Discuss the mechanism through which El Niño affects the Indian monsoon and examine its implications for heatwave preparedness in peninsular states like Andhra Pradesh.

Q. Discuss the mechanism through which El Niño affects the Indian monsoon and examine its implications for heatwave preparedness in peninsular states like Andhra Pradesh. (15 marks, 250-350 words)

El Niño, the warm phase of the El Niño–Southern Oscillation (ENSO), is an anomalous warming of central and eastern equatorial Pacific sea surface temperatures (SSTs); an anomaly exceeding 2°C marks a "very strong" event (1972, 1982, 2015, 2023). Its teleconnection with the Indian summer monsoon makes it simultaneously a rainfall risk and a heat-stress risk for peninsular India.

Mechanism of monsoon disruption - Walker circulation shift: Pacific warming displaces the ascending limb eastward, placing the subsiding limb over the Indian subcontinent, suppressing convection [1]. - Weakened land–sea thermal gradient: reduced pressure contrast slows cross-equatorial moisture influx, delaying onset and causing mid-season breaks [1]. - Empirical record: unambiguous ENSO warm events have been overwhelmingly associated with all-India monsoon droughts, though the correlation weakened post-1976 and can be offset by the Indian Ocean Dipole [1]. - Compounding effect: rainfall deficit and clear skies raise sensible heating, extending pre-monsoon heatwaves into June–July.

Implications for heatwave preparedness in Andhra Pradesh - Mortality burden: the 2015 El Niño heatwave killed over 2,300 nationally, with 1,369 in A.P. alone — the country's worst state toll [4]. - Reactive institution-building: APSDMA was created only after 2015, illustrating that Indian disaster institutions typically follow mass-casualty events [4]. - Capacity built since: real-time automatic weather station data, a Heat Wave Atlas and mandal-level advisories now underpin early warning, and heat deaths have fallen sharply [3]. - Framework anchor: NDMA's heatwave guidelines and Heat Action Plans standardise thresholds (40°C plains; 45°C declaration) and vulnerability targeting for outdoor labour and the urban poor [2]. - Live test: May 2026 saw nine consecutive days above 44°C, peaking at 48.3°C, with a below-normal monsoon forecast [4].

El Niño thus converts a distant oceanic anomaly into a domestic public-health emergency. Sustaining A.P.'s gains requires shifting from event-triggered response to anticipatory governance — seasonal-forecast-linked Heat Action Plans, cool roofs, work-hour regulation and shaded public infrastructure — aligning disaster preparedness with the Disaster Management Act's mitigation mandate and SDG-13 on climate action.

(~330 words)

Sources: 1. El Niño, Southern Oscillation, equatorial eastern Pacific SSTs and summer monsoon rainfall in India — MAUSAM, IMD — ENSO–monsoon teleconnection, warm events associated with droughts, weakening post-1976 correlation 2. NDMA, Heat Wave — Natural Hazards & Guidelines — heatwave thresholds (40°C plains, 45°C declaration), Heat Action Plan framework and vulnerable-group targeting 3. Andhra Pradesh State Disaster Management Authority (APSDMA), official portal — automatic weather station network, Heat Wave Atlas, mandal-level heat advisories 4. A.P. and the next El Niño challenge — The Hindu (news report, 13 July 2026) — 2015 death toll (2,300 national / 1,369 A.P.), APSDMA's post-2015 formation, May 2026 heatwave and below-normal monsoon forecast