°W

35.0±0.47 -0.59 10.6-37.8 34.9±0.46

28.1

4.1-11.1 7.4

3 1.8 35.0±0.63 -0.62 40 1.0

#8 Indian Ocean

0 10°S

60°E 70°E

34.8±0.23 -0.20 34.3-35.7 35.0±0.13

28.5

2.5-10.0 6.0

7 2.4 35.2±0.21 0.19 37 2.1

#2 Northern Pacific

45°N 55 °N

140°W 150°W

31.3±0.64 -1.26 32.3-32.9 32.6±0.07

7.9

4.7-14.9 9.0

4.7 0.7 33.2±0.58 0.52 7.5 2.8

#12 Northern Pacific, small

27°N 29 °N

145°W 147°W

35.3±0.29 -0.01 35.0-35.4 35.3±0.09

22.3

1.7-10.7 7.0

4 3.4 35.7±0.42 0.41 12 2.5

#10 Tarfaya region

20°N 30 °N

20°W 30°W

36.9±0.21 -0.09 36.2-37.4 37.0±0.04

22.7

5.0-11.0 8.0

6 2.9 37.5±0.28 0.49 19 2.3

#11 South Atlantic

40°S 50 °S

10°W 20°W

34.3±0.33 0.10 33.8-35.1 34.3±0.05

9.1

6.5-14.6 10.1

10 4.2 34.0±0.37 -0.27 11 3.4

#5 South of Tasmania

54°S 58 °S

140°E 145°E

34.5±0.54 0.64 33.8-34.0 33.9±0.03

1.8

6.1-16.4 11.1

7 4.8 34.2±0.68 0.32 12 4.1

#3 Northern Atlantic

58°N 60 °N

27°W 29°W

30.7±0.79 -4.35 35.0-35.1 35.1±0.03

8.4

3.3-18.0 10.2

3 0.9 33.3±1.28 -1.80 7 2.2

#7 Gulf of Biscay

43.5° 48 °N

1°W 6°W

31.0±0.9 -4.31 33.8-35.7 35.1±0.13 16.9

2.2-14.7 6.7

8 0.3 34.7±1.1 -0.57 7 0.2


Comparison SMOS-Argo: Proxy for absolute accuracy (with care due to Argo not samplig SSS). Only data set available for global analysis. More precise local comparisons possible (moored buoys, surface drifters)

Diagnostic sites defined in Product Performance Evaluation Plan

SSS accuracy: in situ validation

• Interesting ocean situations

• In situ sampling programs

• Expected problems


L3 binned products, filtering poor L2 grid points, wind <12 m/s, centre of swath, 2011 yearly statistics for ascending/descending/both orbits

Different analysis methodologies:• SMOS data selection (filtering by flags)• Argo data selection and interpolation to (sub)surface values• Match-up criteria• Statistical approach

BEC: 10-d/2º, monthly/1º maps, SSS3, 400 km, Argo 7.5m, box averaging

LOCEAN: 50 km/15-d, 100 km/15-d collocations, SSS1 weighted, 300 km

SSS accuracy: in situ validation


SSS accuracy: in situ validation Field Region

Lat., deg

Lon., deg

Points

RMS Mean

STD Median

IQR a, d, a+d

Global 60ºN 60ºS

all 3077 0.63 -0.19 0.60 -0.15 0.51 a 3258 0.57 -0.14 0.55 -0.08 0.42 d 3115 0.61 -0.04 0.61 0.02 0.53 b

#122 Southern Pacific

0° 30 °S

120°W 150°W

93 0.20 -0.04 0.19 -0.04 0.25 a 94 0.17 0.01 0.16 0.00 0.20 d 94 0.24 0.08 0.20 0.08 0.25 b

#124 Tropical Pacific, SW

10°S 24 °S

165°E 165°W

327 0.44 -0.16 0.40 -0.09 0.34 a 336 0.38 -0.10 0.37 -0.03 0.32 d 316 0.44 0,00 0.41 0.05 0.37 b

#125 S. of Tasmania

54°S 58 °S

140°E 145°E

2 0.70 0.37 0.35 0.43 0.48 a 2 0.65 0.62 0.19 0.59 0.27 d 2 0.70 0.57 0.34 0.55 0.49 b

#126 Equatorial Ocean

10°S 10 °N

all 606 0.48 -0.24 0.41 -0.21 0.40 a 623 0.41 -0.16 0.38 -0.11 0.34 d 604 0.42 -0.01 0.40 0.03 0.38 b

#127 Tarfaya model area

15°N 37 °N

0° 50°W

106 0.49 -0.32 0.35 -0.26 0.30 a 107 0.42 -0.19 0.36 -0.12 0.26 d

99 0.45 0.10 0.43 0.10 0.40 b #128 Amazon Plume

0 12 °N

40°W 54°W

12 0.75 -0.40 0.60 -0.28 0.64 a 12 0.70 -0.38 0.57 -0.29 0.56 d 12 0.64 -0.26 0.55 -0.13 0.49 b

#131 Southern Ocean

40°S 60°S

all 765 0.64 0.13 0.61 0.12 0.64 a 776 0.49 0.12 0.46 0.11 0.50 d 775 0.66 0.02 0.59 0.04 0.65 b

#132 Intertropic. Pacific

5°N – 15 °N

110°W 180°W

127 0.33 -0.24 0.21 -0.23 0.26 a 128 0.23 -0.13 0.18 -0.12 0.22 d 128 0.26 0.03 0.24 0.03 0.31 b

# Northern Pacific

45°N 60 °N

140°W 170°W

58 1.72 -1.06 1.32 -0.86 1.26 a 133 1.39 -0.88 1.05 -0.73 1.18 d 110 1.41 -0.8 1.12 -0.67 1.29 b

N. points

RMS Mean STD Median

IQR

68290 0.50 -0.11 0.48 -0.10 0.47 65878 0.58 0.02 0.58 0.04 0.77

134168 0.54 -0.05 0.54 -0.04 0.61 2351 0.22 -0.05 0.21 -0.06 0.27 2329 0.29 0.09 0.27 0.06 0.07 4680 0.27 0.03 0.26 0.01 0.14 7631 0.32 -0.09 0.31 -0.07 0.32 7198 0.41 0.07 0.40 0.07 0.26

14829 0.37 -0.01 0.37 -0.01 0.30 8 0.92 0.57 0.77 0.48 0.03

11 1.01 0.81 0.62 0.80 0.00 19 0.97 0.71 0.68 0.72 0.06

11738 0.39 -0.12 0.37 -0.11 0.37 10353 0.40 0.08 0.39 0.07 0.34 22091 0.39 -0.03 0.39 -0.03 0.31

3055 0.38 -0.20 0.33 -0.18 0.26 2081 0.37 0.19 0.32 0.17 0.15 5136 0.38 -0.04 0.37 -0.05 0.24

213 0.73 -0.34 0.64 -0.28 0.65 102 0.54 -0.01 0.54 0.03 0.59 315 0.67 -0.23 0.63 -0.15 0.99

16857 0.65 0.05 0.65 0.04 0.55 18415 0.73 -0.06 0.73 -0.05 0.41 35272 0.70 -0.01 0.70 0.00 0.49

3143 0.34 -0.19 0.28 -0.18 0.17 2707 0.29 0.02 0.29 0.02 0.13 5850 0.31 -0.09 0.30 -0.09 0.17

345 0.54 -0.20 0.50 -0.22 0.19 761 0.89 0.09 0.89 0.29 0.77

1106 0.80 0.00 0.80 0.10 0.93 BEC: 1º/30-d LOCEAN: 50 km/15-d

0.04-0.15±0.5-0.6

±0.2-0.3

±up to 1.3


Validation in specific regions

by J. Boutin et al., LOCEAN

Bias - 0.04 0.02

- 0.07 - 0.15

STD 0.25 0.38 0.48 0.31

Monthly 1º maps: regional comparison to Argo

19

SSS September 2011SMOS (up), Argo (bottom)

SMOS ascending orbits±300 km3-12 m/s wind


Interannual variability

SMOS : 2011-2010

ARGO : 2011-2010

Big spatial SSS 2011-2010 structures are qualitatively consistent between SMOS and ARGO

SMOS provides higher spatial resolution (+coastal and RFI errors!)

by S. Guimbard, ICM/SMOS-BEC

20


• Based on regional computations (yearly averages)

21

SSS status summary table

SSS Acard Units psu dl

Goal ±0.1

Status Not achieved yet

Range 10.0-39.7 35-62 over open ocean

Accuracy (zero order)

±0.1 (best); ±4.3 (worst)

Std = 1-2

Accuracy (in-situ)

±0.0 (best); ±0.9 (worst)

Asc/Desc ±0.1 (best); ±0.5 (worst)

±0.2 - 0.5

Time drift abs(SSSretr-SSSin-situ) evolves seasonally and differently in ascending and descending orbits (TN under preparation)

Max in March-April, min in August-September, diff≈3-4

Usability 3 (important) 1 (rarely used)

Comments


• Reported status for:– 25 control flags – 22 science flags– 19 product confidence descriptors

• Fieldsname, definition, dependencies, thresholds, status, usability, comments

example:

status: OK = implementation checkedcomments: can include evaluation of flag usefulness in terms of its impact on

filtering data to improve the quality of SSS maps. And eventually conclusions on the thresholds values.

22

Flags and descriptors

Fg_sc_rain Heavy rain suspected on gridpoint. Rain rate is above threshold Tg_max_rainfall

Contributes to Fg_ctrl_poor_geophysical and Dg_quality_SSS

Tg_max_rainfall =10 mm·h-1

OK 3 Concern raised by LOCEAN on quality of ECMWF rain information


• Analysis of reprocessed 2011 data set

• Main issues continue to be the same

• Linked to calibration, image reconstruction and modelling of geophysical variability

• L2OS team working on possible corrections

• First version of Product Performance Status Report well advanced: shaping information for users

• SMOS SSS globally not reaching mission requirements, regionally approaching them

Conclusions

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Documents

L2OS: Product performance summary v550 highlights