This study explores how a major weather pattern called the Madden-Julian Oscillation (MJO) affects the ocean environment in the northern Bay of Bengal from 2000 to 2024. The MJO is a repeating pattern of storms and calm periods that moves across the tropics every 30 to 60 days. It influences weather, ocean conditions, and marine life. By analyzing satellite data on ocean color (chlorophyll, which shows how much tiny plant-like organisms grow), rainfall, wind speed, and MJO strength, the research shows that ocean productivity changes depending on MJO activity. During active MJO phases—when the atmosphere is more dynamic—strong winds and heavy rains help mix nutrients into the ocean, especially near coasts and rivers. This leads to more chlorophyll and supports marine life. However, in calm periods (inactive MJO), fewer nutrients are available, so ocean productivity drops. The study also found that certain MJO phases and seasons (especially summer and spring) are more strongly linked to these changes. By creating maps of ocean and weather data, the study shows how MJO patterns shape marine ecosystems. These findings help us understand how climate patterns affect the ocean and can improve forecasting for sustainable marine resource management.