Spring-temperature variations in western Himalaya, India, as reconstructed from tree-rings: AD 1390-1987

Abstract

The Himalayan region plays a very important role in influencing the regional and extra-regional circulation system. Long-term instrumental or proxy climate records for this region are scant, but are essential for a global perspective of climate variability. A 598-year (AD 1390-1987) reconstruction of spring (March-May) temperature has been derived for the first time for the western Himalayan region, India using a well replicated ring-width chronology of Himalayan cedar (Cedrus deodara (D. Don) G. Don). The reconstruction showing annual to multi-year episodes of cool and warm springs is well correlated with the instrumental record of spring temperature for 1876-1987 (r = 0.53, p < 0.001). Prominent large-magnitude century-scale excursions in negative anomalies of spring temperature which might reflect the regional influence of the ‘Little Ice Age’ are not indicated in our data. The seventeenth century experienced monotonically warm springs. Neither recostruction or instrumental data provide evidence of warming during the last few decades of this century which could be attributed to anthropogenic causes. A strong out-of-phase relationship between the instrumental sprin-temperature record over the western Himalayan region and sea-surface temperatures (SSTs) of ensuing months (June-May) over the equatorial Pacific Ocean has been noted. This suggests that temperature responsive tree-ring chronologies from the Himalayan region could also serve as a valuable proxy of the Southern Oscillation.

Early summer temperature reconstruction in the eastern Tibetan plateau since ad 1440 using tree-ring width of Sabina tibetica

“…6). The warm periods 1624-1636, 1650-1668, and 1794-1804 are in good agreement with the March-May temperature reconstruction for the western Himalaya (Yadav et al 1999). The western Calibration period 1954-19801981-20061954-2006Verification period 1981-20061954-1980 The regression equation is in the form of y=a+bx, where y denoted the mean May-June temperature, x equaled the value of the ring-width chronology, a and b are the constants a LOOCV represents leave-one-out cross-validation (Michaelsen 1987) **Stands for the significant level of 0.01 Himalayan record also shows cool conditions identified in our reconstruction during 1440-1454, 1515-1527, and 1922-1937 periods.…”

“…Negative influences of early summer warmth on tree growth were reported for S. przewalskii on the northeastern TP (Gou et al 2008;Liang et al 2010;Liu et al 2006;Shao et al 2010;Sheppard et al 2004;Zhang et al 2003). In the western Himalayas, warm summers also limit the growth of Juniperus polycarpos (Yadav et al 2010), Cedrus deodara (Yadav et al 1997(Yadav et al , 1999Yadav et al 2004) and Abies pindrow (Hughes 1992). In addition, Cai et al (2008) found the limiting effect of May-Jun temperature on tree growth of Pinus tabulaeformis from the southeastern Chinese Loess Plateau.…”

Do Himalayan treelines respond to recent climate change? An evaluation of sensitivity indicators

“…Borgaonkar et al, 1999;Pant et al, 2000;Cook et al, 2003;Ram and Borgaonkar, 2013) and have been used accordingly for temperature and precipitation reconstruction (e.g. Yadav et al, 1997Yadav et al, , 1999Yadav, 2005, 2014;Ram and Borgaonkar, 2014). A significant negative correlation with May temperature has also been detected for Juniperus tibetica on the semiarid southern Tibetan Plateau (He et al, 2013;, a positive relationship, by contrast, for Larix griffithiana in humid Arunachal Pradesh (Chaudhary and Bhattacharyya, 2000).…”

Summer mean temperature variation from 1710–2005 inferred from tree-ring data of the Baimang Snow Mountains, northwestern Yunnan, China

“…The incidence of severe cold in the 1910s-1920s is confirmed by tree-ring records and ice cores from the Tibetan Plateau (Bräuning 2006, Singh et al 2006, Yao et al 2006. The 1930s-1950s period was a relatively prolonged warm period, which was synchronous with a prolonged warm phase in the Himalayan region (Yadav et al 1999, Cook et al 2003 as well as the source region of the Yangtze River (Liang et al 2008) and the western Sichuan Plateau (Li et al 2010). The most noteworthy feature in the 20th century was a clear trend of increasing cold intensity in the 1960s-1980s.…”