uprava.gov.hr prijma za stručno... · sss sss sss sss . sss . sss
QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum...
-
Upload
evan-kelly-turner -
Category
Documents
-
view
216 -
download
1
Transcript of QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum...
![Page 1: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/1.jpg)
QWG-12
Ocean studies (v5 reprocessed SSS)-South Pacific Maximum Salinity-North Atlantic Maximum Salinity (SPURS)-Variability of SSS: effects of rain/roughness/interpolation smoothing
Several topicsVersion 6 versus version 5
-v602 in May 2011 (land/ice contamination; ARGO colocations)-v610 in December/descending (sun?)
Ice coverageRain-Roughness effect/ 2-step algo
![Page 2: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/2.jpg)
QWG-12
Version 6 versus version 5
J. Boutin, N. Martin, X. Yin-L1v602 (land & ice contamination worse in
L1v602 than in v5.5 not shown in this presentation); colocs with ARGO.
-Sun impact on descending orbits in December with L1v610?
![Page 3: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/3.jpg)
QWG-12
Mai 2011 – L1 v602 + L2 v6 versus v5 reprocessed
Land and ice contamination worse in L1 v602!
![Page 4: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/4.jpg)
QWG-12
Mai 2011 – L1 v602 + L2 v6 versus v5 reprocessed
Far from continents (>700km), comparisons with ARGO : colocs +/-9days, +/-50km ; 10 -25 Mai 2011
![Page 5: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/5.jpg)
QWG-12
Mai 2011 – L1 v602 + L2 v6 versus v5 reprocessed
Far from continents, comparisons with ARGO : colocs +/-9days, +/-50km ; 10 -25 Mai 2011
Orbit A [45S;45N] : v5 : N= 1674 mean=-0.16 std=0.417 v6ref : N= 1674 mean=-0.13 std=0.396 v6a3tec : N= 1674 mean=-0.13 std=0.396
Orbit D [45S;45N] : v5 : N= 1605 mean= 0.04 std=0.448 v6ref : N= 1605 mean= 0.06 std=0.456 v6a3tec : N= 1605 mean=-0.05 std=0.398
Orbit A+D [45S;45N] : v5 : N= 1943 mean=-0.07 std=0.360 v6ref : N= 1943 mean=-0.05 std=0.346v6a3tec : N= 1943 mean=-0.10 std=0.321
L1 v602 gives equal or very slightly improved performance wrt v5; L2 v6a3tec improves much more
![Page 6: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/6.jpg)
QWG-12
Are descending orbits in the northern hemisphere in December less noisy in v610
than in v5 repr. ?
X. Yin, J. Boutin
Look at std(Tbsmos-Tbmodel) wrt radiometric accuracy over one descending orbit 20121217T032055_20121217T041408
between 5°N and 35°N
Flags of border, sun point and suntails are applied. The gridpoints in the FOV with number of measurements less than 30 are forced to
be blank.
![Page 7: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/7.jpg)
QWG-12
(in v5, most retrieved SSS north of 5°N in Dec are flagged December/Descending! )
![Page 8: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/8.jpg)
QWG-12
Std(Txsmos-Txmodel)/Radiometric accuracyV5 V6
V6 less noisy than v5 but still some remaining anomalous signatures
![Page 9: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/9.jpg)
QWG-12
Std(Tysmos-Tymodel)/Radiometric accuracyV5 V6
V6 less noisy than v5 but still some remaining anomalous signatures
![Page 10: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/10.jpg)
QWG-12
Std(Txsmos-Txmodel)V5 V6
V6 less noisy than v5 but still some remaining anomalous signatures
![Page 11: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/11.jpg)
QWG-12
Std(Tysmos-Tymodel)V5 V6
V6 less noisy than v5 but still some remaining anomalous signatures
![Page 12: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/12.jpg)
QWG-12
SMOS-ECMWF ice coverage wrt OSTIA ice coverage
J. Boutin, N. Martin,C. Banks
![Page 13: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/13.jpg)
QWG-12
Motivation• At the ESA LPS 2013 Chris Banks suggests that
SMOS was biased close to ice as detected by OSTIA
• In v5 (and v600), in L2OS processor threshold for ice concentration is not put to 0% but to 30%
• =>look at difference between considering a threshold=0% or 30%
• => look at difference between SMOS-ECMWF & OSTIA ice concentration
![Page 14: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/14.jpg)
QWG-12
Data & Method
• All tests are performed on 15 May 2011• All SMOS-ECMWF ice concentrations along
SMOS orbits on 15 May are averaged
![Page 15: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/15.jpg)
QWG-12
SMOS-ECMWF & OSTIA coverage around Antarctica
![Page 16: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/16.jpg)
QWG-12
SMOS-ECMWF – OSTIA ice concentration
![Page 17: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/17.jpg)
QWG-12
Zoom on some regions of 0% & 30% threshold on SMOS/ECMWF ice concentration
Ice concentration between 30% and 0% concerns often a band of ~1° in latitude or even larger; this is not negligible and from a physical point of view it is necessary to consider 0%!
![Page 18: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/18.jpg)
QWG-12
SMOS SSS close to ECMWF-SMOS ice mask (purple 0%, black 30%)
Probably due to other sortings, SMOS SSS is not retrieved very close to SMOS-ECMWF ice on 15 May asc orbits
![Page 19: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/19.jpg)
QWG-12
SMOS SSS close to ECMWF-SMOS ice mask (purple 0%, black 30%)
The southern limit of SMOS retrieval is closer to OSTIA than to ECMWF ice concentration =0%
![Page 20: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/20.jpg)
QWG-12
Conclusion
Study in progress; some strange across track biases close to ice (TBC) but it was v6!!! It would be safer to put threshold to 0% instead of 30% on percentage of ECMWF ice coverage (although it seems that other tests in L2OS already discard data within 0 and 30%)
![Page 21: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/21.jpg)
QWG-12
Rain-Roughness effect : what two-step algorithm tells us
X. Yin, J. Boutin, N. Martin
![Page 22: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/22.jpg)
QWG-12
Two-step retrieval
![Page 23: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/23.jpg)
QWG-12
![Page 24: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/24.jpg)
QWG-12
rWSOP - WSSSMIS
rWStwostep - WSSSMIS
24
In regions with large ECMWF-SSMI WS differences, 2-step retrieved SMOS WS closer to SSMI WS; 2-step method more sensitive to problems near continents and RFI regions
WSECMWF - WSSSMIS
North Eq PacEast Eq Pac
![Page 25: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/25.jpg)
QWG-12
rWSOP - WSSSMIS
rWStwostep - WSSSMIS
25
In regions with large ECMWF-SSMI WS differences, 2-step retrieved SMOS WS closer to SSMI WS; 2-step method more sensitive to problems near continents and RFI regions
WSECMWF - WSSSMIS
East Eq Pac region
![Page 26: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/26.jpg)
QWG-12
Statistics in August 2010 –Ascending orbits(EEP contains low WS that may create an additional problem)
![Page 27: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/27.jpg)
QWG-12
SMOS SSS – ARGO SSS5°N-15°N Pacific Ocean
Operational SSS Two step SSS
SMOS SSS [1cm]– ARGO SSS [5m] correlated with SSM/I rain rates (within -80mn;+60mn from SMOS passes)
Boutin et al., Ocean Science, 2013
Still strong correlation with RR when an alternative SMOS roughness correction scheme is used (poster Yin et al., 4P-117)
Method described in 4P-117
Change in roughness by raindrop: a second order effect wrt vertical stratification (account for less than 20% of observed SSSsmos-SSSargo difference)
![Page 28: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/28.jpg)
QWG-12
Conclusions
As suggested by 2-step algorithm, rain induced roughness is an order of magnitude smaller than rain-stratification effect
2-step algorithm very useful to detect peculiar roughness (not wel modelled with ECMWF WS) but very sensitive to land contamination, RFI...
![Page 29: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/29.jpg)
QWG-12
Scientific studies that used v5 reprocessed SSS
-South Pacific Maximum Salinity-North Atlantic Maximum Salinity (SPURS)-Variability of SSS: effects of rain/roughness/interpolation smoothing
![Page 30: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/30.jpg)
QWG-12
In press
Figure 1. (a) Mean 1990-2011 modelled mixed-layer salinity. The blue lines represent the Matisse Ship routes of 2010 and 2011 discussed in the main text. (b) Mean Evaporation – Precipitation (E-P) based on ERAi; units are mm/day. Overplotted as arrows are the mean modelled surface currents. The 0 isohyet is shown on both panels with a bold black solid line.
![Page 31: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/31.jpg)
QWG-12
(Hasson et al, JGR, 2013 in press)
Comparison between near-surface salinity data derived from (black line) the TSG instrument installed on board M/V Matisse and the collocated SSS: (dashed line) modelled and (dotted line) SMOS values. The Matisse salinity values were obtained during 20-27 February 2011 along the northern shipping line shown in Figure 1a.
SMOS SSS, modelled SSS and ship SSS
Model: ORCA025.L75-MRD911 run by french Drakkar group
Over 8 VOS TSG transects (averaged over 20-30km): For a collocation radius of 9 days and 50 km, std difference :Between SMOS and in-situ SSS : 0.20Between modelled and in-situ SSS : 0.26(mean biases -0.08 and 0.07, respectively)
![Page 32: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/32.jpg)
QWG-12
(Hasson et al, JGR, 2013 in press)
Mean mixed-layer salinity budgets in the high-salinity regions bounded by the 35.6, 36 and 36.4 isohalines
Salinity budget as derived from model analysis
Evaporation-Precipitation (~0.7pss yr-1) balanced by the horizontal salinity advection (~--0.35 pss yr-1) and processes occurring at the mixed layer base (~-0.35 pss yr-1).
![Page 33: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/33.jpg)
QWG-12
(Hasson et al, JGR, 2013 in press)(a) Monthly and (b) annual mean positions of the modelled 36-isohaline. On both panels the colored dots and stars show respectively the barycentre of the modelled and SMOS-derived 36 isohalines
Seasonal and interannual displacement of 36 isohalines
Model: ORCA025.L75-MRD911 run by french Drakkar group
Very consistent seasonal variation of longitudinal displacement between SMOS and modelled SSS (according to ship SSS, max of modelled SSS could be too north)
![Page 34: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/34.jpg)
QWG-12
SMOS-LOCEAN activities in SPURS region(Hernandez et al., Kolodziejczyk et al., 2013, in prep. JGR-SMOS-
AQUARIUS)
![Page 35: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/35.jpg)
QWG-12
SMOS senses mesoscale variability (≠ ISAS)(Hernandez et al., Kolodziejczyk et al., 2013, in prep. JGR)
SMOS vs TSG SSS anomaly (0.25° resol.) ISAS vs TSG SSS anomaly (0.25° resol.)
Ship data from 07/2011 to 12/2012: 14 transects
SMO
S –c
limat
o SS
S
ISAS
–cl
imat
o SS
S
TSG –climato SSS TSG –climato SSS
Once monthly biases are corrected, SMOS senses variability with a RMSE= 0.14
![Page 36: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/36.jpg)
QWG-12
SMOS and in situ salinity: rain, roughness and interpolation
effectsJ. Boutin1, N. Martin1, J.L. Vergely2, X.
Yin1, G. Reverdin1, F. Gaillard3, O. Hernandez 1, N. Reul4
1 LOCEAN/CNRS, Paris, 2 ACRI-st, Paris, 3 LPO/IFREMER, Brest, 4 LOS/IFREMER, Toulon, France
![Page 37: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/37.jpg)
QWG-12
ISAS~5m depth
~3°smoothing
SMOS1cm depth
100x100km 2
averages
ITCZ
SPCZ
Motivation:SMOS S1cm maps versus in situ S~5m maps
CATDS-CEC/LOCEAN_v2013 product
SSS August 2010 Rain Rate (SSMI)
![Page 38: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/38.jpg)
QWG-12
Outline
-Assessment of Levenberg and Marcquardt (LM) retrieved SSS error: SMOS SSS variability within 100km-1month in and out of rainy regions: comparison with SMOS SSS error predicted by LM.
-Alternative roughness retrieval: the 2-step algorithm of X.Yin =>weak effect of rain-roughness on SMOS-ARGO SSS: first order is vertical stratification
-Monthly SMOS SSS maps wrt in situ derived maps (ISAS):-differences linked to rain-stratification -differences linked to interpolation smoothing
![Page 39: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/39.jpg)
QWG-12
Data & Methods
SATELLITE
SMOS SSS
ESA v5 reprocessing
SSS at 1cm depth ; ~40km resolution or averaged (CATDS-CEC/LOCEAN_v2013 product available
at www.catds.fr) ; focus on August 2010 monthly maps
Rain Rate:
-SSM/I (RemSSS: www.ssmi.com) 0.25° resolution; SMOS SSS colocated within -80mn, +40mn
IN SITU SSS
ARGO INDIVIDUAL PROFILES
‘SSS’ between 10m and 4m depth; Colocation with SMOS within +/-5days, +/-50km CORIOLIS
GDAAC: http://www.coriolis.eu.org
ARGO + TSG OPTIMAL INTERPOLATED SSS MAPS (ISAS)
Monthly maps from In-Situ Analysis System v6 – Correlation scale ~300kmhttp://wwz.ifremer.fr/lpo/SO-Argo/Products/Global-Ocean-T-S
![Page 40: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/40.jpg)
QWG-12
Method for building SMOS SSS maps(CATDS LOCEAN_CEC_v2013)
• Monthly SSS average over 100x100km2
– weighted by each SSSj resolution (Rj) and theoretical uncertainty on retrieved SSS (ej) derived by the L.M. algorithm ( depends on NTb, dTb/dSSS,...)
• Mean theoretical error on single SMOS SSS is computed with same weights
ESSS =eSSS
e e
e
![Page 41: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/41.jpg)
QWG-12
SMOS SSS theoretical error & observed variability
Mean theoretical error on single SMOS SSS (~43km resolution): eSSS
Standard deviation of L2OS SMOS retrieved SSS over 1 month in 100x100km2: SSS
(if no natural variability, no bias on SMOS SSS, errorSSS~SSS)
![Page 42: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/42.jpg)
QWG-12
SMOS SSS theoretical error & variability:SSS - eSSS
Large SSS close to the coast (large and variable SMOS SSS biases)
750km
![Page 43: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/43.jpg)
QWG-12
SMOS SSS theoretical error & variability:SSS - eSSS
Large SSS close to the coast (large and variable SMOS SSS biases) but also in tropical regions
Influence of rain on SSS – eSSS ? Several possible causes:-natural variability (rain is an intermittent process)-rain-roughness artefact on SSS retrieval
![Page 44: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/44.jpg)
QWG-12
SMOS SSS theoretical error & variability:Correlation with rain
Tropical Pacific 5N-15NSSS – eSSS ~0.6 * RR :
- SSSvar2 ~ SSS2 - eSSS2 For RR=0.5mm/hr & eSSS=0.6 => SSS natural variability ~0.6
order of magnitude need to be further checked with in situ ground truths
SSS – eSSS versus monthly SSMI Rain Rate
![Page 45: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/45.jpg)
QWG-12
SMOS SSS – ISAS SSS
After masking areas close to continents and RFIS:SMOS SSS-ISAS SSS
Global Ocean: moy=-0.16 (std=0.36)30°S-30°N: moy=-0.18 (std=0.28)
What is the impact of a correction for rain stratification effect as seen on SSSsmos-SSSargo?
![Page 46: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/46.jpg)
QWG-12
SMOS S1cm – ARGO S~5m =fn(RR)
Zone ITCZ (Jul-Sep2010) Rain aRR+b r NSsmosA-Sargo SSMI -80mn +60mn -0,17RR-0,16 -0,49 7152Zone SPCZ (Jun10-Feb11)SsmosA-Sargo SSMI -80mn +60mn -0,22RR-0,26 -0,51 4305SsmosD-Sargo SSMI -80mn +60mn -0,19RR-0,29 -0,40 2716SsmosA-Sargo TRMM 3h before -0,15RR-0,20 -0,33 8352SsmosD-Sargo TRMM 3h before -0,16RR-0,23 -0,32 5537
SMOS S~5m ~ SMOS S1cm + 0.19 RR
Boutin et al. 2013
Region close to ITCZ Region close to SPCZ
![Page 47: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/47.jpg)
QWG-12
SSScorr-SSS SSScorr-SSSisas
Effect of Rain correction on monthly SSS A small correction (not the same color scales!!)
Without rain correction: moy=-0.16 (std=0.36)moy=-0.18 (std=0.28)
With rain correction: moy=-0.15 (std=0.36)moy=-0.17 (std=0.28)
SSSsmos – SSSisas :
Global Ocean: 30°S-30°N:
Vertical stratification of S linked to rain is not responsible for the main differences between SSSsmos-SSSisas – Influence of ISAS optimal interpolation (~300km)???
![Page 48: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/48.jpg)
QWG-12
Global: moy=-0.09 (std=0.22)
30°N-30°S: moy=-0.09 (std=0.21)
moy=-0.16 (std=0.36)
moy=-0.18 (std=0.28)
SSSsmos_like_ISAS - SSSisas SSSsmos- SSSisas
Effect of ISAS interpolation
![Page 49: QWG-12 Ocean studies (v5 reprocessed SSS) -South Pacific Maximum Salinity -North Atlantic Maximum Salinity (SPURS) -Variability of SSS: effects of rain/roughness/interpolation.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649f285503460f94c41660/html5/thumbnails/49.jpg)
QWG-12
Summary-SMOS SSS theoretical error in very good agreement with the SMOS SSS observed variability within 100x100km2 and one month, except close to continents, RFIs and in rainy regions.-In rainy regions, salinity natural variability is expected to be large (temporally, spatially and vertically):
-SMOS suggests S1cm variability due to time/space variability over one month ~0.6 for a monthly RR=0.5mm/hr. This order of magnitude should be checked in future studies with surface ground truth.
-When averaged over one month, the rain induced vertical salinity difference between 5m & 1cm is small (<0.1).
-When SMOS SSS interpolated similarly to in situ SSS : precision on monthly SMOS SSS smoothed at ~3° resolution ~0.2 between 30°N-30°S.
-