Diurnaalinen

Diurnaalinen is a Finnish adjective meaning related to the daytime or diurnal. The term is used in everyday language and in scientific contexts to denote patterns tied to the 24-hour day cycle. It derives from the Latin diurnus, meaning daily.

In biology, diurnal organisms are active during daylight hours. Examples include many birds, bees, and humans. The term contrasts with nocturnal (active at night) and crepuscular (most active at dawn and dusk). In meteorology, diurnal variation describes daily fluctuations in weather-related factors such as temperature, humidity, and wind.

Diurnal rhythms are generated by internal circadian clocks and are synchronized by environmental cues, primarily light. Diurnal variation is observable in physiological processes such as body temperature, hormone secretion, alertness, and metabolism, which typically rise during the day and fall at night.

In Finnish scientific writing, diurnaalinen appears in phrases like diurnaalinen rytmi (diurnal rhythm) or diurnaaliset vaihtelut (diurnal fluctuations), indicating daytime-related timing across disciplines such as biology, ecology, and meteorology.

See also: diurnal, nocturnal, crepuscular.