May 18, 2015

Association of Taiwan’s Rainfall Patterns with Large-Scale Oceanic and Atmospheric Phenomena

Yi-Chun Kuo, Ming-An Lee, and Mong-Ming Lu
Advances in Meteorology
  • Presents a 50-year (1960–2009) monthly rainfall gridded dataset produced by the Taiwan Climate Change Projection and Information Platform Project
  • The gridded data (5 × 5 km) displayed influence of topography on spatial variability of rainfall
  • The results of the empirical orthogonal functions (EOFs) analysis revealed the patterns associated with the large-scale sea surface temperature variability over Pacific
  • The first mode (65%) revealed the annual peaks of large rainfall in the southwestern mountainous area, which is associated with southwest monsoons and typhoons during summertime
  • The second temporal EOF mode (16%) revealed the rainfall variance associated with the monsoon and its interaction with the slopes of the mountain range
  • States that this pattern is the major contributor to spatial variance of rainfall in Taiwan, as indicated by the first mode (40%) of spatial variance EOF analysis
  • The second temporal EOF mode correlated with the El Niño Southern Oscillation (ENSO)
  • Finds in particular, that during the autumn of the La Niña years following the strong El Niño years, the time-varying amplitude was substantially greater than that of normal years
  • The third temporal EOF mode (7%) revealed a north-south out-of-phase rainfall pattern, the slowly evolving variations of which were in phase with the Pacific Decadal Oscillation
  • States that because of Taiwan’s geographic location and the effect of local terrestrial structures, climate variability related to ENSO differed markedly from other regions in East Asia