Answer:
Searing 'cross the pitchยญ-black skies, I scream in celebration, Yet moments later, my outburst through, I am naught but imagination.
Something wholly unreal, yet seems real to I. Think my friend, tell me where does it lie?
What goes up but never comes down?
What can be measured but not seen?
It's like food but water kills it. What is it?
If itโs information you seek, come and see me. If itโs pairs of letters you need, I have consecutively three. What am I?