A Global Hybrid Tropical Cyclone Risk Model based upon Statistical and
Coupled Climate Models
Abstract
Tropical cyclones (TCs) are among the most destructive natural hazards
and yet, quantifying their financial impacts remains a significant
methodological challenge. It is therefore of high societal value to
synthetically simulate TC tracks and winds to assess potential impacts
along with their probability distributions for e.g., land use planning
and financial risk management. A common approach to generate TC tracks
is to apply storm detection methodologies to climate model output, but
such an approach is sensitive to the method and parameterization used
and tends to underestimate intense TCs. We present a global TC model
that melds statistical modeling, to capture historical risk features,
with a climate model large ensemble, to generate large samples of
physically-coherent TC seasons. Integrating statistical and physical
methods, the model is probabilistic and consistent with the physics of
how TCs develop. The model includes frequency and location of
cyclogenesis, full trajectories with maximum sustained winds and the
entire wind structure along each track for the six typical cyclogenesis
basins from IBTrACS. Being an important driver of TCs globally, we also
integrate ENSO effects in key components of the model. The global TC
model thus belongs to a recent strand of literature that combines
probabilistic and physical approaches to TC track generation. As an
application of the model, we show global risk maps for direct and
indirect hits expressed in terms of return periods. The global TC model
can be of interest to climate and environmental scientists, economists
and financial risk managers.