Тип публикации: доклад, тезисы доклада, статья из сборника материалов конференций
Конференция: International Multidisciplinary Scientific Geoconference (SGEM); Albena, BULGARIA; Albena, BULGARIA
Год издания: 2015
Ключевые слова: tree-ring chronologies, time series, spectral decomposition, white noise, climate reconstruction, MTM-approach, singular spectral analysis, cluster analysis, low frequency
Аннотация: Tree-ring chronologies (dendrochronological time series) are an important proxy source for oblique high-resolution information about climate and environmental changes in the past and present. Often the time series signals are associated with direct external periodic forcing (e.g., annual irradiance, seasonal moisture regimes, etc.)Показать полностью, or with the internal oscillations within biological systems themselves (e.g., age-dependent trends, components of competition, etc). In most cases, the observed signal is interpreted as superposition of different internal and external influences. In most cases due to unstable frequency, amplitude and phase of analyzed signals the significance of power spectrum peaks may be tested by the "red-noise" null hypothesis, with a number of additional assumptions concerning possible causes for the observed instability. The goal of this paper is to verify information losses in the case of testing a power spectrum by the "white-noise" null hypothesis in order to detect significant cycles in dendrochronological time series. The new approach described herein allows us to (1) obtain an adequate spectral decomposition of different tree-ring chronologies; (2) analyze spatial comparisons of different time series, specifying possible causes for disagreement; and (3) build new long-term reconstructions of different climatic series by different cyclical components. Moreover, the approach helps to extend super long-term tree-ring chronologies by low-frequency components, to verify temporal periods in the past for which there are no good statistical estimations, which will enable extension of existing climatic reconstructions.
Журнал: WATER RESOURCES, FOREST, MARINE AND OCEAN ECOSYSTEMS, SGEM 2015, VOL II
Номера страниц: 537-544
ISSN журнала: 13142704
Место издания: SOFIA
Издатель: STEF92 TECHNOLOGY LTD