Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation

Abstract The Madden‐Julian Oscillation (MJO) is a dominant intraseasonal oscillation in the tropics. As MJOs propagate over the Indian Ocean, some of them can be penetrated by fast‐moving equatorial Kelvin waves originating to the west of the MJOs. Through a series of sensitivity experiments, we dem...

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Main Authors: Xingchao Chen, L. Ruby Leung, Zhe Feng
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2025GL116549
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author Xingchao Chen
L. Ruby Leung
Zhe Feng
author_facet Xingchao Chen
L. Ruby Leung
Zhe Feng
author_sort Xingchao Chen
collection DOAJ
description Abstract The Madden‐Julian Oscillation (MJO) is a dominant intraseasonal oscillation in the tropics. As MJOs propagate over the Indian Ocean, some of them can be penetrated by fast‐moving equatorial Kelvin waves originating to the west of the MJOs. Through a series of sensitivity experiments, we demonstrate that these penetrating Kelvin waves can modulate the eastward propagation speed of MJO rainfall. Deep convection in the western MJO rainfall envelope initiates more frequently and produces greater lifetime rainfall when a convectively active Kelvin phase is present, while the opposite occurs during a convectively suppressed Kelvin phase. This alteration in deep convection activity can lead to notable changes in the propagation of the large‐scale MJO rainfall envelope. The modulation of deep convection lifetime rainfall by penetrating Kelvin waves primarily occurs through their impact on deep convection rainfall area, which is closely related to the variations in lower‐tropospheric moisture induced by the Kelvin waves.
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institution OA Journals
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series Geophysical Research Letters
spelling doaj-art-2a44aef7f70b4e34b9686aef0823b7662025-08-20T02:05:13ZengWileyGeophysical Research Letters0094-82761944-80072025-05-015210n/an/a10.1029/2025GL116549Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection ModulationXingchao Chen0L. Ruby Leung1Zhe Feng2Department of Meteorology and Atmospheric Science, and Center for Advanced Data Assimilation and Predictability Techniques The Pennsylvania State University University Park PA USAAtmospheric, Climate, & Earth Sciences Division Pacific Northwest National Laboratory Richland WA USAAtmospheric, Climate, & Earth Sciences Division Pacific Northwest National Laboratory Richland WA USAAbstract The Madden‐Julian Oscillation (MJO) is a dominant intraseasonal oscillation in the tropics. As MJOs propagate over the Indian Ocean, some of them can be penetrated by fast‐moving equatorial Kelvin waves originating to the west of the MJOs. Through a series of sensitivity experiments, we demonstrate that these penetrating Kelvin waves can modulate the eastward propagation speed of MJO rainfall. Deep convection in the western MJO rainfall envelope initiates more frequently and produces greater lifetime rainfall when a convectively active Kelvin phase is present, while the opposite occurs during a convectively suppressed Kelvin phase. This alteration in deep convection activity can lead to notable changes in the propagation of the large‐scale MJO rainfall envelope. The modulation of deep convection lifetime rainfall by penetrating Kelvin waves primarily occurs through their impact on deep convection rainfall area, which is closely related to the variations in lower‐tropospheric moisture induced by the Kelvin waves.https://doi.org/10.1029/2025GL116549MJOKelvin wavesconvection
spellingShingle Xingchao Chen
L. Ruby Leung
Zhe Feng
Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
Geophysical Research Letters
MJO
Kelvin waves
convection
title Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
title_full Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
title_fullStr Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
title_full_unstemmed Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
title_short Impact of Penetrating Kelvin Waves on MJO Rainfall Propagation Through Deep Convection Modulation
title_sort impact of penetrating kelvin waves on mjo rainfall propagation through deep convection modulation
topic MJO
Kelvin waves
convection
url https://doi.org/10.1029/2025GL116549
work_keys_str_mv AT xingchaochen impactofpenetratingkelvinwavesonmjorainfallpropagationthroughdeepconvectionmodulation
AT lrubyleung impactofpenetratingkelvinwavesonmjorainfallpropagationthroughdeepconvectionmodulation
AT zhefeng impactofpenetratingkelvinwavesonmjorainfallpropagationthroughdeepconvectionmodulation