Wache, Bhutan 269 Year Tree Ring Oxygen Isotope Data Sano, M.; Tshering, P.; Komori, J.; Fujita, K.; Xu, C.; Nakatsuka, T. Sano, M. Tshering, P. Komori, J. Fujita, K. Xu, C. Nakatsuka, T. Monsoon LAGR Larix griffithiana (Lindl. & Gord.) Carr. Himalayan larch earth science/paleoclimate/tree ring (delta 18O,alpha cellulose,null,per mil VSMOW,null,tree ring,null,null,N,null) earth science/paleoclimate/tree ring (age,null,null,year Common Era,null,tree ring,null,null,N,null) earth science/paleoclimate/tree-ring (Wache>LATITUDE 27.983>LONGITUDE 90) We developed a 50-year tree ring d18O chronology for each of three tree species (Juniperus indica, Larix griffithii, and Picea spinulosa) using a total of 12 trees (four trees per species) from the Bhutan Himalaya. Despite originating from different species sampled at two different altitudes, the d18O chronologies are highly correlated with one another (r = 0.76-0.89). Response analyses reveal that tree ring d18O values are controlled mainly by summer precipitation, irrespective of species. Based on these results, a robust 269-year d18O chronology was established to reconstruct the amount of May-September precipitation based on data from four larch trees. Our tree ring d18O data show significant correlations with those from other regions of the Himalaya and the Tibetan Plateau, indicating that common signals related to monsoon activity are recorded in the data. However, at centennial timescales, our data from Bhutan show normal conditions during the 20th century, whereas records from sites in western Nepal and the southern/eastern Tibetan Plateau show weakening trends in monsoon intensity during the last 100-200 years; the weakening trends may be the result of a reduction in the meridional sea surface temperature gradient in the Indian Ocean during this time. At continental scales, the tree ring records show that areas more from ocean basins are particularly sensitive to reduced monsoon circulation. Correlation analyses suggest that the El Niño-Southern Oscillation (ENSO) plays an important role in modulating summer precipitation. However, the teleconnected relationship disappears during the period 1951-1970, coinciding with a negative phase of the Pacific Decadal Oscillation (PDO), implying interdecadal modulation of the PDO on the influence of the ENSO on precipitation in Bhutan. STUDY NOTES: Larix griffithii tree-ring oxygen isotope (d18O) data from Wache, Lunana, Bhutan, for the past 269 years. IITRDB27 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Sano, M. Investigator : Tshering, P. Investigator : Komori, J. Investigator : Fujita, K. Investigator : Xu, C. Investigator : Nakatsuka, T. 2017-08-23 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/22548 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/asia/bhutan/wache2013d18o.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/asia/bhutan/wache2013d18o.txt English https://www.ncdc.noaa.gov/paleo/study/22548 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/asia/bhutan/wache2013d18o.txt Masaki Sano, Phuntsho Tshering, Jiro Komori, Koji Fujita, Chenxi Xu, Takeshi Nakatsuka2013May-September precipitation in the Bhutan Himalaya since 1743 as reconstructed from tree ring cellulose d18OJournal of Geophysical Research: Atmospheres118158399-841010.1002/jgrd.50664http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50664/full START YEAR: 1743 AD * END YEAR: 2011 AD 90 27.983 90 27.983