A coastal acoustic tomography experiment in the Qiongzhou Strait

摘要

An experiment for synchronous mapping of current velocity (VCAT) and temperature (TCAT) distributions was successfully carried out using four coastal acoustic tomography (CAT) systems, from March 17 to April 1, 2013, in the Qiongzhou Strait, China. During the CAT observation period, shipboard acoustic Doppler current profiler (ADCP) surveys were also performed to observe the current velocity (VADCP) and temperature (TADCP) for the purpose of comparison with the CAT data. Position offsets, including a long-time averaged offset and a short-period fluctuation offset, were corrected for temperature estimation. The horizontal distribution of VCAT and TCAT was reconstructed by an inverse technique using the CAT data. VCAT was nearly parallel to the strait while TCAT was higher in the southern area than in the northern area. During the whole observation period, TCAT gradually increased by approximately 2°C, indicating seasonal warming. VCAT was in good agreement with VADCP, while the root-mean-square differences (RMSDs) between VCAT and VADCP for eastward and northward velocities were 0.10 m/s and 0.08 m/s, respectively. TCAT was in approximate agreement with TADCP, with an RMSD of 0.30°C.