A31E-0112
Decadal Variation’s Offset of Global Warming in Recent Tropical Pacific Climate
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Sae-Rim Yeo, APEC Climate Center, Busan, South Korea, Sang-Wook Yeh, Hanyang University, Marine Sciences and Convergent Technology, Seoul, South Korea, Kwang-Yul Kim, Seoul National University, Seoul, South Korea and WonMoo Kim, Ewha Womans University, Seoul, South Korea
Abstract:
Despite the increasing greenhouse gas concentration, there is no significant warming in the sea surface temperature (SST) over the tropical eastern Pacific since about 2000. This counterintuitive observation has generated substantial interest in the role of low-frequency variation over the Pacific Ocean such as Pacific Decadal Oscillation (PDO) or Interdecadal Pacific Oscillation (IPO). Therefore, it is necessary to appropriately separate low-frequency variability and global warming from SST records. Here we present three primary modes of global SST as a secular warming trend, a low-frequency variability, and a biennial oscillation through the use of novel statistical method. By analyzing temporal behavior of the three-mode, it is found that the opposite contributions of secular warming trend and cold phase of low-frequency variability since 1999 account for the warming hiatus in the tropical eastern Pacific. This result implies that the low-frequency variability modulates the manifestation of global warming signal in the tropical Pacific SST. Furthermore, if the low-frequency variability turns to a positive phase, warming in the tropical eastern Pacific will be amplified and also strong El Niño events will occur more frequently in the near future.
