How a volcano 4,000 km away raised pollution concerns in Delhi and disrupted flights

Several Indian airlines, including Air India and Akasa Air, cancelled multiple flights on Tuesday (November 25) after a massive cloud of volcanic ash from an eruption in Ethiopia drifted across northwestern India, disrupting operations. The Hayli Gubbi volcano in Ethiopia’s Afar region erupted on Sunday for the first time in recorded history, spewing ash up to 14 km into the atmosphere.

The volcanic ash first reached Gujarat before drifting north and east across the plains, prompting airlines to adjust flight paths and cancel departures as a safety precaution. Officials said the ash clouds were concentrated at high altitudes, posing risks to aircraft engines.

Also read | DGCA warns airlines as volcanic ash from Ethiopia drifts towards India

The India Meteorological Department (IMD) said the ash is now drifting towards China and is expected to clear from Indian skies by 7:30 pm on Tuesday.

Which parts of India were affected, and could the volcanic ash worsen Delhi’s already poor air quality?

High-level winds carried the ash cloud from Ethiopia across the Red Sea to Yemen and Oman, before sweeping over the Arabian Sea and into western and northern India, said the India Meteorological Department (IMD) in a statement.

Driven by strong winds of 100–120 km/h, the ash plume travelled thousands of kilometres and entered Indian airspace late Monday night, passing over Gujarat, Rajasthan, Maharashtra, Delhi-NCR and Punjab. The haze reduced visibility in several regions and coincided with already hazardous air quality in Delhi. As it moved eastward across the skies, the ash cloud reduced visibility and disrupted air traffic in several regions.

The IMD said the plume was expected to continue its eastward journey toward China and clear Indian skies by 7:30 pm. “It will temporarily affect satellite functions and flight operations, but it is unlikely to impact weather conditions or air quality. It reached northern India last night and now appears to be heading towards China,” IMD Director General Mrutyunjay Mohapatra told the BBC.

The IMD’s key point is that because the ash cloud is positioned at a very high altitude, it is unlikely to descend and mix with the lower layers of air that people breathe. It believes any direct impact on Delhi’s AQI will be short-lived and largely superficial, limited to haze or slight temperature changes, rather than a spike in harmful particulate pollution.

A section of experts has also downplayed concerns, noting that the ash plume is travelling at a very high altitude, roughly 25,000 to 45,000 feet, and is unlikely to have a major impact on pollution at ground level. What Delhi residents may observe instead are unusual sunrise hues caused by the ash scattering sunlight in distinct patterns.

Another weather expert said the ash plume mostly consists of sulphur di-oxide with low to moderate concentrations of volcanic ash. “It will not impact AQI (air quality index) levels, but it will impact SO2 levels in the hills of Nepal, the Himalayas and the adjoining Terai belt of Uttar Pradesh, as some of the material will bump into the hills and later move into China,” the expert wrote on X.

Environmentalist Vimlendu Jha said that the ash clouds, now visible in Gujarat, Rajasthan, and around Delhi, will not immediately affect the AQI. “The overall impact of the eruption will be in the form of ash clouds and will not immediately affect the AQI in Delhi. The clouds are made of sulphur dioxide (SO2) and glass particles. Though it will not immediately affect the AQI, we need to monitor it, as the clouds are in the upper atmosphere,” he told news agency ANI.

However, some experts caution that any large ash mass drifting over the region warrants close monitoring. “The volcanic ash consists of dust, silica, rocky material, and other minerals and can be hazardous to health. Volcanic ash while passing over the air shed over Delhi may lead to a sudden spike in pollution levels, worsening the air quality further,” Sunil Dahiya, founder and lead analyst of think tank EnviroCatalysts, was quoted as saying by The Times of India.

How has the volcanic eruption in Ethiopia disrupted flight operations in India?

Air India has cancelled at least 11 flights since Monday and is carrying out precautionary checks on those planes that had flown over locations that had ash plumes.

Air India said it has cancelled four flights on Tuesday -- AI 2822 (Chennai-Mumbai), AI 2466 (Hyderabad-Delhi), AI 2444/2445 (Mumbai-Hyderabad-Mumbai) and AI 2471/2472 (Mumbai-Kolkata-Mumbai).

On Monday, it had cancelled seven international flights, including AI 106 (Newark-Delhi), AI 102 (New York (JFK)-Delhi) and AI 2204 (Dubai-Hyderabad) and AI 2290 (Doha-Mumbai). Similarly, Akasa Air said it cancelled flights to Middle East destinations such as Jeddah, Kuwait and Abu Dhabi that were planned for the two days.

Giving the flight details in a post on X on Tuesday, Air India said it is carrying out precautionary checks on those aircraft which had flown over certain geographical locations after the Hayli Gubbi volcanic eruption.

Also read | Ethiopian volcanic ash to move away from India: IMD

“Our ground teams across the network are keeping passengers updated on their flight status and are providing immediate assistance, including hotel accommodation. We are making every effort to arrange alternative travel at the earliest,” the airline said.

In a detailed advisory on Monday, the Directorate General of Civil Aviation (DGCA) asked airlines to strictly avoid published volcanic ash affected areas and flight levels, adjust flight planning, routing, and fuel considerations based on the latest advisories. Also, airlines have been asked to immediately report any suspected ash encounter, including engine performance anomalies or cabin smoke/odour.

What exactly happened at the Hayli Gubbi volcano, and why is this eruption historic?

The Hayli Gubbi volcano, located in Ethiopia’s Afar region, burst into activity on Sunday, sending massive ash plumes soaring nearly 14 km into the atmosphere and blanketing several nearby villages.

The volcano itself rises about 500 metres and sits within the geologically active Rift Valley, where two tectonic plates are slowly pulling apart.

Unverified videos circulating online showed a towering column of pale smoke shooting upward. Residents in the quake-prone Afar region said they felt the ground shake and heard a loud blast. One witness described it to AP as feeling like “a bomb had suddenly gone off, releasing smoke and ash.”

According to the Smithsonian Institution’s Global Volcanism Program, Hayli Gubbi has not recorded any eruptions during the Holocene, the last roughly 12,000 years since the previous Ice Age.