From the publisher's website:
Air — perhaps the most mysterious of the primal elements of creation, an invisible medium through which we walk and in whose arms a rare few can fly. The power of air and wind, on their own, seem magical even in our modern world—how much more so in the medieval past? Where does the wind come from, what is it made of, and how can it wield so much power?
The pages of fantasy fiction are filled with the mysteries of air-castles in the sky, weapons made of wind, and creatures like djinni and elementals, who seem to be the very air itself brought to life. Certainly, the Pathfinder Roleplaying Game Core Rulebook captures some of the power and mystery contained in the element of air — but that is expressed mostly in the form of movement-based or defensive spells when, as anyone who has ever been caught unprotected in the face of an oncoming gale will attest, air can also serve as a most formidable weapon.
Air vs. Storm
Air magic often overlaps with storm and weather magic, with spells such as control weather and control winds both being able to create tornadoes and hurricane-force winds under the right conditions. For the most part, The Genius Guide to Air Magic focuses only on air spells, leaving more lightning- and rain-focused spells for other venues. Even so there is some overlap (thunder, being a phenomenon entirely of air, sneaks into a few of our spells), and the new class options presented at the end of this product go further afield than the spells themselves (the druidic storm lord being the most obvious case). We also explore some concepts connected to specifically named winds (such as the chinook and sirocco spells), some of which have very little bearing on a scientific understanding of how air actually behaves and functions. We beg the reader’s indulgence if we wander further than expected from a focus on pure aerothurgy.