Modulation of North Pacific Tropical Cyclone Activity by Three Phases of ENSO

Abstract

Tropical Pacific Ocean warming has been separated into two modes based on the spatial distribution of the maximum sea surface temperature (SST) anomaly: an east Pacific warming (EPW) and a central Pacific warming (CPW). When combined with east Pacific cooling (EPC), these three regimes are shown to have different impacts on tropical cyclone (TC) activity over the North Pacific by differential modulation of both local thermodynamic factors and large-scale circulation patterns. In EPW years, the genesis and the track density of TCs tend to be enhanced over the southeastern part and suppressed in the northwestern part of the western Pacific by strong westerly wind shear. The extension of the monsoon trough and the weak wind shear over the central Pacific increases the likelihood of TC activity to the east of the climatological mean TC genesis location. In CPW years, the TC activity is shifted to the west and is extended through the northwestern part of the western Pacific. The westward shifting of CPW-induced heating moves the anomalous westerly wind and monsoon trough through the northwestern part of the western Pacific and provides a more favorable condition for TC landfall. The CPW, on the other hand, produces a large suppression of TC activity in the eastern Pacific basin. In EPC years, all of the variables investigated show almost a mirror image of the EPW.

Explaining Extreme Events of 2014 from a Climate Perspective

“…The variations of TC genesis frequency and intensity in the WNP, from intraseasonal to interdecadal time scales, are related to ISO phases (e.g., Gray 1979;Huang et al 2011;Li and Zhou 2013;, monsoon trough variability (e.g., Ritchie and Holland 1995;Chen et al 2004;Wu et al 2012), the El Niño-Southern Oscillation (e.g., Chan 2005;Du et al 2011;Kim et al 2011), and the PDO (e.g., Yang et al 2012;Liu and Chan 2013). WNP TC genesis frequency depends on the ISO phase ) and might also vary with different climate backgrounds of the EASM (Zhou et al 2009;Wang et al 2012) and PDO phase (Liu and Chan 2013).…”

Interannual variability of tropical cyclone activity along the Pacific coast of North America

“…Collins and Mason (2000) showed that eastern North Pacific tropical cyclone statistics were different in the far eastern North Pacific (east of 116º W) compared with the region west of 116º W. Other analyses also indicate that the seasonal track distribution of tropical cyclones responds to longitudinal variations in ocean temperature anomalies, even if the total seasonal number of storms might not (Irwin and Davis, 1999;Kim et al, 2011).…”

ENSO-based tropical cyclone forecasting using CF-ANFIS

“…Here the author has paid attention to the forecast during El Nino or La Nina episodes while we also have to predict for the neutral phase; therefore, many studies on forecasting cyclones season have further analysed the relationships between climate factors and other circulations not related to ENSO. For example, one of the important factors in predicting seasonal cyclones in Northwest Pacific region is a factor regarding the Western North Pacific Subtropical High often reflected in some layers of the atmosphere on regional circulation in the region [15][16][17][18][19][20][21][22][23][24][25] • N, 115-150 • E. Cyclones cannot occur in the subtropical high-pressure area of Northwest Pacific. Subtropical high pressure in the Pacific northwest region, when intensifying and encroaching the west land, will block the cyclone from sweeping north and west, so in these cases, cyclones tend to land more inclined on the west coast.…”

“…In [17], Kim and colleagues suggest that the warming of the Pacific sea is divided into two distinct modes according the spatial distribution of the sea surface temperature turbulence: warming in the Eastern Pacific (EPW) and warming in the central Pacific (CPW). The 3rd mode is the cooling of the sea surface temperature in the Eastern Pacific region (EPC).…”