This study investigates the occurrence of tropical cyclones in the North Indian Ocean region, examining the influence of solar activity on the Quasi-Biennial Oscillation (QBO) and El Niño-Southern Oscillation (ENSO). The primary objective is to assess the impact of QBO and ENSO on tropical cyclone formation. The equatorial QBO anomaly is analyzed across pressure levels ranging from 10 hPa to 70 hPa, with a particular focus on 30 hPa, using data from the Freie Universität Berlin. To establish a correlation, a normalized occurrence rate of tropical cyclones was derived following the methodologies of Sonnemann and Grygalashvyly (2007) and Ekaterina Vorobeva (2019).

Between 1979 and 2017, a total of 389 tropical cyclones formed in the North Indian Ocean, specifically in the Bay of Bengal and the Arabian Sea. This study primarily examines cyclonic activity during the pre-monsoon (May–August) and post-monsoon (October–December) seasons, utilizing data from the India Meteorological Department (IMD). The results indicate that tropical cyclones predominantly occur during the easterly QBO phase, with 24 out of 39 years exhibiting easterly winds and 15 years experiencing westerly winds.

Statistical analyses, including regression analysis, correlation coefficients, and tests of statistical significance, reveal a strong positive correlation between QBO and tropical cyclone activity. Specifically, a correlation coefficient of 0.7 suggests a significant association between QBO variations and cyclone occurrence in this region.