Correction to “Modeling the ENSO impact of orbitally induced mean state climate changes”

Abstract

[1] In the paper “Modeling the ENSO impact of orbitally induced mean state climate changes” (Journal of Geophysical Research, 117, C05043, doi:10.1029/2011JC007742, 2012) an incorrect version of section 3.1 was published. The correct section 3.1 appears here. [2] To assess the baseline model configuration for the present study, the SSTs from the preindustrial control simulation (0K) are compared with observed SSTs from the Hadley Centre Sea Ice data, HadISST [Rayner et al., 2003] over the period of 1950–1999 (Figures 2a and 2b). The simulated annual mean Equatorial Pacific SSTs (averaged over 120°E–80°W, 5°N–5°S) are about 2°C colder compared to the data (Figures 2a and 2b and Table 2). This is a common bias of non-flux corrected climate models, and possibly due to overly strong trade winds [Guilyardi, 2006] and/or too strong vertical mixing in the ocean. The transient climate response (TCR), the temperature change at the time of CO2 doubling, is 2.9°C in the KCM, which is stronger than in other CMIP3 models (1.2°C–2.6°C) [Park et al., 2009]. [3] The annual cycle in the eastern Tropical Pacific, including the westward propagation of the SST signal, and the semi-annual cycle in the western Tropical Pacific are clearly reproduced by the model (Figures 2c and 2d). However, the amplitude of the annual cycle in the eastern Tropical Pacific is underestimated and it has its peak delayed by 1–2 months. Despite the equatorial cold bias, the zonal SST gradient is comparable to the observations (Table 2) [see also Liu, 1998]. The model overestimates the interannual SST variability in the Western Pacific Warm Pool (WPWP), as indicated by the spatial pattern of the long-term standard deviation. This could be expected given the equatorial cold tongue extends too far to the west. The interannual SST variability is in better agreement with the observations in the eastern Tropical Pacific in terms of both the strength and location of maximum variability (Figures 2e and 2f). [4] The ENSO amplitude in the KCM, defined as the standard deviation of the SST anomalies (SSTA) in the Niño3 region, amounts to 0.91°C, which agrees well with the data (Table 2). However, the small kurtosis and skewness indicate that the Niño3 SSTA distribution is too broad and too symmetric. In particular, the model underestimates the observed tendency toward very strong warm SST anomalies, as indicated by the much larger positive skewness in the Hadley Centre's SST data (Table 2). The spectrum of the Niño3 SST anomalies peaks between 3 and 4 years, which is slightly shorter than that in the observations (Figure 3). In spite of these differences, which in part may result from the different record length (500 years versus 50 years), the preindustrial control simulation represents the important aspects of the mean Tropical Pacific climate and of ENSO reasonably well.