Process-based analysis of climate model ENSO simulations : intermodel consistency and compensating errors
MetadataShow full item record
Systematic and compensating errors can lead to degraded predictive skill in climate models. Such errors may be identified by comparing different models in an analysis of individual physical processes. We examine model simulations of El Niño–Southern Oscillation (ENSO) in five Coupled Model Intercomparison Project (CMIP) models, using transfer functions to analyze nine processes critical to ENSO's dynamics. The input and output of these processes are identified and analyzed, some of which are motivated by the recharge oscillator theory. Several errors and compensating errors are identified. The east-west slope of the equatorial thermocline is found to respond to the central equatorial Pacific zonal wind stress as a damped driven harmonic oscillator in all models. This result is shown to be inconsistent with two different formulations of the recharge oscillator. East Pacific sea surface temperature (SST) responds consistently to changes in the thermocline depth in the eastern Pacific in the five CMIP models examined here. However, at time scales greater than 2 years, this consistent model response disagrees with observations, showing that the SST leads thermocline depth at long time scales. Compensating errors are present in the response of meridional transport of water away from the equator to SST: two different models show different response of the transport to off-equatorial wind curl and wind curl response to East Pacific SST. However, these two models show the same response of meridional transport to East Pacific SST. Identification of errors in specific physical processes can hopefully lead to model improvement by focusing model development efforts on these processes.
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Atmospheres 119 (2014): 7396–7409, doi:10.1002/2013JD021415.
Showing items related by title, author, creator and subject.
Levang, Samuel J.; Schmitt, Raymond W. (American Meteorological Society, 2015-08-15)The global water cycle is predicted to intensify under various greenhouse gas emissions scenarios. Here the nature and strength of the expected changes for the ocean in the coming century are assessed by examining the ...
Deshayes, Julie; Curry, Ruth G.; Msadek, Rym (American Meteorological Society, 2014-05-01)The subpolar North Atlantic is a center of variability of ocean properties, wind stress curl, and air–sea exchanges. Observations and hindcast simulations suggest that from the early 1970s to the mid-1990s the subpolar ...
Marine ecosystem dynamics and biogeochemical cycling in the Community Earth System Model [CESM1(BGC)] : comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 scenarios Moore, J. Keith; Lindsay, Keith; Doney, Scott C.; Long, Matthew C.; Misumi, Kazuhiro (American Meteorological Society, 2013-12-01)The authors compare Community Earth System Model results to marine observations for the 1990s and examine climate change impacts on biogeochemistry at the end of the twenty-first century under two future scenarios ...