Analysis of glider motion effect on the performance of pumped CTD: Implications for vehicle operation and data processing

With the expanding use of underwater gliders in marine observations, the quality of CTD data obtained by gliders has been of great concern over the past decades. However, current studies mainly focus on data correction methods and data quality control procedures, leaving some ambiguity regarding the influence of platform motion on the measurements of CTDs, especially for the pumped CTDs. In this study, we identified the effect of glider motion on CTD data obtained by the GPCTD through theoretical analysis and simulations, which was then validated by a field experiment. According to the results, it is recommended for underwater gliders to keep a slower platform speed and a relatively gentle operational attitude during observations. The new findings in this study are not only constructive for fine control of underwater gliders seeking to obtain high-quality CTD measurements, but also provide valuable guidance for the subsequent data processing.