This research examines the EI Niño-Southern Oscillation (ENSO) phenomenon in the NCAR Climate System Model (CSM). The focus is on changes in ENSO amplitude and frequency on interdecadal (10 to 100 year) time scales, compared with the changes observed in the real system. Using a 300-year simulatio... Show moreThis research examines the EI Niño-Southern Oscillation (ENSO) phenomenon in the NCAR Climate System Model (CSM). The focus is on changes in ENSO amplitude and frequency on interdecadal (10 to 100 year) time scales, compared with the changes observed in the real system. Using a 300-year simulation from the CSM, global fields of sea surface temperature (SST) are used to characterize El Niño structure, amplitude, and frequency. Time series derived from these fields are analyzed using various statistical techniques including wavelet analysis. The observations show that the CSM reasonably simulates ENSO events with regard to structure. The CSM's ENSO amplitude is smaller than that seen in reality, and the ENSO activity is located too far west in the Pacific. Both the observations and the CSM data demonstrate interdecadal changes in ENSO. The results are discussed in relation to the recent upward trend in ENSO amplitude and frequency that has been observed and possible links with global warming. Show less
