Oceanography The Official Magazine of
The Oceanography Society
Volume 32 Issue 02

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Volume 32, No. 2
Pages 76 - 85

Capturing Fresh Layers with the Surface Salinity Profiler

Kyla Drushka William E. AsherAndrew T. JessupElizabeth J. ThompsonSuneil IyerDan Clark
Article Abstract

During the second Salinity Processes in the Upper-ocean Regional Study (SPURS-2) field experiments in 2016 and 2017 in the eastern tropical Pacific Ocean, the surface salinity profiler (SSP) measured temperature and salinity profiles in the upper 1.1 m of the ocean. The SSP captured the response of the ocean surface to 35 rain events, providing insight into the generation and evolution of rain-formed fresh layers. This paper describes the measurements made with the SSP during SPURS-2 and quantifies the fresh layers in terms of their vertical salinity gradients between 0.05 m and 1.1 m, ∆S1.1–0.05m. For the 35 rain events sampled with the SSP in 2016 and 2017, the maximum value of ∆S1.1–0.05m is well correlated with the accumulated rainfall. The maximum value of ∆S1.1–0.05m is shown to be linearly proportional to the maximum rain rate and inversely proportional to the wind speed. This wind speed-dependent relationship shows a high degree of scatter, reflecting that the vertical salinity gradient formed during any individual rain event depends on the complex interaction between the local ocean dynamics and the highly variable forcing from rain and wind.


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