Increasing aridity over the past 223 years in the Nepal Himalaya inferred from a tree-ring δ18O chronology

Masaki Sano, R. Ramesh, MS Sheshshayee, R. Sukumar

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

A tree-ring δ18O chronology of Abies spectabilis from the Nepal Himalaya was established to study hydroclimate in the summer monsoon season over the past 223 years (ad 1778-2000). Response function analysis with ambient climatic records revealed that tree-ring δ18O was primarily controlled by the amount of precipitation and relative humidity during the monsoon season (June-September). Since tree-ring δ18O was simultaneously correlated with temperature, drought history in the monsoon season was reconstructed by calibrating against the Palmer Drought Severity Index (PDSI). Our reconstruction that accounts for 33.7% of the PDSI variance shows a decreasing trend of precipitation/moisture over the past two centuries, and reduction of monsoon activity can be found across different proxy records from the Himalaya and Tibet. Spatial correlation analysis with global sea surface temperatures suggests that the tropical oceans play a role in modulating hydroclimate in the Nepal Himalaya. Although the dynamic mechanisms of the weakening trend of monsoon intensity still remain to be analyzed, rising sea surface temperatures over the tropical Pacific and Indian Ocean could be responsible for the reduction of summer monsoon.

Original languageEnglish
Pages (from-to)809-817
Number of pages9
JournalHolocene
Volume22
Issue number7
DOIs
Publication statusPublished - 2012 Jul
Externally publishedYes

Fingerprint

aridity
tree ring
chronology
monsoon
drought
sea surface temperature
summer
Tree-ring Chronologies
Temperature
Nepal
Drought
relative humidity
moisture
Tropical
Tree Rings
Summer
ocean
history
temperature

Keywords

  • climate reconstruction
  • dendrochronology
  • Nepal
  • oxygen isotope ratios
  • Palmer Drought Severity Index
  • summer monsoon

ASJC Scopus subject areas

  • Global and Planetary Change
  • Archaeology
  • Ecology
  • Earth-Surface Processes
  • Palaeontology

Cite this

Increasing aridity over the past 223 years in the Nepal Himalaya inferred from a tree-ring δ18O chronology. / Sano, Masaki; Ramesh, R.; Sheshshayee, MS; Sukumar, R.

In: Holocene, Vol. 22, No. 7, 07.2012, p. 809-817.

Research output: Contribution to journalArticle

Sano, Masaki ; Ramesh, R. ; Sheshshayee, MS ; Sukumar, R. / Increasing aridity over the past 223 years in the Nepal Himalaya inferred from a tree-ring δ18O chronology. In: Holocene. 2012 ; Vol. 22, No. 7. pp. 809-817.
@article{b9c14f2591e747e385e4757eda03c30c,
title = "Increasing aridity over the past 223 years in the Nepal Himalaya inferred from a tree-ring δ18O chronology",
abstract = "A tree-ring δ18O chronology of Abies spectabilis from the Nepal Himalaya was established to study hydroclimate in the summer monsoon season over the past 223 years (ad 1778-2000). Response function analysis with ambient climatic records revealed that tree-ring δ18O was primarily controlled by the amount of precipitation and relative humidity during the monsoon season (June-September). Since tree-ring δ18O was simultaneously correlated with temperature, drought history in the monsoon season was reconstructed by calibrating against the Palmer Drought Severity Index (PDSI). Our reconstruction that accounts for 33.7{\%} of the PDSI variance shows a decreasing trend of precipitation/moisture over the past two centuries, and reduction of monsoon activity can be found across different proxy records from the Himalaya and Tibet. Spatial correlation analysis with global sea surface temperatures suggests that the tropical oceans play a role in modulating hydroclimate in the Nepal Himalaya. Although the dynamic mechanisms of the weakening trend of monsoon intensity still remain to be analyzed, rising sea surface temperatures over the tropical Pacific and Indian Ocean could be responsible for the reduction of summer monsoon.",
keywords = "climate reconstruction, dendrochronology, Nepal, oxygen isotope ratios, Palmer Drought Severity Index, summer monsoon",
author = "Masaki Sano and R. Ramesh and MS Sheshshayee and R. Sukumar",
year = "2012",
month = "7",
doi = "10.1177/0959683611430338",
language = "English",
volume = "22",
pages = "809--817",
journal = "Holocene",
issn = "0959-6836",
publisher = "SAGE Publications Ltd",
number = "7",

}

TY - JOUR

T1 - Increasing aridity over the past 223 years in the Nepal Himalaya inferred from a tree-ring δ18O chronology

AU - Sano, Masaki

AU - Ramesh, R.

AU - Sheshshayee, MS

AU - Sukumar, R.

PY - 2012/7

Y1 - 2012/7

N2 - A tree-ring δ18O chronology of Abies spectabilis from the Nepal Himalaya was established to study hydroclimate in the summer monsoon season over the past 223 years (ad 1778-2000). Response function analysis with ambient climatic records revealed that tree-ring δ18O was primarily controlled by the amount of precipitation and relative humidity during the monsoon season (June-September). Since tree-ring δ18O was simultaneously correlated with temperature, drought history in the monsoon season was reconstructed by calibrating against the Palmer Drought Severity Index (PDSI). Our reconstruction that accounts for 33.7% of the PDSI variance shows a decreasing trend of precipitation/moisture over the past two centuries, and reduction of monsoon activity can be found across different proxy records from the Himalaya and Tibet. Spatial correlation analysis with global sea surface temperatures suggests that the tropical oceans play a role in modulating hydroclimate in the Nepal Himalaya. Although the dynamic mechanisms of the weakening trend of monsoon intensity still remain to be analyzed, rising sea surface temperatures over the tropical Pacific and Indian Ocean could be responsible for the reduction of summer monsoon.

AB - A tree-ring δ18O chronology of Abies spectabilis from the Nepal Himalaya was established to study hydroclimate in the summer monsoon season over the past 223 years (ad 1778-2000). Response function analysis with ambient climatic records revealed that tree-ring δ18O was primarily controlled by the amount of precipitation and relative humidity during the monsoon season (June-September). Since tree-ring δ18O was simultaneously correlated with temperature, drought history in the monsoon season was reconstructed by calibrating against the Palmer Drought Severity Index (PDSI). Our reconstruction that accounts for 33.7% of the PDSI variance shows a decreasing trend of precipitation/moisture over the past two centuries, and reduction of monsoon activity can be found across different proxy records from the Himalaya and Tibet. Spatial correlation analysis with global sea surface temperatures suggests that the tropical oceans play a role in modulating hydroclimate in the Nepal Himalaya. Although the dynamic mechanisms of the weakening trend of monsoon intensity still remain to be analyzed, rising sea surface temperatures over the tropical Pacific and Indian Ocean could be responsible for the reduction of summer monsoon.

KW - climate reconstruction

KW - dendrochronology

KW - Nepal

KW - oxygen isotope ratios

KW - Palmer Drought Severity Index

KW - summer monsoon

UR - http://www.scopus.com/inward/record.url?scp=84861759582&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861759582&partnerID=8YFLogxK

U2 - 10.1177/0959683611430338

DO - 10.1177/0959683611430338

M3 - Article

AN - SCOPUS:84861759582

VL - 22

SP - 809

EP - 817

JO - Holocene

JF - Holocene

SN - 0959-6836

IS - 7

ER -