Recent Wetting and Glacier Expansion in the Northwest Himalaya and Karakoram

A reconstruction of annual to multi‐decadal precipitation based on ring‐width of Cedrus deodara (Himalayan cedar or deodar) was carried out in the Lidder (Liddar) Valley, Kashmir Himalaya. A composite tree‐ring chronology demonstrated a significant direct relationship with April–June precipitation. A modified version of point‐by‐point regression methodology was used to reconstruct April–June precipitation since 1723 C.E. This reconstruction accounts for 40% of the total variance of the actual precipitation in the calibration period. The reconstruction shows a prolonged decadal dry period between 1822 and 1887 C.E., the driest period in the reconstruction. The wettest period occurred during the early 19th century and latter part of the 20th century. Extreme dry and wet events have been identified in the reconstruction on the basis of percentile distribution. The reconstruction was compared with documented extreme flood, famines and drought events in Kashmir Valley occurring in those 288 years. The composite 500 mb height‐anomaly maps suggest the prospect to study the long‐term atmospheric circulation variability over the Kashmir Valley and surrounding region using tree‐ring data. The impact of westerlies in the precipitation patterns was also evident in analysis of composite 500 mb height anomaly. Furthermore, the reconstruction was validated through comparison with independent records and spatial correlation with gridded precipitation and drought.

Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

“…() and 1970–1971 in Yadav et al . ()) and wet years and periods (1817, 1891 in Hughes (); 1781, 1799, 1813–14 and 1859 in Borgaonkar et al . () and 1994, 1996, 1998 in Singh et al .…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Precipitation reconstruction for the Lidder Valley, Kashmir Himalaya using tree‐rings of Cedrus deodara

Shah

Pandey

Mehrotra

2018

Rainfall reconstruction for the Karakoram region in Pakistan since 1540 CE reveals out‐of‐phase relationship in rainfall between the southern and northern slopes of the Hindukush‐Karakorum‐Western Himalaya region

Khan

Chen

Ahmed

et al. 2019

Climate change has influenced the glaciers and water resources in the Hindukush‐Karakorum‐Himalaya region. The relatively short instrumental record of northern Pakistan makes long‐term climate change assessments difficult. In this paper, tree‐ring width chronologies were developed from two stands of spruce species (Picea smithiana) in the Karakoram region of northern Pakistan. The results of the correlation analysis revealed that tree‐ring growth of spruce was limited by annual (June–May) precipitation. Based on the regional chronology, we developed an annual precipitation reconstruction for the period 1540–2016 CE. The precipitation reconstruction equation accounts for 40% of the regional precipitation variance during the instrumental period 1946–2016. Dry episodes with rainfall below the 477‐year average occurred from 1569 to 1577, 1598 to 1612, 1621 to 1621, 1638 to 1654, 1673 to 1680, 1697 to 1720, 1728 to 1739, 1753 to 1761, 1777 to 1793, 1801 to 1840, 1860 to 1874, 1914 to 1932, 1960 to 1985, 1998 to 2011. Wet episodes occurred from 1540 to 1568, 1578 to 1597, 1613 to 1620, 1632 to 1637, 1655 to 1672, 1681 to 1696, 1721 to 1727, 1740 to 1752, 1762 to 1776, 1794 to 1800, 1841 to 1859, 1875 to 1913, 1933 to 1959, 1986 to 1997. Furthermore, the results of spatial correlation analyses show that the reconstructed precipitation represents the regional precipitation variations for northern Pakistan and nearby high‐altitude mountains. The out‐of‐phase relationship in tree‐ring records of the Karakoram region and surrounding areas suggests that the Karakoram was under the control of large‐scale ocean–atmosphere–land circulations on a decadal timescale in the past centuries. In addition, by the comparison between the precipitation reconstruction and the instrumental data, we found that the drought risk of Karakoram has increased in the past 70 years and that extreme events are likely to become more severe and more frequent under the backdrop of climatic warming.

Dynamical and thermodynamical interactions in daily precipitation regimes in the Western Himalayas

Battula

Siems

Mondal

2022

The mechanisms by which moisture interacts with the Himalayas largely determine the amount of precipitation in Himalayan basins. While many recent studies have focused on mechanisms of independent precipitation events, climatological studies that are essential for a complete understanding of precipitation-generating mechanisms are limited. This work presents synoptic regimes, which produced precipitation across all seasons in the Western Himalayas (WH) from 2000 to 2018. Using the k-means clustering algorithm, seven clusters are employed to define relatively mild, moderate and wet regimes, showing distinct seasonality and a synoptic meteorology. We found positive precipitation anomalies at lower elevations in monsoonal regimes (M1, M2 and M3) but at higher elevations in winter (W1 and W2) and transitional regimes (T1 and T2). Moist monsoonal regimes are associated with dynamical interactions between low-level tropical cyclonic circulations and mid-level subtropical troughs. Synchronous primary and secondary cyclonic circulations facilitate tropical moisture influx and obstruct the further northward movement of cyclonic circulations, which results in large magnitudes of precipitation at lower elevations in monsoonal regimes. On the other hand, winter regimes exhibit intense western disturbances, which enable orographic ascent of tropical moisture towards higher elevations. Despite weaker dynamical interactions, a stronger thermodynamical instability and a steeper terrain gradient trigger deep convection at higher elevations in transitional regimes.Overall, monsoonal regimes account for 52% of rainy days, whereas winter and transitional regimes account for 20 and 28%, respectively. We present a methodology that identifies hotspots of anomalous precipitation over vulnerable higher elevations by tracking atmospheric variables in Delhi. Our results illustrate the dynamical and thermodynamical interactions responsible for precipitation and highlight the significant contribution from nonmonsoonal regimes to the precipitation across higher elevations in the WH.