1. A high-resolution Aquarius OI SSS L4 analysis: 3-year, near-global, weekly, 0.5 degree grid Oleg Melnichenko, Peter Hacker, Nikolai Maximenko, and James Potemra International Pacific Research Center, SOEST, University of Hawaii SISS Meeting 12/18/14, San Francisco, CA Link to Technical Note: http://iprc.soest.hawaii.edu/users/oleg/oisss/glb/Technical_Notes.pdf Link to product: http://iprc.soest.hawaii.edu/datadoc/oisss.php Methodology- Remove large-scale Aquarius-Argo 3-year mean spatial biases from L2 data for each beam. Optimum interpolation (OI) uses realistic correlation scales for mesoscale SSS anomalies. OI removes ascending/descending and inter-beam biases at each grid point. Result- More accurate SSS maps free from spurious structures!

2. Figure. Latitude-time distributions of the zonally averaged differences between the weekly SSS maps and the corresponding Argo buoy data for three SSS analyses: (a) standard Level-3 product without bias correction; (b) standard Level-3 SSS product with SST-dependent bias correction; and (c) OI SSS analysis of this paper. Units are psu. Error statistics were computed by comparing Argo buoy observations for a given week with SSS values at the same locations obtained by interpolation of the corresponding SSS maps. The zonally averaged biases were computed by averaging these statistics over 5-degree latitude bands. Latitude-time distributions of zonally averaged differences between weekly SSS maps and Argo data v3 standard v3 SST bias cor. OI SSS

3. Figure (a) Weekly mean differences and (b) RMSD between Argo buoy observations and three Aquarius SSS analyses: OI SSS (red), and two standard Level-3 SSS products provided by ADPS – with (blue) and without (black) bias correction. Error statistics were computed globally by comparing Argo buoy observations for a given week with SSS values at the same locations obtained by interpolation of the corresponding SSS maps. Weekly mean differences and RMSD between Argo and 3 SSS analyses OI SSS (red) ADPS v3.0 SSS: SST bias correction (blue) Standard product (black) Note reduced annual cycle bias in OI SSS product.

4. Aquarius OI SSS in the eastern tropical Pacific (a) 1-7 October 2011, (b) 10-16 December 2011, (c) 19-25 February 2012, (d) 22-28 April 2012, (e) 1-7 July 2012, and (f-j) the corresponding gradient fields. Contours are 34 psu (blue), 33 psu (cyan), and 32 psu (red) isohalines. Conclusion- Argo still provides large-scale calibration at scales >1000 km. Aquarius provides space/time SSS structure and variability at scales < 1000 km and weekly.

5. Backup slides follow

6. Figure. Mean spatial bias correction fields for Aquarius ascending (left) and descending (right) data; beam 1 (top), beam 2 (center), beam 3 (bottom); in monthly, 4x4 degree spatial bins on a 2-degree global grid. 2-year Mean Spatial Bias Fields for Aquarius Data

7. Figure. Estimated RMS error (psu) for the OI SSS analysis computed in 8-degree bins from the differences between weekly SSS maps and the corresponding Argo buoy observations for the period from September 2011 through March 2014. Estimated RMS error (differences) for the OI SSS analysis