Continuity Salinity Science at Earth & Space Research: SVDS and Rain Lens Modeling
[27-Aug-2018] Schanze, J., Kao, H-Y., Springer, S.R., Lagerloef, G.S.E., Carey, D., and Thompson, E.J.
Presented at the 2018 Ocean Salinity Science Team and Salinity Continuity Processing Meeting
Here, we present a brief update on ongoing salinity science and validation at Earth and Space Research. With the transition from Aquarius to SMAP, it is particularly important to understand the differences in how surface salinity features are observed by these radiometers to create a continuous salinity data record spanning seven years. Furthermore, regular validation of SMAP is crucial to understand limitations and advances in the retrieval algorithms, and to assess the quality of the observations.
The recent Salinity Processes in the Upper Ocean Regional Study - 2 (SPURS-2) field program has provided a unique dataset of concurrent salinity and meteorological observations. These measurements are leveraged to inform small-scale modeling of freshwater lenses, which are prevalent features in both the intertropical convergence zone (ITCZ), monsoon areas, and high latitudes. Results from idealized high-resolution Regional Ocean Modeling System (ROMS) runs with different wind forcing reveal a strong dependence of the lens persistence time to wind forcing, with higher persistence at lower wind speeds.
In the second part, we present results of the transition from the Aquarius Validation Data System (AVDS) to the salinity validation data system (SVDS), which is designed to validate both Aquarius and SMAP products through match-ups with in situ
data. The statistics of the currently available data record of SMAP v2.1 and Aquarius v5.0 are compared by latitude band, revealing a significantly lower standard deviation of Aquarius when compared to SMAP, particularly at extra-tropical latitudes. In addition, we show how the SVDS can be used to compare results from the deployment of the salinity snake during the recent SPURS-2 field program. In a comparison of salinity snake in situ
data, SMAP v2.1, and HYCOM output, we find HYCOM to be oversmoothed. HYCOM output should thus not be used to estimate sub-footprint variability.