Interannual Variability of the Spring Wyrtki Jet

Abstract:

Features of the interannual variability of the spring Wyrtki Jet in the tropical Indian Ocean are revealed using observation data and model output. The results show that the jet has significant interannual variation, which has a significant correlation with winter El Niño Modoki index . During spring after an El Niño (La Niña) Modokievent, the Wyrtki Jet has a positive (negative) anomaly, forced by a westerly (easterly) wind anomaly. The result of a linear-continuously stratified model shows that the first two baroclinic modes explain most of the interannual variability of the spring Wyrtki Jet and that the third to fifth modes together account for approximately 30%. Surface wind anomalies in the tropical Indian Ocean is related to the Walker circulation anomaly associated with Niño Modoki.The interannual variability of the spring Wyrtki Jet has an evident impact on sea surface salinity transport during the onset phase of the summer monsoon in the Indian Ocean.