Most certainly, it is a noun.
The OED lists two such senses of soar. Note that no lesser poets of the English Language than John Milton in Paradise Lost and Samuel Taylor Coleridge used it.
- The altitude attained in soaring; range of flight upwards. Also fig.
1596 Raigne of Edward III sig. C1 Fly it a pitch aboue the soare
1667 Milton Paradise Lost v. 270 Within soare Of Towring Eagles.
1792 S. Rogers Pleasures Mem. i. 361 That eye so finely wrought
Beyond the search of sense, the soar of thought.
1807 J. Grahame Poems 72 A splendid cloud appeared..; then
hovering, floats, High as the soar of eagle.
1892 Pall Mall Gaz. 26 May 7/1 It requires the highest soar of
fancy to imagine [etc.].
- The act of soaring or rising high.
1817 S. T. Coleridge Satyrane's Lett. ii, in Biogr. Lit. (1882) 252
A liberated bird..who now after his first soar of freedom poises
himself in the upper air.
1820 Scott Abbot I. xv. 315 It is ill whistling for a hawk when
she is once on the soar.
1870 D. G. Rossetti House of Life in Poems iv Just when at that
swallow's soar Your neck turned so.
in extended use. 1825 T. L. Beddoes Let. to B. W. Procter in Poems
(1851) I. 166 Wings upraise thee long In the unvacillating soar of
1864 J. R. Lowell Fireside Trav. 306 There is none of the spring
and soar which one may see even in the Lombard churches.
1887 G. Saintsbury Hist. Elizabethan Lit. iv. 102 A little later
we meet with that towering soar of verse which is also peculiar to the