Proxy Response Heterogeneity to the Indian Monsoon During Last Millennium in the Himalayan Region

Abstract

We reviewed the available climate records for the past 2 millennia based on the analyzed sediment and speleothem archives from different regions of South Asia. Speleothem records from the core-monsoon regions of the Indian sub-continent have revealed the Little Ice Age (LIA) as a climatically dry phase, whereas the same from the western and central Himalaya recorded LIA as wet. Moreover, the sediment-derived vegetation proxy records [pollen-spores and stable organic carbon isotope (δ13Corg)] from the western Himalaya also reported LIA as a dry phase. Heterogeneous results by different proxies during LIA enhanced our interest to understand the response of the proxies toward the primary precipitation sources, Indian summer monsoon (ISM) and winter westerly disturbances (WDs), over the Himalaya. We emphasize that in the Himalayan region, the vegetation predominantly responds to the ISM dynamics, whereas speleothem also captures the WD effect.

Impact of Long‐Distance Interaction Indicator (Monsoon Indices) on Spatio‐Temporal Variability of Precipitation Over the Mahanadi River Basin

“…The dynamic construction of monsoon indices is made using the relationship between circulation and convection in the tropics (Zhang et al, 2022). Past literature has confirmed the influence of ENSO on ISMR but has also augmented the variability of monsoon indices and the change in the dominant monsoon index on IMSR (Das et al, 2020;Hussain et al, 2022;Rehana et al, 2022;Reshma et al, 2021;Roy et al, 2017Roy et al, , 2019Roy et al, , 2022. The present study considers the monsoon index surrounding India, which includes ISMI, SASMI, EASMI, and WNPMI, to investigate long-distance interaction with ISMR.…”

“…Researchers, consultants, and hydrologists have associated different hydrometeorological components with large‐scale climate indicators to study their consequences. Also, the literature on large‐scale climatic indicators has recorded significant heterogeneity over multi‐scale systems (Lee & Bódai, 2021; Reshma et al., 2021; Roy et al., 2022). Hence, understanding the dynamics of long‐distance interactions of large‐scale climatic indicators with ISMR is the basic objective of this study.…”