Large dynamic contributions to tropical cyclone precipitation with increasing sea surface temperature
File(s)
Published version
Author(s)
Yang, Yawen
Toumi, Ralf
Type
Journal Article
Abstract
<jats:title>Abstract</jats:title>
<jats:p>Understanding the relative contribution of dynamic and thermodynamic factors to tropical cyclone (TC) rainfall is an important challenge. This study examines the response of TC precipitation due to increasing sea surface temperatures (SSTs) using convection-permitting model simulations. The sensitivity of key TC rainfall metrics, including the azimuthally averaged maximum precipitation rate were examined. The amount of scaling of precipitation with SST depends on the chosen TC precipitation metric and mostly surpasses the Clausius–Clapeyron (CC) relationship. The azimuthally averaged maximum precipitation rate (Pm) exceeds twice the rate expected under the CC relationship (2CC). By decomposing the scaling rates into thermodynamic and dynamic contributions using a physical diagnostic method, we demonstrate that dynamic changes primarily (about 73%) drive the scaling of Pm. The available moisture plays a much smaller role than expected and scales surprisingly at less than CC. The dynamic contribution is always large for all precipitation metrics. The combination of increased moisture and updrafts enhances moisture convergence, thereby intensifying precipitation and ultimately leading to a super-CC relationship. The ‘exceeding 2CC’ behavior is attributed to the dominance of dynamic effects, particularly enhanced upward motion near the TC inner core. Accurate projections of future changes in TC precipitation therefore depend critically on accurate projections of changes in TC dynamics.</jats:p>
<jats:p>Understanding the relative contribution of dynamic and thermodynamic factors to tropical cyclone (TC) rainfall is an important challenge. This study examines the response of TC precipitation due to increasing sea surface temperatures (SSTs) using convection-permitting model simulations. The sensitivity of key TC rainfall metrics, including the azimuthally averaged maximum precipitation rate were examined. The amount of scaling of precipitation with SST depends on the chosen TC precipitation metric and mostly surpasses the Clausius–Clapeyron (CC) relationship. The azimuthally averaged maximum precipitation rate (Pm) exceeds twice the rate expected under the CC relationship (2CC). By decomposing the scaling rates into thermodynamic and dynamic contributions using a physical diagnostic method, we demonstrate that dynamic changes primarily (about 73%) drive the scaling of Pm. The available moisture plays a much smaller role than expected and scales surprisingly at less than CC. The dynamic contribution is always large for all precipitation metrics. The combination of increased moisture and updrafts enhances moisture convergence, thereby intensifying precipitation and ultimately leading to a super-CC relationship. The ‘exceeding 2CC’ behavior is attributed to the dominance of dynamic effects, particularly enhanced upward motion near the TC inner core. Accurate projections of future changes in TC precipitation therefore depend critically on accurate projections of changes in TC dynamics.</jats:p>
Date Issued
2025-07-01
Date Acceptance
2025-05-12
Citation
Environmental Research Letters, 2025, 20 (7)
ISSN
1748-9326
Publisher
IOP Publishing
Journal / Book Title
Environmental Research Letters
Volume
20
Issue
7
Copyright Statement
© 2025 The Author(s). Published by IOP Publishing Ltd Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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Subjects
attribution
CLIMATE
climate change
Environmental Sciences
Environmental Sciences & Ecology
EXTREMES
INTENSITY
Life Sciences & Biomedicine
Meteorology & Atmospheric Sciences
Physical Sciences
precipitation
SCALE
Science & Technology
SIMULATION
tropical cyclone
Publication Status
Published
Article Number
074013
Date Publish Online
2025-06-03