Temperature and conductivity profiles from Toolik Lake, Alaska, during winter 2023-2024.

Conductivity, temperature, depth (CTD) profiles were obtained during winter 2023-2024 using a free falling YSI Castaway profiler with resolution and accuracy of temperature 0.01oC and +0.05oC respectively and of specific conductance 1 µS cm-1 and 0.25% + 5 µS cm-1, respectively. Sampling is at 5 Hz with data averaged in 30 cm bins. The data are used to describe the structure of temperature, specific conductance, and density in an ice-covered lake and to calculate the likelihood of double diffusive convection. Data here were taken at 4 m, 10m and 15 m sites in November 2023 and monthly in 2024 at either nearby 15 or 24 m deep sites while the lake remained ice-covered. The ten meter deep site has latitude and longitude 68.62730, -149.60248, the four meter deep site is 68.63282, -149.59967, the 15 meter deep site is 68.62962, -149.61127, and the ~24 m deep site is 68.629080, -149.613867.

2023-2024年冬季，我们使用自由下落式YSI Castaway型剖面仪采集了温盐深（Conductivity Temperature Depth, CTD）剖面数据。该仪器的性能参数如下：温度分辨率为0.01℃，准确度为+0.05℃；比电导率分辨率为1 μS·cm⁻¹，准确度为0.25%读数+5 μS·cm⁻¹。采样频率设置为5赫兹，数据以30厘米为间隔进行平均处理。本数据集旨在描述冰封湖泊内的温度、比电导率与密度分布结构，并计算双扩散对流的发生概率。本次采集的数据于2023年11月在4米、10米及15米水深点位获取，并于2024年每月在湖泊维持冰封状态期间，于邻近的15米或24米水深点位开展月度采样。10米水深点位的经纬度为68.62730, -149.60248；4米水深点位为68.63282, -149.59967；15米水深点位为68.62962, -149.61127；约24米水深点位为68.629080, -149.613867。