The study reveals significant rise in air temperature in the northwest Himalayan (NWH) region by about 1.6°C in the last century, with winters warming at a faster rate. The diurnal temperature range (DTR) has also shown a significantly increasing trend. This appears to be due to rise in both the maximum as well as minimum temperatures, with the maximum increasing much more rapidly. The results are in contrast to the findings in the Alps and Rockies where the minimum temperatures have increased at an elevated rate. Conforming to the global trends, the study confirms episodes of strong warming and cooling in the NWH in the last century. Real warming appears to have started from late-1960s and highest rate of increase was experienced in the last two decades. The study also shows teleconnections between temperatures and an epochal behaviour of the precipitation till late1960s. These teleconnections seem to have weakened gradually since then and rapidly in the post-1991 period, indicating the waning effect of the natural forcings in this period.

Using available instrumental records, this paper examines the variation of precipitation from 1866 to 2006 in the northwestern Himalaya (NWH). The study indicates no trend in the winter precipitation but significant decreasing trend in the monsoon precipitation during the study period. Periodicities on a multi-decadal scale (29-34 years and 58-64 years) obtained in power spectrum analyses point towards epochal behaviour in the precipitation series. Analyses of the temperature data show significant increasing trends in annual temperature in all three stations in the NWH during the data period. Warming effect is particularly noteworthy during the winter season. Negative relationships between mean winter air temperature and snowfall amounts recorded at different meteorological stations in this period reveal strong effect of rising temperatures on the decreasing snowfall component in total winter precipitation, reducing effective duration of winter on the windward side of the Pir Panjal Himalayan Range.The study also shows influence of global teleconnections [North-Atlantic Oscillation (NAO) during winter months and Southern Oscillation Index (SOI) during the monsoon months] on precipitation fluctuations in the NWH. The teleconnections that appear to exist between the precipitation and the temperature until the late 1960s seem to have weakened considerably in the last three decades. This may be ascribed to the diminishing effect of the natural factors such as quasi-biennial oscillations (QBO), El Niño Southern Oscillations (ENSO), double sunspot cycles (Hale), etc., in this period. Role of increasing concentration of greenhouse gases in the atmosphere cannot be ruled out.

The hyd rological method is used to compute the m ass ba la nce ofSiachen Gl acier in th e Nubra Valley, K a rakora m Him a laya, India. The m ethod was chosen because of its suitability in rugged terra in. Analysis of precipitati on ? ata from th e glacier as a ~unc­ tion of altitude shows a power-law rel ationship. Accumulal10n eStimates based on thls re-lati onship show good ag reem ent with th e recorded precipitati on. Th e di scha rge d ata fr om the glacier sho w high runoff in th e abl ati on seasons of 198 6~ 87,. 1987 ~ 88, 1 989~ 9 ~ a nd 1 99 0~9 1. The m ass-balance calculations for th ese years a re negatI ve, the lowest bell1g III 1 99 0~9 1 (~ 10 84 mm). Positive m ass balance in 1 988~89 (~35 8mm) is attribu ted to e~ m­ pa rari vely heavy winter snowfa ll a mounts a nd compa ratively I? w t e l~lp e ratures dUrI.ng the ablation seaso n. Significantly lower runoff was measured dUrIng thI s season. N e~a t l ve mass-balance va lues during 1 98 9 ~ 9 0 a nd 1 990~9 1 a re a result of comparatI vely d ry wll1ters a nd compa rati vely wa rm abl ation periods, with m onthly mean a ir temperatures 1.4~ 5.l QC higher at the beginning of the abl ati on seaso n Gune a ndJuly) tha n the mean of the las t 5 yea rs.

Understanding snowfall variations in high‐elevation cold arid regions of the western Himalaya is important as snowmelt water is the main source of water to meet the scores of socioeconomic needs. The ground‐based observational data, though limited to the last two decades, show decreasing snowfall, raising the concern of looming water scarcity in the region. The tree‐ring data of Himalayan cedar from a network of six moisture‐stressed sites, where snowmelt water is the sole source of soil moisture for tree growth, were used to develop the November–April snow water equivalent (SWE) extending back to A.D. 1460. The reconstruction revealed persistent severe droughts in the 1780s followed by the 1480s and relatively lesser magnitude droughts in the 1540s–1560s, 1740s, and early twentieth century. The pluvial conditions observed in 1948–1958 and 1986–1996 stand out over any other period of such duration. The SWE reconstruction revealed large‐scale spatial coherence with the corresponding month's Palmer Drought Severity Index over the western Himalayan region. Significant relationship observed between SWE reconstruction and January–March Chenab River flow revealed its potential utility in understanding water resource availability in the long‐term perspective.

ABSTRACT. The hyd rological method is used to compute the m ass ba la nce ofSiachen Gl acier in th e Nubra Valley, K a rakora m Him a laya, India. The m ethod was chosen because of its suitability in rugged terra in. Analysis of precipitati on ? ata from th e glacier as a ~unc tion of altitude shows a power-law rel ationship. Accumulal10n eStimates based on thls relati onship show good ag reem ent with th e recorded precipitati on. Th e di scha rge d ata fr om the glacier sho w high runoff in th e abl ati on seasons of 198 6~87,. 1987~88, 1 989~9~ a nd 1 99 0~9 1. The m ass-balance calculations for th ese years a re negatI ve, the lowest bell1g III 1 99 0~9 1 (~10 84 mm ). Positive m ass balance in 1 988~89 (~35 8mm ) is attribu ted to e~m pa rari vely heavy winter snowfa ll a mounts a nd compa ratively I? w t e l~lp e ratures dUrI.ng the ablation seaso n. Significantly lower runoff was measured dUrIng thI s season. N e~a t l ve mass-balance va lues during 1 98 9~9 0 a nd 1 990~9 1 a re a result of comparatI vely d ry wll1ters a nd compa rati vely wa rm abl ation periods, with m onthly mean a ir temperatures 1.4~5.l QC higher at the beginning of the abl ati on seaso n Gune a ndJuly) tha n the mean of the las t 5 yea rs.