Energy Export from the Tropical Pacific via the Atmosphere – a Lagrangian Perspective

The El Niño-Southern Oscillation (ENSO) is linked with energy exchange between the ocean, atmosphere and space. By using the particle dispersion model FLEXPART the atmospheric energy transport originating from the Tropical Pacific is analysed, with special focus on the connection to the Atlantic Ocean during El Niño. The Lagrangian model was filled homogeneously with five million, globally distributed particles, which were then traced forward in time from 1990 until 2016. Due to the domain-filling option used in FLEXPART, the particles represent the atmospheric mass transport. From this 26 year-long Lagrangian Reanalysis Dataset, particles between 5°S-5°N and 170°W-100°W were selected and followed both forward and backward in time. Therefore, the source regions of the energy and moisture in the Tropical Pacific can be detected, but also where they are further transported. Special focus is placed on the connection to the Atlantic Ocean. By analysing the different forms of energy (potential, - internal, - and latent energy), their transport from the Tropical Pacific into the Atlantic Ocean can be quantified. In addition, the differences between El Niño and La Niña are studied, as well as strong and weak El Niño cases.