Tree-Ring Oxygen Isotope Variations in Subalpine Firs from the Western Himalaya Capture Spring Season Temperature Signals

We analyzed the tree-rings ?18O of Abies spectabilis (fir) growing at subalpine treeline ecotone in Magguchatti valley. The valley is located Indian summer monsoon (ISM) dominated region western Himalaya and also receives snow precipitation derived by westerly disturbances (WDs) during winter months. 60 year developed (1960–2019 CE) tree-ring chronology revealed a strong positive correlation with temperature late spring months (February to April). Strong negative correlations are apparent for snowcover, soilmoisture, relative humidity same season. Our findings partly contrast significant results drought indices recorded from other monsoon-dominated regions Himalayas. spatial analyses sea surface temperatures (SSTs) climate parameters showed subdued signals tropical Pacific site, but shift more moisture influx Arabian Sea last two decades. Moreover, North Atlantic Oscillation further justifies strongly captured snowcover weak effect fir trees. A rising trend latter half 20th century elevation taken as important factors controlling source zones.