1. SPURS-2 Tasks Our objectives are to: (1)Help distill and focus scientific hypotheses about the role of salinity in upperocean dynamics/air-sea interaction and the physical processes affecting its distribution and evolution, with special attention paid to precipitation dominated regimes. (2) Synthesize input from the community of scientists interested in ocean surface salinity on site selection for a SPURS-2 campaign, with the goal of providing clear guidance on the relative merits of different study regions. The merits to be considered will include scientific interest, logistical convenience (cost), risk to in situ measurement assets, and favorability for use of Aquarius and other satellite data. (3) Produce a technical report detailing the scientific rationale and approach for the SPURS-2 program.

2. Science Questions How does a fresh water source differ from a salt source? (buoyancy  mixing….) Fresh water capping issues: 1.Shallow rain puddles (meters / days) 2.Seasonal Barrier Layers (10s of meters / months) 3.Permanent Barrier Layers 1.Rain formed (ITCZ.. 2.River formed (Amazon, BoB)

3. Fresh water capping (cont) Vertical structure 1.Wind mixing 2.Thermal inversion 3.Double-diffusion 4.Internal waves 5.Solar absorption profile (river water vs ocean) 6.SST response to fluxes 7.Feed back on climate (Hurricanes (Mc Phaden et al 2012), monsoons, ENSO….)

4. Lukas and Lindstrom, 1991

5. Price, 1979. Observations of a rain-formed mixed layer

8. Fresh water capping (cont) Horizontal structure 1.Fronts 2.Currents 3.Eddies and instabilities 4.Submesoscale instabilities 5.Patchiness of rain 6.Barotropic/baroclinic responses to rain events 7.Mean barotropic/baroclinic responses to net FW flux 8.Internal waves

9. What can we learn? Space scales and structure of rain patches Ships radar CT Sensor fin on a small sail drone at 5 knots?? Impact on vertical mixing Horizontal dispersion and mixing processes Frontal instabilities

10. Costa Rican Dome Kessler 2002

12. GPCP Precip

17. SSS and S at 75m

18. T, S at 10 N 125 W

19. Tasks Ahead: May - 2014: Develop planning document for NASA and participant review July 30 – SPURS-2 Proposals due at NASA Aug 16 – Proposals due at NSF ~Oct30 SPUR-2 NASA Funding Decisions Jan 2015 NASA Funding starts Spring 2015 SPURS-2 Workshop 3 rd qtr 2015 -1 st qtr 2015 – First cruise