The role of the background meridional moisture gradient on the propagation of the MJO over the maritime continent

Daehyun Kang, Daehyun Kim, Min Seop Ahn, Soon Il An

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


This study investigates the role of the background meridional moisture gradient (MMG) on the propagation of the Madden–Julian oscillation (MJO) across the Maritime Continent (MC) region. It is found that the interannual variability of the seasonal mean MMG over the southern MC area is associated with the meridional expansion and contraction of the moist area in the vicinity of the MC. Sea surface temperature anomalies associated with relatively high and low seasonal mean MMG exhibit patterns that resemble those of El Niño–Southern Oscillation. By contrasting the years with anomalously low and high MMG, we show that MJO propagation through the MC is enhanced (suppressed) in years with higher (lower) seasonal mean MMG, although the effect is less robust when MMG anomalies are weak. Column-integrated moisture budget analysis further shows that sufficiently large MMG anomalies affect MJO activity by modulating the meridional advection of the mean moisture via MJO wind anomalies. Our results suggest that the background moisture distribution has a strong control over the propagation characteristics of the MJO in the MC region.

Original languageEnglish
Pages (from-to)6565-6581
Number of pages17
JournalJournal of Climate
Issue number16
Publication statusPublished - 2021 Aug 15

Bibliographical note

Funding Information:
Acknowledgments. We thank the anonymous reviewers for their constructive comments on an earlier version of the manuscript. This work was funded by the NOAA CVP program (NA18OAR4310300), DOE RGMA program (DESC0016223), the NASA MAP program (80NSSC17K0227) and KMA R&D Program (KMI2021-01210). S.-I. An was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (NRF-2018R1A5A1024958) and the LG Yonam Foundation of Korea. D. Kang was supported by Sejong Science Fellowship funded by the National Research Foundation of Korea (NRF-2021R1C1C2004621). Work of the LLNL-affiliated author (MSA) was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and their efforts were supported by the Regional and Global Climate Modeling Program of the United States Department of Energy’s Office of Science.

Publisher Copyright:
Ó 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy

All Science Journal Classification (ASJC) codes

  • Atmospheric Science


Dive into the research topics of 'The role of the background meridional moisture gradient on the propagation of the MJO over the maritime continent'. Together they form a unique fingerprint.

Cite this