For the past few days, there has been a lot of discussion about volcanic ash in India's capital, Delhi, and many other areas of the country. With air quality already in the severe category, public concern about the potential impacts and timeframe of the ash is natural. However, experts are constantly clarifying that the impact of volcanic ash depends on wind direction, altitude, atmospheric conditions, and intercontinental wind patterns.
In this detailed report, we will understand how such ash reaches India, its impact, and what weather and air quality agencies are saying about it. We will also learn what precautionary measures are necessary for the public.
How does volcanic ash reach India?
Massive volcanic eruptions in distant countries can spread their ash thousands of kilometers through intercontinental airflow. This ash can remain in the upper atmosphere for long periods of time, and it can be carried across continents by strong winds.
It is often observed that after the eruption of active volcanoes in the Pacific and Southeast Asia, their ash moves northwestward for some time. Ash reaching India is usually carried by strong winds (jet streams) in the stratosphere.
However, this ash often reaches India in very small quantities, and in most cases, it remains only in the upper atmosphere, posing no direct threat to people living on the ground.
A mixture of pre-existing pollution and ash in Delhi's air
Delhi is hit by severe air pollution every winter—mainly due to stubble burning, industrial emissions, vehicle pollution, and stable weather conditions. When a light layer of volcanic ash is observed in the upper atmosphere, many assume that its effects will be felt on the ground.
But experts say that:
The direct impact of volcanic ash on ground-level AQI is very limited.
The haze visible in the air is a mixture of local pollution, dust, and moisture.
Usually, ash in the upper atmosphere does not directly affect city air unless it settles, which is rare in India.
What do the Meteorological Department and experts say?
Weather models and air pollution experts suggest that the ash's persistence in the Indian region is temporary and depends primarily on wind direction.
According to them:
1. The ash will be carried away if the wind direction changes.
When the jet stream changes, the ash moves to a new area within a few days.
2. The ash is not reaching the ground.
Data from monitoring stations in India indicate that the ash layer is at an upper level and has very little direct impact on breathable air.
3. The effects of ash are temporary
According to experts, in most cases, volcanic ash lasts for two to five days before conditions return to normal.
Did ash impact visibility in Delhi?
Low visibility in Delhi during winter is not uncommon. In November and December, humidity, particulate matter (PM2.5 and PM10), vehicle exhaust, and industrial pollution combine to form smog. While upper-level ash can sometimes affect sunlight, the observed drop in visibility is mostly due to local pollution.
Can volcanic ash impact health?
If ash reaches the ground, its extremely fine particles can have health effects. However, the density of such particles that reach India is extremely low, so the impact is almost negligible.
However, for those with asthma, allergies, or lung problems, it's always best to exercise caution, as overall air quality remains poor.
Some precautionary measures:
Wear an N95 mask when outdoors
Avoid going out early in the morning and at night
Use an air purifier
Stay hydrated
Keep windows closed when the AQI is poor
Will the ash have any impact on India's weather?
Ash in the upper air blocks some sunlight, potentially causing a slight change in temperature for a short time. However, this effect is usually very weak and unnoticeable.
According to meteorologists:
Volcanic ash does not significantly impact India's normal weather patterns.
Its impact on rainfall, wind speed, and temperature is minimal.
When will the ash leave India?
This is the question that people are most concerned about. Experts say that the ash plume:
will move as the wind direction changes,
it typically moves from its location within two to five days,
it is highly unlikely to last long in India.
That is, it is safe to say that the ash's impact is temporary, and under normal conditions, the atmosphere begins to clear within a short time.
What can be expected for Delhi?
The main cause of pollution in Delhi is not ash, but local sources and weather conditions. Therefore, improvements in air quality will depend on wind speed, temperature, and humidity.
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