Arindam Chakraborty
Professor
Centre for Atmospheric and Oceanic Sciences, &
Divecha Centre for Climate Change (Associated)
Indian Institue of Science
Bengaluru, KA, India.

Email: arch -at- iisc.ac.in
Phone: +91-80-2293-3074
Google Scholar Profile
ResearchGate Profile
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Research Interests: Theory of Monsoons and Onset, Tropical Climate and Teleconnection, El Nino-Southern Oscillation, Extreme Events, Land-Atmosphere Interaction, Climate Models, Seasonal Prediction, AI/ML in Climate.
Research Highlights
    Book on South Asian Summer Monsoon
    A new book on the South Asian Summer Monsoon details our current understanding of its theory, variability from synoptic to decadal scales, forecasting aspects, and vision to future research. We hope that this book will be useful to students, researchers, forecasters, and application builders whos work relates to monsoons of the south Asian region.

    Recent Shift of Phase of Diurnal Cycle of Indian Summer Monsoon Rainfall
    Weather and climate variations are most noticeable on the diurnal timescale, either in sync with or offset from the solar radiation reaching the top of the atmosphere. These variations in the energy budget, especially related to moist convection, interact with the broader climate system. Using hourly station data from across India, we demonstrate that the timing of the rainfall diurnal cycle during the summer monsoon season has shifted consistently across different regions in recent decades (1992–2014) compared to earlier periods (1969–1991). While much of central, northern, and southern peninsular India, which represents about 55% of the stations, has seen a delay in the rainfall phase, smaller regions like northeast and northwest India have experienced an earlier phase. See here for details.
    Reference: Chutia et al. (2025).

    Possible Mechanisms behind Dominant Modes of Seasonal Cycle of Rainfall over India
    Observations indicate that rainfall during the onset phase of the monsoon (June) is not correlated with rainfall in the post-onset phase (July-September). For the first time, this study establishes a connection between inter-annual and monthly variations in rainfall without assuming any of the intra-seasonal features typically observed during the monsoon, such as onset, intra-seasonal oscillations, synoptic variabilities, and extremes. Inter-annual variations lead to perturbations to the mean seasonal cycle, which in turn results in monthly variations of rainfall on top of the mean seasonal cycle. This study aims to understand the governing mechanisms behind these monthly variations of rainfall every year. The analyses reveal that June rainfall, which is related to the rapid or slow progress of the monsoon onset, is primarily influenced by the normal or slow phase transition of the Madden-Julian Oscillation, along with prevailing background conditions of precipitable water. Conversely, the rainfall for the remainder of the season is mainly governed by the phase of the El Niño Southern Oscillation through anomalous moisture flux convergence. See here for details.
    Reference: Bhattacharyya and Chakraborty(2025).

    ENSO Transition Mode (ETM)
    The ENSO transition mode (ETM) is a climate mode of the southern hemisphere Indo-Pacific Ocean domain, especially prominent during boreal spring. The positive phase of this mode is characterized by a zonal dipole of surface pressure over the southern Pacific Ocean with an increase in pressure toward the east. It creates a surface wind pattern that helps increase the eastern equatorial Pacific sea surface temperature (SST0 from boreal winter to summer. In other words, a positive phase of ETM helps develop a positive phase of ENSO (El Nino) or helps weaken a negative phase of ENSO (La Nina). ETM forcing is most effective in modulating such transition at the multidecadal time scales (~50 years). See here for details.
    Reference: Srivastava et al. (2024) , Srivastava et al. (2025).

    Indian and Sahelian Summer Monsoon: Coherence and Mechanism
    The Indian and Sahelian summer monsoons are critical components of the global monsoon system, shaping climate variability and livelihoods across Asia and Africa. While both are linked to the Intertropical Convergence Zone, they retain strong regional identities and exhibit pronounced interannual variability. In this work, we explore how these two monsoon systems coevolve and interact using long-term rainfall observations. Using long term running correlation we highlight a strengthening connection between the Indian and Sahelian monsoons in recent decades and examine the physical mechanisms—spanning intraseasonal dynamics, large-scale circulation, and moisture variability—that underpin this emerging linkage, with implications for improved monsoon prediction. See here for details.
    Reference: Bordoloi et al. (2025) .
Journal Publications
Books/Chapters and Popular Articles
Opportunity

Students are admitted through normal procedure of IISc. Visit https://www.iisc.ac.in/admissions/ for details.

If you are looking for a PostDoc position, IISc has advertised for CV Raman Postdoc Fellowship. Details are here.

If you are looking for an intership, you may want to apply through the Indian Academy of Sciences Summer Fellowship Program.