Adjective modifier

• regular: The regular diurnal, seasonal and solar cycle variations were then removed from the data by substracting from these the quiet standard value.

Modifies a noun

• raptor: The last group in the diurnal raptors is the true falcons.

• aberration: The transformation from apparent to topocentric consists of allowing for diurnal aberration.

• variation: These diurnal variations cease to be sensible at a depth of 2 or 3 meters.

• rhythm: The difference between these measures cannot be explained by an altered timing of the diurnal rhythm.

• variability: It could be the diurnal variability of solar input, or the annual or seasonal variation of heating.

• tide: The wave like structure is caused by the diurnal tide.

Modifying Another Word

• mainly: Mainly diurnal, with a maximum lifespan of 18 months.

• predominantly: They are predominantly diurnal ( daytime ) and feed on a variety of heathland plants.