Researchers looked at 3,500-year-long tree ring records from North East Tibet to estimate annual precipitation. They found that recent decades have likely been the wettest on record in this semi-arid region.
Photo: taken by Jialiang Gao on the Tibetan Plateau
The precipitation records have been reconstructed using sub-fossil, archaeological and living juniper tree samples from the north-eastern Tibetan Plateau. They reveal a trend towards wider growth rings, implying moister growing conditions – with the last 50 years seeing increasing amounts of rainfall.
Notable historical dry periods occurred in the 4th Century BC and in the second half of the 15th Century AD.
Dr Tim Osborn from UEA’s Climatic Research Unit said: “Our collaboration with scientists from China has been very fruitful, leading to what is currently the longest tree-ring-width record in the cold and arid north-eastern Tibetan Plateau. Not only is the record very long, it is based on samples from more than 1000 trees, some of which have an individual lifespan of more than 2000 years. These are among the longest-lived trees in the world.”
Not only are these trees long-lived, but they are useful for understanding how climate has changed. The widths of the tree rings show a close correspondence with observations from rain gauges over the last 55 years, such that tree rings in wetter years tend to be wider than tree rings in drier years.
Dr Osborn said: “The most recent few decades have, on average, the widest rings in the 3,500-year record which suggests that this may have been the wettest period, perhaps associated with global warming during the last century. Indeed, over the last two thousand years when the Northern Hemisphere is warm it appears to be wetter in the Mountains of North East Tibet. This suggests that any further large-scale warming might be associated with even greater rainfall in this region – though we note that other factors could also have contributed to the increased ring widths.”
‘A 3500-year tree-ring record of annual precipitation on the north-eastern Tibetan Plateau’ is published in Proceedings of the National Academy of Sciences.
Lisa Horton | EurekAlert!
NASA sees heavy rain in Tropical Cyclone Chan-Hom
02.07.2015 | NASA/Goddard Space Flight Center
Creating a stopwatch for volcanic eruptions
02.07.2015 | Arizona State University
Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.
The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...
New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions
A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...
A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...
The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...
25.06.2015 | Event News
16.06.2015 | Event News
11.06.2015 | Event News
03.07.2015 | Press release
03.07.2015 | Agricultural and Forestry Science
03.07.2015 | Health and Medicine