It is inertial adjustment to pressure forcing that inhibits the growth of TC divergence at the outflow level, and so defines the “outflow resistance”. The relative strength of inertial adjustment is defined as the inertial frequency, compared to other adjustment frequencies such as the Brunt Vaisalla frequency or the divergence tendency itself. We have derived and tested a formulation for the absolute inertial frequency for the outflow environment, which precisely defines the relative strength of inertial adjustment to pressure forcing and the resistance it causes.
We have have applied this formulation to hurricane outflow, as diagnosed with assimilated TCI observations to demonstrate its effectiveness in determining outflow resistance and intensification potential. Results will be forthcoming at the oral presentation.