(Phys.org) -- The UK’s appalling summer of weather could have had an unexpected benefit for Olympic athletes and spectators – it could have delivered one of the least polluted Games in history, according to University of Manchester researchers.
Atmospheric scientists are piloting up to eight flights around London, which started in the past month and will continue over the coming weeks, to measure carbon monoxide, ozone, nitrogen dioxide and aerosol levels. They found that the long periods of stormy weather and low pressure have resulted in excellent air quality.
As the wet weather continued into the Games, this could mean the London Olympic Games will be one of the cleanest in recent times.
The University of Manchester Atmospheric Scientists and partners from the Met Office, other UK universities, NERC’s National Centre for Atmospheric Science, and other agencies around the UK, have been monitoring air and ground pollution levels over the past two years as part of Clearflo (Clean Air for London)– a collaborative scientific project to provide long-term measurements of London’s urban atmosphere.
They are monitoring carbon monoxide, nitrogen dioxide and ozone – key markers of pollution and a hazard to health – and harmful aerosol levels in the atmosphere, as well as other chemicals in the atmosphere, and trying to establish what happens to urban pollution and to where it goes.
Early results have shown that lengthy periods of low pressure which have affected the UK for much of the summer have meant that pollution has not settled over the capital but instead has been moved offshore. High pressure areas, typical of warm, sunny weather, trap in pollution and do not allow it to leave.
The airborne component of ClearFlo, led by Dr Grant Allen from The University of Manchester, took to the skies in one of the UK’s dedicated research aircraft which can provide real-time data on pollution levels.
Since the Olympic no-fly zone was put in place, the flights have concentrated on the areas outside the M25, measuring the air quality going in and out of the capital.
Dr Allen said: “Put simply, the reason the air quality is so good is because the weather has been so bad this summer.
“The areas of low pressure have left us with very clean air, unusually clean for summer months over the UK. The pollution that is generated moves away in the evenings and goes in a variety of directions depending on wind direction.”
“A change in the weather, such as that seen in the week leading up to the Opening Ceremony could bring pollution levels back closer to the norm but the processes by which this happens are exactly what we are aiming to study during ClearFlo.
“We have monitored the pollution levels closely during the Games to look for a tell tale shift in the pollution regime. As a result of this combined study, we hope to be able to more accurately predict air quality for London in the future, as well as a better understanding of how London pollution affects those downwind.
“With more accurate predictions, we can hope to mitigate the known health impacts associated with poor air quality. The Olympics provided an excellent case study for us as traffic levels and activity were closely monitored and quantified.
“By sampling the air going into and coming out of London with the aircraft, and using measurements on the ground within the city itself, we can say something about what was added to the air as it passed over London and what this means for those living downwind.”
Funded by the Natural Environment Research Council (NERC), Clearflo also involves a number of scientists on the ground, measuring levels in and around the Olympic Park and other major London venues.
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