Science Meetings

Analysing the Recent Signature of ENSO In the Tropical Pacific Using In Situ, SMOS and Model Salinity Data
Hasson, A., Delcroix, T., Boutin, J., Hernandez, O., Martin, N., Alory, G., and Dussin, R. (17-Apr-13)

The tropical Pacific Ocean has been in a La Niña phase from mid 2010 to early 2012. In this presentation, we will describe and analyze the well-marked signature of this ENSO phase, using a combination of in situ, SMOS- and model-derived sea surface salinity products. The in situ data include high-resolution voluntary observing ship TSG measurements and gridded SSS products. We use a newly derived SMOS product (based on ESA L2 v5.5). The model outputs are from a validated Drakkar eddy-permitting forced simulation in which all mixed-layer salinity budget terms are computed at each time-step. Comparisons of all near-surface salinity products will be presented first and discussed, focusing on SMOS ability to capture small-scale to basin wide features. The observed basin-scale La Niña SSS signal from SMOS will then be compared to historical La Niña events as represented by irregularly distributed in-situ data. It will be shown, in particular, that an unusual strong bi-polar anomaly has been captured by SMOS in the western Pacific. This anomaly will be described and discussed using all datasets and processes at work will be quantified with the model.