SMOS L2 Ocean Salinity

www.argans.co.uk

Level 2 Ocean Salinity

Status

6 October 2014

ARGANS & SMOS L2OS ESL

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SMOS L2 Ocean Salinity

www.argans.co.uk

L2OS status

• Processed all L1c v620 May & November 2011 (1700+ orbits) using tuned configuration (except not using L1 snapshot error flags)

ESL & ARGANS analysis -> TN for FAT

• Processed all L1c v620 South Pacific 01/05/2011 to 31/04/2012 (291+ orbits) using tuned configuration (except not using L1 snapshot error flags) – results follow…

• Processed all L1c v620 South Pacific 13/01/2010 to 28/02/2014 (4000+ orbits), extracting AUX_DTBXY for L1 tools long-term drift analysis (using ISAS climatology) – L1 drift presentation?

• ADFs for reprocessing & pre-reprocessing rehearsal delivered 25/09/2014Tuned configuration gives higher quality salinity than 1st reprocessing, but fewer retrievals => quality rather than quantity

OTT for reprocessing (20100601) & rehearsal (20110501 & 20111101)

• L2OS v622 & OSCOTT v622 delivery 08/10/2014, FAT 17/10/2014 (TBC)minor bug fixes, no UDP/DAP science impact…

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SMOS L2 Ocean Salinity

www.argans.co.uk

L2OS v62x PRs since v620 delivery 05/09/2014

L2OS

0092: missing AUX_CNFOSD in delivery0093: AUX_DTBXY HDR wrong data in <File_Class>0094: different (identical) XML R/W API (04_02_01 or 02) – since 20090095: missing ADFCC description of AUX_CNFOSF changes0096: confusion of 2 x L1c products with same name but different dataJoel Wesson: Num_DSR wrong in AUX_RGHNS3 HDR – since 2011ESL(JLV)/0097: corrupted A3TEC fields in AUX_DTBXY_

OSCOTT

0002: writing AUX_DTBCUR when no valid DTBXY & input DTBCUR emptyIndra(Miguel)/0004: reports with same validity start/stop if no valid DTBXY_

No impact on science products (ie UDP/DAP) since v620

v622 ready for delivery now…

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SMOS L2 Ocean Salinity

www.argans.co.uk

Major L2OS changes from v550 to v62x

• New forward model for galactic signal correction (Geometric Optics model)

• Improved galactic noise flagging

• Updated empirical roughness model 3

• Improved RFI detection & flagging

• New OTT post-processor (OSCOTT) corrects drift daily

• TEC retrieval from Stokes 3 for descending orbits (retrievals & OTT)

• Refined galactic map LUTs

• Improved measurement selection

• Bug fixes in iterative scheme exit condition, computation of TB_42.5X/Y/H/V

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SMOS L2 Ocean Salinity

www.argans.co.uk

Expected reprocessing performance• Long term drift correction

• ISAS comparisons – better RFI sorting, decreased N-S bias, better std (JB)

• Improved quality in 9 day Level 3 maps (BEC)

• L2OS metrics – better quality, less noise (MA)

• Details in SO-TN-ARG-GS-0094_L2OS_v62x_ESL_Evaluation5

SMOS L2 Ocean Salinity

www.argans.co.uk

OSCOTT monitoring L1c long-term drift

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Median snapshot error, June 2010 – February 2014 (model TB minus L1c TB in South Pacific 120-130W, 15-25S): minimal long-term drift, seasonal cycle remains.

What about salinity?...

AFFOV

SMOS L2 Ocean Salinity

www.argans.co.uk

OSCOTT impact on salinity – per orbit

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L2OS v550 DPGS OPER

SSS1 delta = retrieved – prior

South Pacific orbits, 120-130W, 15-25S, filtered by quality < 150

Operational: large oscillating bias due to monthly OTT delayed by ~24 days

First reprocessing: smaller bias due to OTT every 2 weeks with no delay

L2OS v550 REPR

SMOS L2 Ocean Salinity

www.argans.co.uk

OSCOTT impact on salinity – per orbit

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L2OS v620

L2OS v550 REPR

Second reprocessing & DPGS operational chain: smaller bias due to daily OTT

std(dSSS1_A) 0.21 psustd(dSSS1_D) 0.26 psu

First reprocessing: smaller bias due to OTT every 2 weeks with no delay

std(dSSS1_A) 0.23 psustd(dSSS1_D) 0.31 psu

SMOS L2 Ocean Salinity

www.argans.co.uk

OSCOTT impact on salinity – 9 day average

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L2OS v620

L2OS v550 REPR

Second reprocessing & DPGS operational chain: good bias tracking due to daily OTT

First reprocessing: tracking slow drift May-August, but not later

SMOS L2 Ocean Salinity

www.argans.co.uk

OSCOTT impact on salinity – 9 day average

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L2OS v620

L2OS v620 OTT region

Second reprocessing & DPGS operational chain: good bias tracking due to daily OTT

OTT region: 0-30S, 120-150W

SMOS L2 Ocean Salinity

www.argans.co.uk

What’s next…

• Contract close-outL2OS/OSCOTT delivery & FAT

Delivery of tools for L1 metrics (late!)

• Pre-reprocessing rehearsal test:first look at impact of updating AUX_DGGRFIcheck tuned configuration (now filtering L1 snapshot errors)

• Monitoring & analysis of reprocessing, update web-site

• Develop follow-on contract work plan (RFQ proposal, & tomorrow @ QWG

• Consolidate L2OS metrics

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