Will the Ethiopian volcano ash cloud actually worsen Delhi’s AQI?

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. That plume has since moved across continents and entered Indian airspace, triggering concerns in Delhi, which is already reeling under 'severe' and 'very poor' air quality (AQI). But will this volcano ash worsen AQI in Delhi? According to the India Meteorological Department (IMD), the impact on Delhi’s ground-level air pollution is likely to be very limited.

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?

The IMD’s central argument rests on altitude because the ash cloud remains very high, it is unlikely to mix down into the air layer that people breathe.

IMD has said that although it is unclear whether it will impact air quality, any significant impact is unlikely as it is at higher levels.

Environmentalist Vimlendu Jha said that the 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 told news agency ANI. “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 added.

He explained that the impact might be seen in high-altitude regions like the Himalayas, the Tarai belt, and parts of China, where SO₂ levels might elevate.

Current AQI and local pollution still dominant

Delhi’s AQI is already extremely poor, driven by local pollution sources like vehicular emissions, construction dust, biomass burning, and weather-related inversions. On the day after the plume’s arrival, Delhi’s average AQI was around 363–364, according to CPCB (Central Pollution Control Board) and IMD-cited reports. More than half of monitoring stations showed AQI over 400, which is 'severe', with some hitting 450+ placing it in the 'hazardous' category.

Risks for aviation and the SO₂ factor

Although 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 news agency PTI, 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 the IMD expects to happen next

The IMD expects the ash cloud to clear Indian skies by around 7:30 pm, after which it 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.