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SMOS L2 Ocean Salinity

Level 2 Ocean Salinity

21-22 February, 2011

ARGANS & L2OS ESL

Tools for monitoring time drifts in SMOS L2OS parameters over selected ocean regions

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SMOS L2 Ocean Salinity

Aim – to create a tool (set of scripts) for monitoring SMOS data for pre-defined regions of interest, in particular – to observe time drifts, seasonal variations of the parameters; at first stages – maybe to help identifying L1 and instrumental problems causing drift in L2OS parameters.

The results are supposed to be derived from SMOS UDP/DAP product, processed automatically, in real time (as the products appear) or post-processed;

The results should be ultimately suitable for web access, similar to current ARGANS web interface to DPGS processed SMOS DAP products.

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SMOS L2 Ocean Salinity

Regions of Interest

• SouthernPacific;• NorthAtlantic;• TropicalPacificSW;• SouthOfTasmania;• EquatorialOcean;• TarfayaModelregion;• AmazonPlume;• GulfOfBiscay;• MediterranianSea;• SouthernOcean;• IntertropicalPacific;• Spanish-IEO_Mooring;

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SMOS L2 Ocean Salinity

Model_1 retrieving WSn instead of UN10 and VN10

• Contents

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SMOS L2 Ocean Salinity

List of geophysical parameters to monitor

• Roughness 1: SSS, Sigma_SSS, SST, Sigma_SST, UN10, Sigma_UN10, VN10, Sigma_VN10, TEC, Sigma_TEC;

• Roughness 2: SSS, Sigma_SSS, SST, Sigma_SST, TEC, Sigma_TEC, Uwav (L20S_3.16 and lower) , Sigma_Uwav (L20S_3.16 and

lower), WSn (L20S_3.17 and higher), Sigma_WSn (L20S_3.17 and higher), omega, Sigma_omega, phi_wsn, Sigma_phi_wsn;

• Roughness 3: SSS, Sigma_SSS, TEC, Sigma_TEC, WSn, Sigma_WSn, HS, Sigma_HS, phi_wsn (L20S_3.17 and higher),

Sigma_phi_wsn (L20S_3.17 and higher);• Cardioid: Acard, Sigma_Acard, SST, Sigma_SST;

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SMOS L2 Ocean Salinity

Statistical output

• Min;• Max;• Mean;• Median;• Stdev;• Kurtosis;• Skew;

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SMOS L2 Ocean Salinity

Selection algorithm• For each day in specified range (say, from 15/07/2010 to 31/12/2010)

-identify list of orbits within +/- n days, say n=3;-exclude from the list the orbits with wrong asc/desc and full/dual pol;-exclude orbits not having a point(s) in pre-defined Lat/Lon box

• For each half-orbit from the list reduced according to the algorithm above-read UDP and DAP products;-exclude -999 marked points;-exclude points at the X-swath edges (say beyond +/-300 km band);-exclude points not satisfying defined UDP flag filters;

• For all the points selected above, calculate statistics listed on the previous page, for each field on the page 6, plot histogram and store statistics in a file corresponding the central day of this 2*n sampling;

• Combine statistics for each day into time line curves;

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SMOS L2 Ocean Salinity

Output of the exercise• N folders (corresponding to N days of observation) containing set of

histograms (examples on the next page) suitable for animation to watch day-by-day changes in long-term trends for specified parameters;

• N folders (corresponding to N days of observation) containing set of text files with individual statistics for the time period centred around the day of observation

• Set of time curves with dates for X-axis and one of the statistic characteristics – for Y-axis, say, mean, median, kurtosis etc. Mean and median curves are supplied by errorbars corresponding to stdev values; separate curves are produced for (a) not filtered GP sets, (b) filtered by Xswath location and (c) filtered by UDP quality flags; Kurtosis and Skew curves are plotted without errorbars but combined into triplets non-filtered/Xswath-filtered/UDP-filtered;

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SMOS L2 Ocean Salinity

Examples

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SMOS L2 Ocean SalinityExamples of histograms

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SMOS L2 Ocean Salinity

S/Pacif asc orbs 2010_10_21 3 days,148102,66213,-30.0,0.0,-150.0,-120.0,SSS,2 min, max, mean, median, std, skew, kurtosis 34.041, 39.22, 36.584, 36.572, 0.6754, 0.07864, -0.18186 # in-box, filtered, x-swath selected

######################## --STATISTICS EXTRA-- ################################################ 33.705, 39.22, 36.588, 36.575, 0.6749, 0.07184, -0.17542 # in-box, NO filt, x-swath select 28.934, 43.546, 36.605, 36.585, 1.02, 0.042553, 2.4468 # in-box, NO filt, NO x-swath sel

### Total number of processed GP's in selected orbits: 1657202### Number of GP's after removing '-999': 1057173### Number of GP's in the box (no filters): 148102### Number of GP's in the box, selected over x-swath: 75810### Number of GP's in the box, filtered: 66213

# $BOX COORDINATES$ ####### South: -30.000000###### North: 0.000000###### West: -150.000000###### East: -120.000000

# $OUTPUT$ ####### Field: SSS###### Roughness Model: 2###### Anomaly: NO

# $X-swath FILTER$ 300.000000 km #

# $UDP FILTERS$ # -Fg_ctrl_sigma = 0 -Fg_ctrl_chi2 = 0 -Fg_ctrl_chi2_P = 0 -Fg_ctrl_marq = 0 -Fg_ctrl_valid = 1 -Fg_ctrl_reach_maxiter = 0

# $ORBITS$ #/mnt/satabeast3/smos/data/2010/10/18/SM_OPER_MIR_OSDAP2_20101018T140029_20101018T145431_316_001_1, A/mnt/satabeast3/smos/data/2010/10/18/SM_OPER_MIR_OSDAP2_20101018T154034_20101018T163433_316_001_1, A/mnt/satabeast3/smos/data/2010/10/22/SM_OPER_MIR_OSDAP2_20101022T162504_20101022T171858_316_001_1, A/mnt/satabeast3/smos/data/2010/10/22/SM_OPER_MIR_OSDAP2_20101022T144455_20101022T153854_316_001_1, A/mnt/satabeast3/smos/data/2010/10/20/SM_OPER_MIR_OSDAP2_20101020T160246_20101020T165647_316_001_1, A/mnt/satabeast3/smos/data/2010/10/20/SM_OPER_MIR_OSDAP2_20101020T142241_20101020T151642_316_001_1, A/mnt/satabeast3/smos/data/2010/10/19/SM_OPER_MIR_OSDAP2_20101019T132133_20101019T141534_316_001_1, A/mnt/satabeast3/smos/data/2010/10/19/SM_OPER_MIR_OSDAP2_20101019T150137_20101019T155539_316_001_1, A/mnt/satabeast3/smos/data/2010/10/21/SM_OPER_MIR_OSDAP2_20101021T152349_20101021T161750_316_001_1, A/mnt/satabeast3/smos/data/2010/10/21/SM_OPER_MIR_OSDAP2_20101021T134346_20101021T143745_316_001_1, A/mnt/satabeast3/smos/data/2010/10/23/SM_OPER_MIR_OSDAP2_20101023T140558_20101023T145957_316_001_1, A/mnt/satabeast3/smos/data/2010/10/23/SM_OPER_MIR_OSDAP2_20101023T154603_20101023T164002_316_001_1, A

Example of stat file

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SMOS L2 Ocean SalinityExamples of timelines, different types of filtering

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SMOS L2 Ocean SalinitySub-areas of SouthernPacific

30S - 0

20S – 10S

25S – 20S

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SMOS L2 Ocean SalinityExamples of timelines

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SMOS L2 Ocean Salinity

Examples of timelinesm

/s

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SMOS L2 Ocean Salinity

Summary• We have selected a way and prepare a set of tools/scripts for statistical

monitoring of retrieved SMOS parameters for selected Ocean areas;• We are trying to identify and test proper statistical characteristics

(mean/median/kurtosis etc);• We are working on optimal filtering criteria; one preliminary conclusion –

from statistical point of view, Xswath filtering does most of the job, comparing to other types of filtering;