A0 The first Air Mode normally 270 .. 290 Hz
The surface of the violin body is too small to efficiently radiate low frequencies. A0 relies on the vibration of the air inside the violin, which pumps air through the f-holes and also moves the plates, allowing additional low frequency radiation. Having an antinode near the f-holes, AO can radiate strongly with only a very small amount of plate movement. This lowest strong air mode is crucial to the fullness of a violin on the low end.
The next air mode A1 does not have an antinode near the f- holes so cannot radiate effectively in this way though it can lead to radiationThe air sloshes from one end of the cavity to the other, as seen in Bissingers AIR ANIMATIONS
All these mode shapes and more can be seen in the Polytec 3D laser scans, and in the Modal Video by Eugene Schenkman.
For in depth study, please see the articles by George Bissinger