The phrase "air of determination" is correct and usable in written English.
It can be used to describe a person's demeanor or attitude that conveys a strong sense of resolve or purpose.
Example: "As she walked into the room, she carried an air of determination that inspired everyone around her."
Alternatives: "a sense of resolve" or "an aura of determination."
He has a fresh air of determination, self-assurance, even gaiety.
Rose's first number, "Some People," a hymn of ambition sung to her father (William Parry), garnishes the usual air of determination with an instinctive little-girl flirtiness.
A regime of hyperbaric chambers and ice baths and a diet of ostrich steaks and wheatgrass juice were a long way in the future but even then she had an air of determination beneath the modesty and charm.
Charles Kinnoull, the charity's chairman, told the Guardian the meeting had an air of "optimistic determination".
When she pushes her astringent voice to its limits at the ends of big ballads, her singing takes on an air of straining determination.
Adults approach with an air of wary determination, intently regarding the screen and carefully pressing it after reading all possible options several times.
And then, all of a sudden, she was no longer the small, apologetic woman, vague and cheerfully flustered; she had gleaming eyes, a stubborn mouth and an air of utter determination and concentration.
11.42am: Protesters beginning to congregate in central London now, ahead of the 12 noon set off for the march, writes Matthew Taylor, of whom I can only find this rather large picture: Thousands of students are starting to gather outside the LSE now [some of them enjoying pre Demo pint] and there is an air of excited determination as they wait for the march to start.
As I walked with Muscovites I was impressed by the air of quiet determination and resolve.
The two concerts of short pieces by six composition fellows had an air of excitement and determination in the performance.
Where stroke patients used to be wheeled down gloomy linoleum corridors into dark Victorian wards equipped with little more than rows of adjustable exercise beds, now there's an air of hope and determination From the pine floors, and coffee dispensers, to the cheerful decor, television, and shelves overflowing with paperbacks, magazines, and picture books, the atmosphere is upbeat and positive.
