  In this work, using solutions from a local gyrokinetic flux-tube code
combined with higher order ballooning theory, a new analytical approach is
developed to reconstruct the global linear mode structure with associated
global mode frequency. In addition to the isolated mode (IM), which usually
peaks on the outboard mid-plane, the higher order ballooning theory has also
captured other types of less unstable global modes: (a) the weakly asymmetric
ballooning theory (WABT) predicts a mixed mode (MM) that undergoes a small
poloidal shift away from the outboard mid-plane, (b) a relatively more stable
general mode (GM) balloons on the top (or bottom) of the tokamak plasma. In
this paper, an analytic approach is developed to combine these disconnected
analytical limits into a single generalised ballooning theory (GBT). This is
used to investigate how an IM behaves under the effect of sheared toroidal
flow. For small values of flow an IM initially converts into a MM where the
results of WABT are recaptured, and eventually, as the flow increases, the mode
asymptotically becomes a GM on the top (or bottom) of the plasma. This may be
an ingredient in models for understanding why in some experimental scenarios,
instead of large edge localised modes (ELMs), small ELMs are observed. Finally,
our theory can have other important consequences, especially for calculations
involving Reynolds stress driven intrinsic rotation through the radial
asymmetry in the global mode structures. Understanding the intrinsic rotation
is significant because external torque in a plasma the size of ITER is expected
to be relatively low.
