The GLACE-Hydrology Experiment: Effects of Land–Atmosphere Coupling on Precipitation Change and Monsoonal Circulations
Journal
Journal of Climate
Journal Volume
39
Journal Issue
3
Start Page
805
End Page
816
ISSN
0894-8755
1520-0442
Date Issued
2026-02-01
Author(s)
Abstract
Land–atmosphere coupling is an important component of climate dynamics in numerical models, influencing regional climate patterns such as precipitation and monsoonal circulation. This study investigates the role of land–atmosphere interactions in modulating rainfall and monsoon intensity by comparing coupled and uncoupled simulations using the Community Earth System Model (CESM). Coupled simulations generally produce higher temperatures and reduced precipitation across most land regions, whereas monsoon regions experience increased precipitation due to enhanced vertical motion and strengthened monsoonal circulation. Through moisture budget analysis and moist static energy (MSE) profiling, we identify the mechanisms driving these changes, including intensified horizontal moisture advection and a stronger dynamic component over the Indian subcontinent. These results indicate that increases in midtropospheric moisture and changes in atmospheric stability are the key factors enhancing vertical motion and precipitation. In this study, we integrate MSE profiles with the Webster–Yang monsoon index, providing a novel framework for assessing how land–atmosphere interactions modulate monsoon dynamics. Understanding these feedbacks is essential for improving climate model simulations in regions highly sensitive to monsoon variability, with important implications for water resources and agricultural productivity. SIGNIFICANCE STATEMENT: This study examines how land and atmosphere interactions affect rainfall in four regions: central North America, southern Europe, the Sahel, and India. In most regions, higher temperatures lead to less rainfall, but in India, stronger circulation brings more moisture and induces more rainfall. This is due to the enhanced temperature difference between land and ocean, which strengthens the monsoon circulation. The research shows that land–atmosphere coupling is crucial for understanding changes in precipitation, especially in monsoon regions. This helps improve climate models for predicting future climate changes. Ó 2026 American Meteorological Society. This published article is licensed under the terms of the default AMS reuse license. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
Subjects
Atmosphere-land interaction
Climate variability
Land surface
Land surface model
Monsoons
Publisher
American Meteorological Society
Type
journal article