Abstract
Observations of soil moisture (SM) during excess and deficit monsoon seasons between 2000 to 2021 present a unique opportunity to understand the soil water dynamics (SWD) over core monsoon zone (CMZ) of India. This study aims to analyze SWD by investigating the SM variability, SM memory (SMM), and the coupling between surface and subsurface SM levels. Particularly intriguing are instances of concurrent monsoonal extremes, which give rise to complex SWD patterns. Usually, it is noted that a depleted convective activity and persistence of higher temperatures during the pre-monsoon season leads to lower SM, while monsoon rains and post-monsoon showers support the prevalence of higher SM conditions. the long persistent dry spells during deficit monsoon years enhances the Bowen ratio (BR) due to the high sensible heat fluxes. on the other hand, the availability of large latent heat flux during excess monsoon and post-monsoon seasons tend to decrease the BR. This enhancement or reduction in BR is due to evapotranspiration (ET), which influences the SWD by modulating the surface—subsurface SM coupling. the surface and subsurface SM coupling analysis for CMZ exhibits significant distinction in the evolution of wet and dry extremes. SM variations and persistence time scale is used as an indicator of SMM and analyzed for both surface and subsurface SM observation levels. Evidently, subsurface SM exhibits remarkably prolonged memory timescales, approximately twice that of surface SM. Furthermore, we dissect SWD linked to wet and dry extremes by analyzing annual soil water balance at a local site in Pune, India. Our findings reveal that ET and deep drainage on annual scale are modulated largely by number of break events during the monsoon season. in essence, our study underscores the significance of surface-subsurface SM observations in unravelling the intricate tapestry of SWD.
Recommended Citation
M. M. Goswami and M. Mujumdar and B. B. Singh and M. Ingale and N. Ganeshi and M. Ranalkar and T. E. Franz and P. Srivastav and D. Niyogi and R. Krishnan and S. N. Patil, "Understanding the Soil Water Dynamics during Excess and Deficit Rainfall Conditions over the Core Monsoon Zone of India," Environmental Research Letters, vol. 18, no. 11, article no. 114011, IOP Publishing, Nov 2023.
The definitive version is available at https://doi.org/10.1088/1748-9326/acffdf
Department(s)
Biological Sciences
Publication Status
Open Access
Keywords and Phrases
core monsoon zone; evapotranspiration; infiltration; soil moisture; soil moisture memory; soil water dynamics
International Standard Serial Number (ISSN)
1748-9326
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2025 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Nov 2023
Comments
Ministry of Earth Sciences, Grant None