Ethiopian volcano ash not to affect city’s air

When Ethiopia’s Hayli Gubbi volcano erupted after around 12,000 years on Sunday, it shot a thick plume of ash and sulphur dioxide (SO₂) high into the sky. The plume then moved across continents and entered Indian airspace, triggering concerns in Delhi, which is already reeling under 'severe' and 'very poor' air quality (AQI).

Though the India Meteorological Department (IMD) had predicted that the ash clouds were to leave India by 7.30 pm on Tuesday, concerns existed over how this ash might affect Delhi’s air quality.

How the ash cloud travelled

The ash plume from Hayli Gubbi climbed to altitudes of around 10 to 15 km (or about 33,000-50,000 ft), putting it well into the upper troposphere or even the lower stratosphere. Driven by strong high-altitude winds, the cloud moved rapidly, crossing the Red Sea, passing over Yemen and Oman, and finally entering northwest India. It was first detected over western Rajasthan before sweeping northeast toward Delhi, Haryana and Punjab. According to meteorologists, the speed is roughly 120-130 km/h.

Is Delhi AQI safe from the ash?

Sunil Dahiya, founder of environmental think tank EnviroCatalysts, said: “The volcanic smog at high altitude might not directly impact the air quality, but it will eventually settle down somewhere, which might take days. So the impact on the geographies under the cloud at long distances will be spread over time and space, showing limited impacts in Delhi-NCR.”

The IMD also said because the ash cloud remains very high, it is unlikely to mix down into the air layer that people breathe.

“Though it is unclear whether it will impact air quality, any significant impact is unlikely as it is at higher levels,” the IMD said.

Environmentalist Vimlendu Jha said ash clouds, now visible in Gujarat, Rajasthan and around Delhi, will not immediately affect the AQI.

“The eruption of Ethiopia's volcano is enormous, and if you see it in the last 24 hours, whether we talk about Gujarat, Rajasthan or even in the last 12 hours, we can even see the ashes floating around Delhi,” Jha said. “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 very upper atmosphere," he said.

Risks for aviation & SO₂ factor

Though the health risk to people on the ground appears limited, aviation is a major concern. The Directorate General of Civil Aviation (DGCA) issued an advisory to airlines and airports on Monday to deal with possible disruptions in air operations due to the ash plumes from the volcanic activity in Ethiopia.

As per a news agency, the 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.

Volcanic ash consists of fine, jagged rock and glass particles, which can damage engines. Airlines have been asked to immediately report any suspected ash encounter, including engine performance anomalies or cabin smoke/odour.

There is also a possible concern about sulphur dioxide (SO₂) in the upper atmosphere. Some forecasts say the plume may bring elevated SO₂ levels to high-altitude regions such as the Himalayas or the foothills, though these effects are more speculative and not directly tied to Delhi’s surface AQI.

What IMD expects will happen next

The India Meteorological Department said after passing the Indian region, the clouds will continue moving eastwards, possibly toward China. 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. The authorities are monitoring the plume’s evolution carefully, including its altitude and chemical composition, in case future shifts bring increased risk.