Refers to the time when the morning sky begins to lighten; a somewhat literary or poetic term.
The dawn sky is beautiful.
朝明けとともに鳥が鳴き始めた。
The birds began to sing with the daybreak.
Standard kanji spelling for this noun.
Kana spelling is acceptable, especially in contexts where the kanji might be obscure.
Compound of 朝 (asa, 'morning') and 明け (ake, 'dawning'). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning.