Figure 10.

Evaluating the accuracy of water temperature measurements from an iButton attached to the mini-Secchi disk. (a) Deployments locations of the Small Oceanographic floating Device (SOD, see photo) with iButton and mini-Secchi disk on AMT28, overlain onto a Sea Surface Temperature (SST) monthly composite of October 2018 from the MODIS-Aqua satellite [61]. (b) Results from the comparison between the housed iButton and the NIST-traceable probe at different temperatures in a recirculating water bath. The value 0.283 represents median difference in temperature (°C). (c) Along-track SST from the underway CTD system with the iButton data (corrected following removal of systematic difference of 0.283 °C) overlain. (d) Histogram of the water temperature differences between the underway CTD and iButton on the mini-Secchi disk. (e) Histogram of the water temperature differences between the profiler CTD in the top 5 m (upcast) and the iButton on the mini-Secchi disk. Two outliers are not shown on the graph (1.19 and 1.72 °C). $\overline{x}$ is the average difference, $\tilde{x}$ is the median difference, $\overline{\left|x\right|}$ is the average absolute difference, $\widetilde{\left|x\right|}$ is the median absolute difference and N is the number of samples.