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Response of the intertropical convergence zone to climate change: location, width and strength

Research output: Contribution to journalArticle


Michael Patrick Byrne, Angeline Pendergrass, Anita Rapp, Kyle Wodzicki

School/Research organisations


Purpose of Review:  The intertropical convergence zone (ITCZ) is a planetary-scale band of heavy precipitation close to the equator. Here, we consider the response of the ITCZ structure to climate change using observations, simulations, and theory. We focus on the substantial yet underappreciated projected changes in ITCZ width and strength, and highlight an emerging conceptual framework for understanding these changes.
Recent Findings: Satellite observations and reanalysis data show a narrowing and strengthening of precipitation in the ITCZ over recent decades in both the Atlantic and Pacific basins, but little change in ITCZ location. Consistent with observations, coupled climate models predict no robust change in the zonal-mean ITCZ location over the twenty-first century. However, the majority of models project a narrowing of the ITCZ and weakening mean ascent. Interestingly, changes in ITCZ width and strength are strongly anti-correlated across models.
Summary:  The ITCZ has narrowed over recent decades yet its location has remained approximately constant. Climate models project further narrowing and a weakening of the average ascent within the ITCZ as the climate continues to warm. Following intense work over the last ten years, the physical mechanisms controlling the ITCZ location are now well understood. The development of complementary theories for ITCZ width and strength is a current research priority. Outstanding challenges include understanding the ITCZ response to past climate changes and over land versus ocean regions, and better constraining all aspects of the ITCZ structure in model projections.


Original languageEnglish
Number of pages16
JournalCurrent Climate Change Reports
VolumeFirst Online
Early online date9 Aug 2018
Publication statusE-pub ahead of print - 9 Aug 2018

    Research areas

  • Intertropical convergence zone, Tropical precipitation, Atmospheric dynamics, Climate change

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