Open AccessUncertainties in simulated El Niño–Southern Oscillation arising from internal climate variability
Author(s) -
Sun Chao,
Liu Li,
Li LiJuan,
Wang Bin,
Zhang Cheng,
Liu Qun,
Li RuiZhe
Publication year - 2018
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1002/asl.805
Subject(s) - el niño southern oscillation , climatology , forcing (mathematics) , coupled model intercomparison project , environmental science , amplitude , oscillation (cell signaling) , climate model , ensemble average , southern oscillation , general circulation model , atmospheric sciences , meteorology , climate change , physics , geology , chemistry , oceanography , biochemistry , quantum mechanics
Significant uncertainties exist in El Niño–Southern Oscillation (ENSO) simulations. To investigate the source of these uncertainties, previous studies have primarily focused on the model itself; however, internal climate variability (ICV) as a source of uncertainty has not been sufficiently explored to date. Using the Community Earth System Model–Last Millennium Ensemble (CESM–LME) modeling project and the Coupled Model Intercomparison Project (CMIP), an investigation into uncertainties in simulated ENSO arising from ICV is performed. Results show that external forcing can significantly increase the uncertainties arising from ICV when the simulation length is greater than ~40 years. In addition, the spread in ENSO amplitude arising from ICV accounts for 50% of the total spread within the CMIP5 historical simulations. Finally, the impact of ICV on ENSO varies considerably with simulation length and stabilizes at the threshold of 300–400 years.