  Sources of astrophysical neutrinos can potentially be discovered through the
detection of neutrinos in coincidence with electromagnetic or gravitational
waves. Real-time alerts generated by IceCube play an important role in this
search, acting as triggers for follow-up observations with instruments
sensitive to other wavelengths. Once a high-energy event is detected by the
IceCube real-time program, a complex and time consuming direction
reconstruction method is run in order to calculate an accurate localisation. To
investigate the effect of systematic uncertainties on the uncertainty estimate
of the location, we simulate a set of high-energy events with a wide range of
directions for different ice model realisations, the dominant systematic error
in our localization uncertainty. This makes use of a novel simulation tool,
which allows the treatment of systematic uncertainties with multiple
continuously varied nuisance parameters. These events will be reconstructed
using various reconstruction methods. This study will enable us to include
systematic uncertainties in a robust manner in the real-time direction and
error estimates.
