Uncertainty of Tropical Cyclone Wind Radii on Sea Surface Temperature Cooling

Abstract

TCs with winds greater than 64 kt (1 kt = 0.514 ms −1 ) and occur in the western North Pacific, can be especially devastating when making landfall. With increasing Asian and western Pacific population and economic prosperity, coastal areas are becoming more vulnerable to typhoons (e.g., Emanuel, 2020;Potter et al., 2019;Pun et al., 2019), and changes in climate such as sea level rise will only increase that vulnerability. The most effective way to mitigate TC damage and save expensive assets, is to increase TC prediction skill so that appropriate pre-storm preparations are completed in a timely manner. Unfortunately, increasing skill has proven to be difficult. Enormous efforts in the past few decades have led to improvements in TC track prediction, but intensity prediction skill is still limited, especially in the cases of rapid intensification (RI;

Seasonal differences in tropical cyclone—induced sea surface cooling in the western North Pacific

“…The difference in TC size between the two seasons is statistically significant at the 90% confidence level ( p = 0.07). Previous studies show that TC‐induced SST cooling increases with the size of the TC (Pun et al, 2021). However, our analysis shows that despite the slightly bigger size of TCs in autumn, the TC‐induced SST cooling in this season is less than in summer.…”

“…The other TC characteristics that significantly impact TC‐induced SST cooling are the translation speed and size of the TC (Pun et al, 2018; Pun et al, 2021). Fast‐moving and smaller TCs cause less SST cooling than slow‐moving and larger TCs (Mei & Pasquero, 2013).…”

“…Further analysis of the differences in the ocean subsurface conditions along TC tracks in the two seasons is given in Section 3.3. The other TC characteristics that significantly impact TC-induced SST cooling are the translation speed and size of the TC (Pun et al, 2018;Pun et al, 2021). Fast-moving and smaller TCs cause less SST cooling than slow-moving and larger TCs (Mei & Pasquero, 2013).…”

Numerical Study of the Response of Typhoon Hato (2017) to Grouped Mesoscale Eddies in the Northern South China Sea

“…The 3DPWP resolved momentum flux through the bulk transfer formula and the transfer coefficient for the surface enthalpy flux is 1.3 × 10 3 . By containing the primary processes controlling SST cooling during a TC passage, such as vertical mixing, upwelling, horizontal advection, and air‐sea heat exchange, the 3DPWP model has been widely used and proven to be successful in the investigation of the oceanic response to TCs (Balaguru et al., 2015; Guan et al., 2014; Lin et al., 2021; Pun et al., 2018; Pun et al., 2021). The initial and boundary conditions for the atmosphere model were constructed with the National Centers for Environmental Prediction (NCEP) FNL (Final) Operational Model Global Tropospheric Analyses (https://rda.ucar.edu/datasets/ds083.2/), which has a 6‐hourly temporal resolution and 1° × 1° spatial resolution.…”