Incoming and reflected shortwave radiation were also measured ̴ 10 cm above the water surface with two pyranometers (LP02, Hukseflux, Delft, The Netherlands). To estimate the incoming shortwave radiation at the water surface, before the experiments began, one pyranometer was located at the water surface while the other one was located ̴ 10 cm above it.
In this way, it was determined that 62.5% of the measured shortwave radiation at ̴ 10 cm above the water surface reached the water surface itself. Electrical conductivity (EC) was used as a surrogate measurement for salt concentration. Electrical conductivity in the solar pond was measured at ten different depths using EC electrodes with automatic temperature compensation (SK23T, Van London-pHoenix Company, Houston,TX).
Temperature within the pond was measured using a vertical high-resolution DTS system (Fig. 1a).
This DTS system measures temperature each 1.1 cm from ̴ 20 cm above the water surface to a depth of ̴ 95 cm, achieving a temperature resolution of less than 0.04 ̊C. All data were collected at 5-min intervals.
Complete details on the pond’s instrumentation and DTS system are presented elsewhere [31,32].