A studying of solar-ENSO correlation with southern Brazil tree-ring index (1955–1994)
N. R. Rigozo1,2,3, D. J. R. Nordemann3, M. Pereira de Souza Echer1, E. Echer3, and A. Prestes31Faculdade de Tecnologia Thereza Porto Marques – FAETEC, CEP 12308-320, Jacareí, Brazil 2LARAMG – Laboratório de Radioecologia e Mudanças Globais/Departamento de Biofísica e Biometria da Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro - RJ, Brazil 3Instituto Nacional de Pesquisas Espaciais – INPE, CP 515, 12201-970 São José dos Campos, Brazil
Received: 24 Aug 2005 – Discussion started: 07 Nov 2005
Abstract. Solar activity, volcanic aerosol, El Niño-Southern Oscillation and global temperature anomalies effects on Southern Brazil tree growth rings are presented through multiple linear analysis. Linear correlations were made on annual, 10 year running averages and band pass filter. For annual averages, the correlation coefficients were low, and the 10 years running average correlations the coefficient correlations were much higher. The multiple regression of 2 to 5 year band pass filter indicates that 60% of the variance in tree ring index was explained by volcanic eruptions, Southern Oscillation Index and temperature anomalies. The multiple regression of 10 year running averages indicates that 84% of the variance in tree ring index was explained by solar activity and another time series. These results indicate that the effects of solar activity, volcanic eruptions, ENSO and temperature anomalies on tree rings are better seen on long timescales than volcanic eruption, ENSO and temperature anomaly.
Rigozo, N. R., Nordemann, D. J. R., Pereira de Souza Echer, M., Echer, E., and Prestes, A.: A studying of solar-ENSO correlation with southern Brazil tree-ring index (1955–1994), Clim. Past Discuss., 1, 215-230, doi:10.5194/cpd-1-215-2005, 2005.