OBSERVATIONS OF LARGE-SCALE RAINFALL, WIND, AND SEA SURFACE SALINITY VARIABILITY IN THE EASTERN TROPICAL PACIFIC

• Published in: Oceanography (Washington, D.C.) D.C.), 2019-06, Vol.32 (2), p.42-49
• Main Authors: Riser, Stephen C., Yang, Jie, Drucker, Robert
• Format: Article
• Language: English
• Subjects: Anomalies; Atmospheric convection; Convergence zones; Dolphins & porpoises; Fresh water; Intertropical convergence zone; Mixed layer; Moorings; Ocean currents; Oceans; Precipitation; Rain; Rainfall; Salinity; Salinity data; Sea surface; Seas; SPECIAL ISSUE ON SPURS-2: SALINITY PROCESSES IN THE UPPER-OCEAN REGIONAL STUDY 2; Storms; Surface salinity; Surface water; Tropical climate; Tropical regions; Variability; Wind speed; Wind velocity
• ISSN: 1042-8275; 2377-617X
• DOI: 10.5670/oceanog.2019.211

We examine profiling float-based measurements of rainfall, wind speed, and near-surface salinity in the eastern tropical Pacific Ocean collected during the SPURS-2 field program. The data show large-scale meridional and zonal variability in these quantities, with considerable variability near the Intertropical Convergence Zone (ITCZ). The eastern tropical Pacific data show strong, intermittent, near-surface, low-salinity events driven by rainfall along the ITCZ that generally do not occur elsewhere in the tropical Pacific. The float salinity data suggest that low-salinity surface water can be entrained 50 m or more into the mixed layer from mid-summer to early in the following calendar year, although the annual periods of strong wind and high precipitation do not coincide. Many of the low-salinity anomalies observed during the SPURS-2 program appear to result from strong, transient storms generated by atmospheric convection along the ITCZ that move across the region.