Antarctic Oscillation Index since 1500AD for Dec.-Jan.-Feb.

 

Abstract: Based on multi-proxies from the Southern Hemisphere, an austral summer (Dec-Jan-Feb) Antarctic Oscillation index (DJF-AAO) since 1500 AD was reconstructed with focusing on interannual to interdecadal variability (<50a). By applying multivariate regression method the observational AAO-proxy relations were calibrated and cross-validated for the period of 1957–1989. The regressions were employed to compute the DJF-AAO index in 1500–1956. In verification procedure authors checked the explained variance (r2), reduction of error (RE), and the standard error (SE). The cross-validation was performed by applying a leave-one-out validation method. During the whole reconstruction period, the mean of r2, RE, and SE are 59.9%, 0.47 and 0.67, respectively. These statistics indicate that DJF-AAO reconstruction is relatively skillful and reliable for the last ~460 years. The reconstructed AAO variations on the interannual and interdecadal timescales compare favorably with several shorter SLP-based AAO indices. The leading periods of the DJF-AAO index during the last 500 years are ~2.4, ~2.6, ~6.3, ~24.1, ~37.6-year, which are all significant at the 95% level as estimated by power spectral analysis.

 

Data of the reconstructed Antarctic Oscillation Index since 1500 for Dec.-Jan.-Feb. are available as an Excel file here.

 

For comparison here are other two AAO indices:

1. Marshall’s AAO index: http://www.nerc-bas.ac.uk/icd/gjma/sam.html
2. Fogt’s AAO index: http://polarmet.osu.edu/acd/sam/sam_recon.html

 

References:

1. Zhang Z Y, Gong D Y, He X Z, Lei Y N, Feng S H. Antarctic Oscillation Index Reconstruction Since 1500 AD and Its Variability. Acta Geographica Sinica, 2010, 65(3),259-269. (In Chinese with English Abstract) [张自银, 龚道溢, 何学兆 雷杨娜 冯胜辉. 500年南极涛动指数重建及其变率分析. 地理学报, 2010, 65(3),259-269 [初稿MS-Word 1.4M]

 

2. Zhang ZY, Gong D Y., He X Z, Lei Y N, Feng S H. Statistical reconstruction of Antarctic Oscillation index based on multi-proxies. Atmospheric and Oceanic Science Letters, 2010, 3(5), 283-287. [PDF 1.2M]