The Indian Summer Monsoon is crucial for agriculture and the economy in India, providing most of the region’s annual rainfall. Understanding which factors influence the monsoon, especially its variability within a single season, is vital for better weather predictions. A recent study, published in Geophysical Research Letters, identified and quantified the tropical atmospheric drivers affecting the monsoon over the past four decades. Researchers found that the tropical western Pacific increasingly impacts the Indian Summer Monsoon, while the monsoon’s own self-regulating processes have weakened.
The results showed that changes in atmospheric waves known as Rossby waves, particularly in the tropical western Pacific, have become more influential. This shift suggests global warming could be amplifying unusual weather patterns in the western Pacific, which then propagate westward to affect the monsoon. These findings enhance our understanding of monsoon variability and highlight the need for better prediction models, which are crucial for managing water resources and planning for agriculture in India. The research team included Aneesh Subramanian, a researcher at the University of Colorado, Boulder who is funded by the Climate Program Office’s Climate Variability & Predictability (CVP) program to contribute to pre-field modeling research building toward the goals of the Tropical Pacific Observing System (TPOS). This work contributes to an overarching effort to enhance and redesign international observations of the tropical Pacific, which includes the upcoming TPOS Equatorial Pacific Experiment (TEPEX).
For more information, contact Clara Deck.
Image credit: NASA
