Science Meetings

What, How, and Where Can Ocean Salinity be an Indicator of the Ocean Water Cycle?
Yu, L., Jin, X., Josey, S., and Lee, T. (18-Nov-15)

Mounting evidence has suggested that ocean salinity may not be sufficient for being a surrogate rain gauge for monitoring the change of the ocean water cycle. The observed salinity signals are often formed as a result of oceanic processes (e.g. advection, mixing, and entrainment) instead of being a direct consequence of the freshwater flux changes at the ocean surface. Therefore, the use of ocean salinity for the water cycle study needs to consider two issues. One is how we can minimize the influence of ocean dynamic processes and the other is what aspects of the ocean water cycle can be constrained or checked by ocean salinity. In this study, we attempt to address the two issues by making use of 11 surface freshwater flux products, of which 9 are from reanalyses and 2 from satellite-based analyses. In particular, major discrepancies exist between the 11 products in depicting the fundamental characteristics of the ocean water cycle, such as the strength, the seasonal cycle, and the meridional extent (or width) of the net precipitation zone of the tropics and the net evaporation zones in the subtropics. To what degree that these discrepancies can be evaluated by salinity observations is examined.