The ecology of a lake is mainly controlled by mixing processes; particularly, in tropical oligomictic lakes, the occurrence frequency and magnitude of convection govern the vertical mixing of chemicals and organisms. In this study, vertical profiles of water temperature, dissolved oxygen, electric conductivity, turbidity, and chlorophyll a were measured in 2014, 2015, 2017, and 2018 in two Sumatran deep lakes, Lakes Maninjau and Singkarak. In Lake Maninjau, intensive surveys on the profiles were also conducted in three different seasons in 2018. The comparison of the profiles between 2015 and 2017 indicated the events of large convection down to the lake bottoms happened in both of the lakes. Similarly, small convection down to around 30 m depth was found in the period between May and Jul, 2018. Air temperature drops up to five degrees centigrade were observed in these periods, confirmed by the changes in lake surface temperature estimated by MODIS imagery for the lakes. The magnitudes of the convective events were discussed with the observed amounts of heat loss and the estimated heat transfer through lake surface. Furthermore, the influences of such events on anoxic hypolimnetic waters were evaluated and considered from the view of climate change.

湖泊的生态主要受混合过程控制；特别是在热带低聚湖泊中，对流的发生频率和强度控制着化学物质和生物体的垂直混合。在这项研究中，2014、2015、2017 和 2018 年在两个苏门答腊深湖 Maninjau 和 Singkarak 中测量了水温、溶解氧、电导率、浊度和叶绿素 a 的垂直剖面。2018年，马宁焦湖还对三个不同季节的剖面进行了密集调查。2015年和2017年剖面的对比表明，两个湖泊都发生了下沉到湖底的大对流事件。同样，在 2018 年 5 月至 7 月期间发现了深度约 30 m 的小对流。在这些时期观察到气温下降高达 5 摄氏度，这由 MODIS 湖泊图像估计的湖面温度变化证实。对流事件的大小与观察到的热损失量和通过湖面的估计传热进行了讨论。此外，从气候变化的角度评估和考虑了此类事件对缺氧下沉水的影响。