Characteristics of tropical cyclones in the southwest pacific

Abstract

Geographic and meteorological characteristics of 479 tropical cyclones (TCs) in a study domain in the Southwest Pacific (defined by 135°E – 120°W and 5 – 65°S) over the past 48 TC seasons, from 1969 – 1970 to 2016 – 2017, were examined using the latest Southwest Pacific Enhanced Archive of TCs dataset. Examined metrics include the TCs’ geographic distributions, numbers, intensities, length in days (TC days), accumulated cyclone energy (ACE), and power dissipation index (PDI). The results show increasing TC activities in the western, northwestern, northern, and central subdomains of the nine subdomains in the study domain. The average latitudes of TC genesis and maximum intensity remained almost unchanged. Most TCs took southward to southeastward paths, and most attained their maximum intensities in the western and central parts of the study domain. The annual number of TCs and TC days decreased over the study period, while the numbers of stronger TCs slightly increased, and stronger TC days increased. The highest annual lifetime-maximum intensity and average annual lifetime-maximum intensity also increased. The highest annual maximum intensification rates did not change much over the study period, nor did ACE and PDI. The results show correlations between the highest annual lifetime-maximum intensity and average sea surface temperature (SST) variations, as well as correlations between TC days and average SST variations in the region.