Future change of the Indian Ocean basin-wide and dipole modes in the CMIP5

Abstract

The Indian Ocean sea surface temperature (SST) variability has been represented with the two dominant variability modes: the Indian Ocean basin-wide (IOBW) and dipole (IOD) modes. Here we investigate future changes of the two modes together with mean state and El Niño and Southern Oscillation (ENSO) relationship under the anthropogenic global warming using 20 coupled models that participated in the phase five of Coupled Model Intercomparison Project by comparing the historical run from 1950 to 2005 and the RCP 4.5 run from 2050 to 2099. The five best models are selected based on the evaluation of the 20 models' performances in simulating the two modes and Indian Ocean basic state for the latest 56 years. They are capable of capturing the IOBW and IOD modes in their spatial distribution, seasonal cycle, major periodicity, and relationship with ENSO to some extent. The five best models project the significant changes in the Indian Ocean mean state and variability including the two dominant modes in the latter part of twenty-first century under the anthropogenic warming scenario. First, the annual mean climatological SST displays an IOD-like pattern change over the Indian Ocean with enhanced warming in the northwestern Indian Ocean and relatively weaker warming off the Sumatra-Java coast. It is also noted that the monthly SST variance is increased over the eastern and southwestern Indian Ocean. Second, the IOBW variability on a quasibiennial time scale will be enhanced due to the strengthening of the ENSO-IOBW mode relationship although the total variance of the IOBW mode will be significantly reduced particularly during late summer and fall. The enhanced air-sea coupling over the Indian-western Pacific climate in response to El Nino activity in the future projection makes favorable condition for a positive IOD while it tends to derive relatively cold temperature over the eastern Indian Ocean. This positive IOD-like ENSO response weakens the relationship between the eastern Indian Ocean and El Nino while strengthens the relationship with western Indian Ocean. Third, the IOD mode, intrinsic coupled mode of the Indian Ocean may not be changed appreciably under the anthropogenic global warming.

Indo-western Pacific ocean capacitor and coherent climate anomalies in post-ENSO summer: A review

“…An early study based on a single model (Zheng et al, 2011) showed that in a warmer climate both the IO warming and AAC persist longer in post-El Niño summer, indicating a strengthening of the positive feedback from the interaction of these interannual ocean-atmosphere anomalies. A similar strengthening of the IPOC mode takes place in a subset of CMIP5 models that are deemed to simulate the mode well in current climate (Chu et al, 2014). showed that by changing the moist adiabatic lapse rate, climate warming amplifies the tropospheric Kelvin wave that connects the Indo-western Pacific oceans in post-El Niño summer.…”

Interbasin coupling between the tropical Indian and Pacific Ocean on interannual timescale: observation and CMIP5 reproduction

“…A total of 20 coupled general circulation models (CGCMs) that participated in the CMIP5 were utilized in this study, following several previous studies (Chu et al 2014;Lee et al 2014;Chen et al 2016). Although more CMIP5 models could be available now, the use of the same 20 models provides a fair comparison with the previous results in the multimodel framework.…”

“…Taking into account the limited sample size in observational data, the Coupled Model Intercomparison Project phase 5 (CMIP5) historical simulations for the twentieth century are used. It has been reported that most CMIP5 models reasonably capture spatial distribution, seasonality, and periodicity of the IOBM and IOD modes (Du et al 2013;Chu et al 2014;Liu et al 2014) in addition to ENSO (Bellenger et al 2014;Lee et al 2014;Chen et al 2016). Furthermore, several studies (e.g.…”

“…Furthermore, several studies (e.g. Ohba et al 2010;Kug and Ham 2012;Chu et al 2014) showed the CMIP models' fidelity in reproducing the interannual IO-ENSO coupling. However, it is still unclear how well the models simulate the interbasin coupling.…”

Future Change Using the CMIP5 MME and Best Models: I. Near and Long Term Future Change of Temperature and Precipitation over East Asia

“…이 모델들은 해양, 대기 그리고 지구상 생물권에 존재하는 탄소의 양 사이에서 탄소의 중요한 플럭스 를 설명하고, 어떤 경우에는 상호적인 전조가 되는 에 어로졸과 화학적, 역학적인 식생 요소를 포함하는 생 물-지구화학 요소를 포함한다 (Taylor et al, 2012;Lee and Wang, 2014;Chu et al, 2014). 그러므로 CMIP5 문혜진·김병희·오효은·이준이·하경자 405 는 CMIP3 보다 자연적인 강제력과 에어로졸에 더 크 게 반응할 것이다 (Yeh et al, 2012).…”