Track-dependency of tropical cyclone risk in South Korea

Abstract

Abstract. In tropical cyclone (TC) risk assessment, many of previous studies have attempted to construct the statistical relationship of TC damage and three risk elements-exposure, vulnerability, and hazard. For hazard parameters, central minimum pressure, maximum wind speed, and size have been widely utilized while the track was not mainly considered as one of critical hazard parameters. This study shows that, in a decision tree analysis for TCs that made landfall in South Korea during 1979-2010, track is the primary factor to predict damage occurrence. Small track deviations £ 250 km could 10 distinctively change the damage maps for South Korea. This significant track-dependency of TC risk exists because TC track is responsible for the realization of the other hazards developing from a potential to an active hazard, such as wind gusts or downpours at a given settlement. TC track determines the overall severity and spatial distribution of the active hazards by changing the combination of multiple factors: physical geography experience, duration of influence, and relative position of dangerous semicircle side of the TC. These results indicate that large uncertainty in future track projection may seriously 15 mislead future TC risk modeling because trivial track projection error alone can produce severe errors in damage projection even when TC frequency and intensity value is precise and accurate.

Asymmetric Wave Distributions of Tropical Cyclones Based on CFOSAT Observations

“…In the SH, there are seven TCs in the SP and 10 in the SIO. The wind is clockwise rotational, and the TC translation speed and rotational wind field are additive on the left side of the TC track (Nam et al, 2017 To our knowledge, there are no studies to demonstrate the TC wave distributions in the SH to date. We hypothesize that the distribution of TC waves is asymmetric, with the peak on the left, in contrast to the NH.…”

“…For the wind and wave interaction under the TC conditions, subjecting to steady wind forcing, the wave development follows the same wind-wave growth functions (Hwang, 2016;Hwang & Walsh, 2016;Young, 1988Young, , 2003. Under TC wind forcing, ocean waves often grow high and dangerous, and the highest waves occupy the right side of the dangerous semicircle of TCs in the Northern Hemisphere (Arakawa, 1954;Nam et al, 2017). The spatial distribution of ocean wave heights has asymmetric structure under TC condition (e.g., P. C. Chu & Cheng, 2008;H.…”