Presented at the 2014 Ocean Sciences MeetingThe detailed salinity fronts (SFs) in the tropical Pacific are first revealed by Aquarius observations. The strongest SFs are found at the edges of freshpools on both sides of the Pacific and the south boundary of the intertropical convergence zone (ITCZ). The existences of large precipitation and shear currents are both essential for the formation of SFs. The SFs at the eastern edge of western Pacific freshpool and at the south edge of the ITCZ are found to have connections with the barrier layer (BL). In the eastern Pacific, in addition to the original ITCZ, a second branch of freshwater is observed during the boreal spring. This is the so-called "double ITCZ", and the SF can be useful to detect the variance of the double ITCZ in this region. Overall, this study presents the detailed structures and the seasonal variations of the SFs in the tropical Pacific and their relationship with the BL. The information should be useful for determining the location and the science purposes for the SPURS-2 project.