Dimictic lake
(重定向自Dimictic)

Dimictic lakes mix from the surface to bottom twice each year. Dimictic lakes are holomictic, a category which includes all lakes which mix one or more times per year. During winter, they are covered by ice. During summer, they are thermally stratified, with temperature-derived density differences separating the warm surface waters (the epilimnion), from the colder bottom waters (the hypolimnion).