Progress Meeting #27, April 2015, Barcelona SPAIN T3.2 Retrieval algorithm Estrella Olmedo BEC team SMOS Barcelona Expert Centre Pg. Marítim de la Barceloneta 37-49, Barcelona SPAIN URL:

, Barcelona SPAIN 1.Work plan progress 2.General overview of our internal processing chain 3.Levenberg-Marquardt 4.Single incidence angle retrieval 2 / 38 Contents

, Barcelona SPAIN 1. Work plan progress 3 / 38

, Barcelona SPAIN 4 / 38 Work plan and progress JANFEBMARAPRMAYJUNJULAUGSEPOCT During this period, we have updated, implemented and tested software to be ready for the different simulations to be done in this task TASK 3.2 RETRIEVAL ALGORITHM: Alternatives for the retrieval: T3.2.1 Test of various L2OS configurations for retrieving SSS T3.2.2 Two-step retrieval T3.2.3 Monte Carlo approaches

, Barcelona SPAIN 2. General overview of our internal processing chain 5 / 38

, Barcelona SPAIN 6 / 38 General overview L0 MTS: TB computation Compute OTT Tb geo- localization and OTT correction Computation of forward model and download measured TBs at BOA SSS and WSN retrieval L3/L4 map computation ARGO validation BEC internal processing chain ESA input L1B Change format L2 ARGANS input BEC output ARGO statistics L3/L4 maps SSS semi-orbits and SSS distributions

, Barcelona SPAIN SSS and WSN retrieval This task corresponds to this point General overview

, Barcelona SPAIN 8 / 38 General overview Retrieve SSS only One SSS per measurement Retrieve SSS and WSN One SSS per grid point One SSS and one WSN per grid point Levenberg- Marquardt 1-D Newton method First Stokes DUAL FULL BOA ARF Constraints No Constraints

, Barcelona SPAIN 3. Levenberg-Marquardt 9 / 38

, Barcelona SPAIN We have implemented a Levenberg-Marquardt algorithm that allows different configurations Using the same input data and running L2PP and L2BEC with the same configuration, the resulting salinities are the same The complete processing chain is different: Different grid for snapshots Different grid for semi-orbits Etc.. 10 / 38 Levenberg Marquardt

, Barcelona SPAIN 11 / 38 Levenberg-Marquardt TEC is fixed Very simple pre-filtering conditions are implemented so far The post-filtering criteria is not yet analyzed The program allows also retrieving in BOA

, Barcelona SPAIN 12 / 38 Levenberg Marquardt: preliminary tests

, Barcelona SPAIN ARGO comparison ARGO GlobalTropicNPacTarfZ122Z124Z126Z131Z132OTT L2PPMean Std Nbuoy L2BECMean Std Nbuoy / 38

, Barcelona SPAIN 4. Single incidence angle retrieval 14 / 38

, Barcelona SPAIN Single incidence angle retrieval: Approach The minimum of each one of these parabolas represents the salinity measured by SMOS at that point for the corresponding incidence angle We compute this minimum with a Newton method. 15 / 38

, Barcelona SPAIN We consider now 7 consecutive 9-days maps in June We selected 16 points on the ocean. At each cell of 0.25x0.25 degrees we plot the distribution of the minima of last equation that have been accumulated in the 9 days. We only consider those minima between 0 and 50 psu We differentiate between the measurements provided by ascending orbits only; descending orbits only; and both together. We look at the shape of the salinity distributions at those points and the temporal evolution of them Single incidence angle retrieval: Histograms 16 / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Salinity distributions: 9-day map starting from / 38

, Barcelona SPAIN Can we use this information for filtering “bad” measurements? We compute joint histograms depending on the incidence angle and the distance to the center of the swath We are working in different ways of using this information for improving the retrieval Single incidence angle retrieval: Filter definition 24 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 25 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 26 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 27 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 28 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 29 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 30 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 31 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 32 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 33 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 34 / 38

, Barcelona SPAIN Single incidence angle retrieval: Joint histograms 35 / 38

, Barcelona SPAIN Conclusions & future work 36 / 38 We have set up an internal chain, in order to control de retrieval process and test different retrieval strategies L2BEC is now capable to ingest data from diverse sources and different formats, and provide results similar to those of L2PP We have implemented single-angle retrievals, which provides us L3 statistics of the quality of retrieved salinities We have used the L3 histograms to study the influence of the across- track distance to the center of the swath and incidence angle, and to propose new filtering schemes accordingly.