The k2p blog

Yet another paper indicating that climate and solar behaviour are related – at least over the Tibetan plateau and at least over the last 1000 years.

Tree ring based precipitation reconstruction in the south slope of the middle Qilian Mountains, northeastern Tibetan Plateau, over the last millennium

by Junyan Sun and Yu Liu,  Chinese Academy of Sciences, Xi’an, China

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, D08108, 11 PP., 2012
doi:10.1029/2011JD017290

Reconstruction of precipitation amounts for the edge of the Tibet Plateau. The bars on the chart depict prominent weak phases of solar activity, which correspond to Om = Oort Minimum; Wm = Wolf Minimum; Sm = Spörer Minimum; Mm = Maunder Minimum; Dm = Dalton Minimum). Figure from: Sun & Liu (2012).

Geologist Dr. Sebastian Lüning and chemist Prof. Fritz Vahrenholt have written a summary of this paper (in German), and this translation is from P Gosselin at NoTricksZone

New Study of the Tibet Plateau: Whenever Solar Activity is Weak, the Rains Disappear
By Sebastian Lüning and Fritz Vahrenholt

The Tibet Plateau is at 3000 to 5000 meters elevation and is the highest and (most) expansive high plateau on Earth. Therefore it reacts sensitively to climate changes. Junyan Sun and Yu Liu of the Chinese Academy of Sciences studied tree rings in the northwest plateau edge from two living 1000 year old trees. Tree growth in the area of study is particularly sensitive to the amount of precipitation.

Both scientists were able to reconstruct the distinct precipitation fluctuations occurring over the last 1000 years. The corresponding wet and dry periods each lasted some decades. A comparison to the other climate reconstructions coming from the same region shows great similarities in moisture development and that we are dealing with a representative regional climate signal. There were pronounced periods of droughts from 1092-1172, 1441-1517 and 1564–1730. Especially the Great Drought of 1441-1517 is mentioned in numerous historical documents and catastrophe reports. The Great Drought occurred during a weak period of solar activity, the so-called Spörer Minimum, which occurred from 1420 to 1570.

Interestingly, almost all other periods of drought occurred during times of solar minima, among them the Oort Minimum, Wolf Minimum, Maunder Minimum and Dalton Minimum (see Figure 1 above). Every time the sun goes into a slumber for a few decades, the rains on the Tibet Plateau stay away. A frequency analysis of precipitation curves also delivers evidence on solar cycles. Here the Gleissberg Cycle (60-120 year period) and the Suess/de Vries Cycle (180-220 years) are seen in the datasets.

The study once again documents the enormous importance of solar activity fluctuations on the development of climate.

Tags: Dalton minimum, grand solar minima, Maunder Minimum, solar effects on climate, Solar variation, Spörer Minimum, Tibetan Plateau

This entry was posted on May 14, 2012 at 1:48 pm and is filed under Climate, Solar science. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.