What is the Madden-Julian Oscillation (MJO)? Explain its phases and global movement. How did MJO’s strong amplitude recently influenced early rainfall over India?
Kartavya Desk Staff
Topic: Salient features of world’s physical geography
Topic: Salient features of world’s physical geography
Q2. What is the Madden-Julian Oscillation (MJO)? Explain its phases and global movement. How did MJO’s strong amplitude recently influenced early rainfall over India? (15 M)
Difficulty Level: Medium
Reference: IE
Why the question: Early monsoon onset linked to an active MJO phase; highlights the growing importance of intra-seasonal climatic oscillations in influencing India’s monsoon system. Key Demand of the question: The answer must define MJO clearly, explain how its phases and movement influence weather globally, and analyse how the recent high-amplitude MJO led to early monsoonal rainfall in India. Structure of the Answer: Introduction Mention MJO as a key intra-seasonal phenomenon influencing tropical convection and monsoon dynamics, with specific reference to May 2025. Body What is MJO – Explain it as a slow-moving equatorial disturbance of cloud, wind, and pressure with significant weather impacts. Phases and global movement – Describe the 8-phase model and eastward movement across the tropics with periodic global impact. Impact on India (2025 case) – Show how Phase 4 with strong amplitude triggered early monsoon onset in Kerala and Mumbai through enhanced convection and cyclogenesis. Conclusion Emphasise the need to integrate MJO indicators into India’s climate risk preparedness and forecasting systems.
Why the question: Early monsoon onset linked to an active MJO phase; highlights the growing importance of intra-seasonal climatic oscillations in influencing India’s monsoon system.
Key Demand of the question: The answer must define MJO clearly, explain how its phases and movement influence weather globally, and analyse how the recent high-amplitude MJO led to early monsoonal rainfall in India.
Structure of the Answer:
Introduction Mention MJO as a key intra-seasonal phenomenon influencing tropical convection and monsoon dynamics, with specific reference to May 2025.
• What is MJO – Explain it as a slow-moving equatorial disturbance of cloud, wind, and pressure with significant weather impacts.
• Phases and global movement – Describe the 8-phase model and eastward movement across the tropics with periodic global impact.
• Impact on India (2025 case) – Show how Phase 4 with strong amplitude triggered early monsoon onset in Kerala and Mumbai through enhanced convection and cyclogenesis.
Conclusion Emphasise the need to integrate MJO indicators into India’s climate risk preparedness and forecasting systems.