English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The trajectory of Earth about the Sun is perturbed by torques exerted by theMoon and Sun, and also the four giant planets. These provoke variations ofinsolation at Earth surface, known as kyr-long Milankovi\'c cycles. The concepthas been extended to the shorter time scales of years to centuries, that arerelevant to tree growth. This paper focuses on iSSA of results of thedendro-chronological study of a forest of long-lived Tibetan junipers. Fromthis, we determine a median curve of tree growth rates, that is analyzed byiSSA. We obtain a rich set of (pseudo-) periods, from 3.3 yr up to more than1000 years, that compare with the specific spectral signature found in thesunspot and length-of-day time series. We discuss in detail the record from asingle tree that spans almost completely the 357-2000 AD interval. The 90 yrGleissberg, 22 yr and 30 yr components are quite prominent. The Oort, Wolf,Sp\"orer, Maunder and Dalton climate extrema all correspond quite precisely toextrema of the Gleissberg cycle. The well-known Medieval Climate Optimum,Little Ice Age and Modern Climate Optimum all seem to be mainly forced byvariations in the envelope of the Gleissberg cycle. The Gleissberg cycle isstrongly modulated with a period of 500-600 years. The node near a small gap inthe data is very close to the Medieval Climate Optimum. Observations indifferent parts of Earth are in favor of a global extension of the MCO. In thesame way that the Milankovic mathematical theory of climate allows one torelate climate change and length of day, through changes in inclination ofEarth's rotation axis and solar insolation, it is reasonable to propose thatthe set of pseudo-periods that are evidenced in the Tibetan tree ring growthrates simply corresponds to short period Milankovi\'c cycles. The Dulan forestcould be considered as a good candidate for a continuous, global geophysicalobservatory.

A living forest of Tibetan Juniper trees as a new kind of astronomical and geophysical observatory