Tree-ring width wavelet and spectral analysis of solar variability and climatic effects on a Chilean cypress during the last two and a half millennia

Abstract

Abstract. Spectral and wavelet analysis were performed on a tree ring width time series obtained from a 2500 yr old cypress tree (Fitzroya cupressoides) from Costa del Osorno, Chile. The periods for analysis were selected at 95% confidence level. Both periodicities characteristic of solar activity and climatic variations were found in this tree ring width series. The 11 and 22 years solar cycle periods were present in tree ring data with a confidence level above 98%. This indicates the solar modulation of climatic variations is being recorded by the tree ring grown. However wavelet analysis shows that these are present only sparsely. Short-term variations, between 2-5 years, are also present in tree ring data, and are shown by wavelet maps to be a more permanent characteristic. This time scale is a signature of ENSO events. Long-term variations, above 200 years, are also present in tree ring data. The spectral analysis performed in this work shows that this species has the ability to record solar-ENSO variations that seems to be affecting the local environment of tree growth, and also that this region was influenced by ENSO events at least in the past 2500 yr interval covered by this study.

Wavelet analysis of the singular spectral reconstructed time series to study the imprints of solar–ENSO–geomagnetic activity on Indian climate

“…The SSN-SOI spectra (Fig. 5c) show a strong correlation at an 11-year solar cycle, which is stronger during 1910-1950and 1960(Rigozo et al, 2002, suggesting the strongest El Niño and La Niña events, indicating solar modulation on ENSO (Kodera and Kuroda, 2005;Kryjov and Park, 2007). These results show a good correspondence in response to growth of the tree-ring time series during the intense solar activity.…”

“…Several recent studies of solar-geomagnetic effects on climate have been examined on both global as well as on regional scales (Lean and Rind, 2008;Benestaed and Schmidt, 2009;Meehl et al, 2009;Kiladis and Diaz, 1989;Pant and Rupa Kumar, 1997;Gray et al, 1992;Wiles et al, 1998;Friis and Svensmark, 1997;Rigozo et al, 2005;Feng et al, 2003;Tiwari and Srilakshmi, 2009;Chowdary et al, 2006Chowdary et al, , 2014Appenzeller et al, 1998;Proctor et al, 2002;Tsonis et al, 2005;De Freitas and Mclean, 2013). The Sun's long-term magnetic variability caused by the sunspots is considered to be one of the primary drivers of climatic changes.…”

Paleoclima de La Guajira, Colombia; según los anillos de crecimiento de Capparis odoratissima (Capparidaceae)

“…No obstante, no podría descartarse que corresponda con un segundo armónico de la señal de seis años encontrada por Ramírez (2007) en Parkinsonia praecox en la misma región, así como a señales de ciclo muy próximo encontradas por Schöngart et al (2004) en la Amazonia, por López et al (2006) en Casma, Perú, por Fichtler et al (2004) en Namibia y por Stahle et al (1998) en Indonesia. Pero también podría deberse al ciclo corto de 11 años de las manchas solares, tal como han sido encontradas en los anillos de Fitzroya cupressoides en Chile (Rigozo et al 2005).…”

Periodicities in mean sea-level fluctuations and climate change proxies: Lessons from the modelling for coastal management

“…It discards very little data and weights the data relatively evenly (Park et al, 1987). The MTM detects small amplitude oscillations in a time series and uses an internal statistical F-test to determine the significance of the periodicity (Rigozo et al, 2005). As the number of tapers increases, there are more estimates of the power spectrum and the variance in the estimate decreases, but as the bandwidth for each taper increases, there are wider peaks increasing the bias in the estimate.…”