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More Heavy Precipitation in World Urban Regions Captured Through a Two‐Way Subgrid Land‐Atmosphere Coupling Framework in the NCAR CESM2

Authors :
Shu Liu
Yilun Han
Peng Wang
Guang J. Zhang
Bin Wang
Yong Wang
Source :
Geophysical Research Letters, Vol 51, Iss 13, Pp n/a-n/a (2024)
Publication Year :
2024
Publisher :
Wiley, 2024.

Abstract

Abstract Current global climate models (GCMs), limited to grid‐scale land‐atmosphere coupling, cannot represent subgrid urban‐rural precipitation contrasts. This study develops an innovative two‐way subgrid land‐atmosphere coupling framework in the National Center for Atmospheric Research (NCAR) Community Earth System Model version 2 (CESM2) to explicitly resolve land‐atmosphere interaction over subgrid individual land units. Results show that urban heat island (UHI) leads to the urban rainfall effect (URE), which in turn alleviates overestimated UHI over China in CESM2. The URE manifests as a shift toward more heavy precipitation and less light precipitation in world urban areas than in surrounding rural counterparts. This feature is consistent with available observations. In heavy precipitation situations, the UHI promotes atmospheric instability and enhances atmospheric water vapor holding capacity, resulting in more heavy precipitation in urban areas. Conversely, in light precipitation situations, the UHI and decreased evaporation from urban impermeable surfaces diminish atmospheric relative humidity, suppressing light precipitation.

Details

Language :
English
ISSN :
19448007 and 00948276
Volume :
51
Issue :
13
Database :
Directory of Open Access Journals
Journal :
Geophysical Research Letters
Publication Type :
Academic Journal
Accession number :
edsdoj.246eaa4ef6461991c2725f3f6d9cb3
Document Type :
article
Full Text :
https://doi.org/10.1029/2024GL108747