摘要
Argo floats are flee-moving floats that report vertical profiles of salinity, temperature and pressure at regular time intervals. These floats give good measurements of temperature and pressure, but salinity measurements may show significant sensor drifting with time. It is found that sensor drifting with time is not purely linear as presupposed by Wong （2003）. A new method is developed to calibrate conductivity data measured by Argo floats. In this method, Wong＇s objective analysis method was adopted to estimate the background climatological salinity field on potential temperature surfaces from nearby historical data in WOD01. Furthermore, temperature and time factors are taken into account, and stepwise regression was used for a time-varying or temperature-varying slope in potential conductivity space to correct the drifting in these profiling float salinity data. The result shows salinity errors using this method are smaller than that of Wong＇s method, the quantitative and qualitative analysis of the conductivity sensor can be carded out with our method.
Argo floats are free-moving floats that report vertical profiles of salinity, temperature and pressure at regular time intervals. These floats give good measurements of temperature and pressure, but salinity measurements may show significant sensor drifting with time. It is found that sensor drifting with time is not purely linear as presupposed by Wong (2003). A new method is developed to calibrate con- ductivity data measured by Argo floats. In this method, Wong’s objective analysis method was adopted to estimate the background climatological salinity field on potential temperature surfaces from nearby his- torical data in WOD01. Furthermore, temperature and time factors are taken into account, and stepwise regression was used for a time-varying or temperature-varying slope in potential conductivity space to correct the drifting in these profiling float salinity data. The result shows salinity errors using this method are smaller than that of Wong’s method, the quantitative and qualitative analysis of the conductivity sen- sor can be carried out with our method.
基金
This project is supported by NSFC (No. 40376010), and also supported by SOA, China.
