Surface temperature and salinity in the northern Bay of Bengal: in situ measurements compared with satellite observations and model output

Abstract

The northern Bay of Bengal (BoB) has been traditionally understudied and undersampled. Satellite and modeling products could compensate for the scarcity of in situ measurements, but this requires evaluating the accuracy of satellite and modeling products first. We present a comparison of sea surface temperature (SST) and sea surface salinity (SSS) products (satellite and model output) with 46 in situ observations in the northern BoB. We used satellite and modeled SST (daily) and SSS (weekly and daily) in this comparison. The results are as follows.(1) Both model and satellite-derived SSTs agreed well with in situ observations and with each other, with small biases (<1°C) and large correlation coefficients (r > 0.77).(2) Neither model nor satellite SSSs agreed well with in situ observations (biases > 0.5 PSU, r < 0.54).(3) Calculations of the d-index support the argument that model and satellite SSTs agreed well with in situ observations (d-index values of 0.68 and 0.65, respectively), while the model and satellite SSSs did not agree well with observations (d-index values of 0.31 and 0.40, respectively). The results suggest that additional work is needed to improve both model prediction and satellite retrieval algorithms for SSS in the northern BoB.