www.argans.co.uk smos l2 ocean salinity level 2 ocean salinity 13-14 september 2010 argans &...
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SMOS L2 Ocean Salinity
Level 2 Ocean Salinity
13-14 September 2010
ARGANS & L2OS ESL
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SMOS L2 Ocean Salinity
• Wind speed retrieval in Model 1 without retrieving wind direction;• Dual from Full versus Full from Full ;• EAFFOV versus AFFOV versus small xi-eta;• Increasing threshold for valid number of measurements;• Appendix;
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SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
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SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
• Contents
www.argans.co.uk
SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
www.argans.co.uk
SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
• Contents
www.argans.co.uk
SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
• Contents
www.argans.co.uk
SMOS L2 Ocean Salinity
Model_1 retrieving WSn instead of UN10 and VN10
• Better rate of successful retrievals for the modification of Roughness Model 1 not retrieving wind direction;
• Much better convergence for the model with fixed wind direction;• Model 1 with fixed wind direction slightly better correlates with Model 2;• Retrieved Wind Speed for Model 1 with variable wind direction closer to
ECMWF initial data;• Recommend using Model 1 with fixed wind direction
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SMOS L2 Ocean Salinity
Dual from Full versus Full from Full
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SMOS L2 Ocean Salinity
Dual from Full versus Full from Full
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SMOS L2 Ocean Salinity
Dual from Full versus Full from Full
• Contents
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SMOS L2 Ocean Salinity
Dual from Full versus Full from Full
• More successful retrievals for Full-from-Full (FF): 74% instead of 69 %;• Better convergence for FF; there are more points failed to reach
convergence for DF;• Better chi2 results for FF;• TEC retrieval for FF has lower cross-track bias;
• Recommend using Full Pol from Full Pol rather than Dual Pol from Full Pol;
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SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
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SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
• Contents
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SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
#GP: 64790, 40733, 34467
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SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
www.argans.co.uk
SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
• Contents
www.argans.co.uk
SMOS L2 Ocean Salinity
EAFFOV vs AFFOV vs small xi-eta
• Reducing field of view decreases edge effects but does not eliminate them completely;
• Changing field of view does not affect significantly grid point distribution against chi2;
• Reducing field of view improves chi2 values, in particularly near the edges, but the edge effect is still well seen;
• Recommend not using AFFOV or xieta reduced instead of EAFFOV;
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SMOS L2 Ocean Salinity
Increasing threshold for valid number of measurements
Extended AFFOVThreshold: 16(“min”); 30 (“low”); 50; 75
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SMOS L2 Ocean Salinity
Increasing threshold for valid number of measurements
Extended AFFOVThreshold: 16(“min”); 30 (“low”); 50; 75
www.argans.co.uk
SMOS L2 Ocean Salinity
Increasing threshold for valid number of measurements
AFFOVThreshold: 16(“min”); 30 (“low”); 50; 75
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SMOS L2 Ocean Salinity
Increasing threshold for valid number of measurements
• Increasing threshold Tg_num_meas_valid sharply improves quality of results: edge effects and East-West bias are practically eliminated with a proper threshold;
• Increasing Tg_num_meas_valid reduces amount of available gridpoints, especially after the threshold exceeds 80-100; compromise value of the threshold should be selected, about 50-60;
• Effect of increasing Tg_num_meas_valid is much stronger than redaction of the field of view, from the point of reducing biases and edge effects; if we have to use FOV reduction, it could be more efficiently used in combination with increased Tg_num_meas_valid;
• Recommend increasing Tg_num_meas_valid initially to 50;
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SMOS L2 Ocean Salinity
Appendix
All pictures in this presentation are apparently affected/contaminated by sun that is illustrated on this slide; some results look more affected than the others – in most cases this is defined only by the colour scale used;
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