Pollution ‘had some effect’ on solar eclipse visibility

King’s College London air quality analyst says high particulate levels in UK contributed to poor visibility for the solar eclipse

High levels of air pollution this week are likely to have contributed to poor visibility during the solar eclipse in parts of the UK this morning (March 20), according to a King’s College air quality analyst.

In several parts of the UK, including London, many were left disappointed at not being able to clearly view the solar eclipse at due to poor visibility and weather conditions.

It was the first such eclipse visible in the UK in more than a decade, while the next is not due to take place until September 2090.

Meanwhile, Defra and local authorities have issued alerts and health warnings this week in response to high levels of particulate matter pollution being monitored across the UK and Europe. There were also reports that the situation affected visibility of the Eiffel Tower in Paris (see airqualitynews.com story).

And, speaking to airqualitynews.com today (March 20), King’s College air quality analyst Andrew Grieve said that the particulate pollution “will have had an effect” on visibility in parts of the UK this morning.

But he explained that the sun in the afternoon would improve visibility as it burns off the clouds: “It has been quite cloudy in the mornings, which means the dew point [the point where condensation occurs] of the air drops.”

However, Mr Grieve said it was difficult to say quite how big an impact the particulates will have had on visibility, as he said this was affected by “a combination of atmospheric causes and the air pollution”.

He said: “We will have a look at that in the next couple of weeks to try to determine just how much nitrates and sulphates were in the air.”

Mr Grieves also explained that episodes of high particulate pollution are more common in the spring time and April, but less common in the summer due to the warm temperature. Episodes of high levels of ozone pollution are therefore more common in the summertime, while high levels of nitrogen dioxide were a bigger problem in colder winter weather in the UK.

Commenting on the pollution episode this week, he said that Tuesday was probably the worst day: “It looks like it was coming across from the likes of Russia, Romania, Poland, the Netherlands and hitting us.”

Paris

In previous episodes of high air pollution, Paris has sought to limit cars on the roads by only allowing even-numbered license plates to drive on one day, and odd-numbered plates on another day, but the KCL analyst said such a policy was unlikely to have much direct effect on pollution levels.

He said: “It has a tiny effect but not much of an effect if it is just for one or two days. The other school of thought is that by asking people to at least think about driving into the city, it at least raises awareness of the issue. So it depends whether you come at it from a pure science point of view or not.”