Presented at the 2014 Aquarius/SAC-D Science Team MeetingMonthly barrier layer thickness (BLT) estimates are derived from satellite-derived salinity using a multilinear regression model (MRM) within the Indian Ocean. Sea surface salinity (SSS) from the recently launched Soil Moisture and Ocean Salinity (SMOS) and Aquarius salinity missions are utilized to estimate the BLT. The MRM derived BLT estimates are compared to gridded Argo and Hybrid Coordinate Ocean Model (HYCOM) BLTs. It is shown that different mechanisms are important for sustaining the BLT variability in each of the selected regions in the Indian Ocean. Sensitivity tests show that sea surface salinity is the primary driver of the BLT within the MRM. Results suggest that salinity measurements obtained from Aquarius and SMOS can be useful for tracking and predicting the BLT in the Indian Ocean. BLT estimations using HYCOM simulations display large errors that are related to model layer structure and the selected BLT methodology. The formation of a Barrier Layer can lead to possible feedbacks that impact the atmospheric component of the Madden-Julian Oscillation (MJO), the Arabian Sea mini warm pool and the Indian Ocean Dipole.