A fourteen-year time series of rainwater 7Be and 210Pb fluxes in northern Taiwan

Rainwater samples were collected in northern Taiwan at weekly intervals continuously for 14 years (1996-2010). The samples were analyzed for 7Be and 210Pb by gamma spectrometry to obtain fluxes of these two nuclides. Spectral analysis of the time series reveals oscillations at annual, interannual and decadal periodicities. The annual and interannual oscillations are closely related to precipitation through East Asian monsoon and ENSO, respectively. The decadal variability may be a consequence of low-frequency ENSO oscillations and eleven-year solar cycle forcing. Such a long record is instrumental to study factors controlling the changes of regional meteorology and climate on monthly to decadal time scales.