Juryokine by Adam Bolander

For three months, Gravity Storms have been tearing Yasmik apart and neither the humans nor their winged neighbors, the Sorakines, are safe from them. One hotheaded young Sorakine named Zashiel is convinced that the Storms are being caused deliberately, but she's unable to find evidence to back up her claims. She chooses Toke, a budding inventor studying under the most brilliant mind in Yasmik, to act as her spy- whether he wants to or not. But the task she's set out for him can't be completed by a mere human. Toke must inherit the gravity altering powers of a Sorakine, and become something more than human: a Juryokine.