Variability and sensitivity of coupled mix layer-acoustic model systems

Abstract

This study is the first reported analysis of coupled mixed layer-acoustic model systems. The analysis emphasizes the performance of the combined systems rather than the acoustic or ocean models separately. Acoustic variability of the coupled model systems was studied in terms of the median detection range (MDR). Synoptic time variations of MDR as a function of figure of merit, frequency and receiver depth were analyzed during the month of May 1980 at OWS "Papa" in order to provide a better insight into the operational capabilities of model systems to accurately represent the actual ocean variability. The results of this limited analysis revealed that the model systems displayed more day-to-day acoustic (MDR) variability than did direct environmental input (BT). The capability to accurately model the thermal structure was reviewed with the following results. No significant correlation was observed between the EOTS model and the actual BT mixed layer depths while there appeared to be a strong positive correlation between the ODT model (driven by atmospheric forcing) and the BT mixed layer depths. Moreover, a possible lag of two days was observed in the EOTS model mixed layer depth relative to the observed mixed layer depth time series.