Fig. 3: Atmospheric, lake, and river observations from March 2017 to November 2018.

a Air temperature (red), wind speed (blue), and daily liquid precipitation (black) obtained at the weather station (Fig. 1b). Hourly temperature and wind speed were filtered with 1-d (thin) and 1-week windows (thick). Grey shadings are time periods shown in Fig. 6. b Water temperature measured by mooring at the depths of 58 (blue), 139 (green), 224 (red), 309 (cyan), and 392 m (black) (Figs. 1b and 2e). c Current speeds measured by mooring at the depths of 58 (blue) and 392 m (black), and discharge of Río Grey (red) recorded at the station indicated in Fig. 1a. Currents were filtered with 1-d (thin) and 1-week windows (thick). d Water temperature distribution obtained by interpolating the data in (b). The temperature was linearly extrapolated to the regions above 58 m and below 392 m. Contour intervals are 0.2 °C. The horizontal dashed line indicates the depth of the sill shown in Figs. 1b and 2e. Markers show the depths of the temperature (●) and current/temperature sensors (■) with colors corresponding to the line colors in (b) and Fig. 6e–h.