UK and London Weather 09/01/2012-15/01/2012

Hello all,

As a student working with Dr Janet Barlow and Dr Omduth Coceal over the course of the Clearflo Project, I thought it would be helpful to provide a brief weekly discussion on the UK-wide and local weather during the course of the IOP’s and how it could potentially be affecting pollution, the Urban Heat Island (UHI), and the boundary layer dynamics in London.

We’ve had a chilly week in London so far, thanks to high pressure dominating across the UK, with the anticyclonic centre originally sitting over Northwestern France and persisting over Europe and towards the North Sea. This blocking high is inhibiting the progress of frontal systems into the UK, and leaving us in well- subsided air, giving us clear conditions and a freely-radiating surface.
In London the weather has grown colder since the start of the IOP. On the 11th of January there was still some cloud cover and maximum temperatures in the realm of 11?C. Then by the 13th there were spots of mist and patchy fog forming as temperatures dropped to freezing at night, followed by dry sunny spells and cooler maximum temperatures closer to 7?C.

By the weekend of the 14th-15th of January high pressure was still well established and influencing London’s weather, and mist and freezing fog has been clearing more slowly in the mornings. Weekend temperatures ranged between -2?C at night and 6?C during the day in the South east.
During such persistent clear periods London’s urban surface will have been warmed more rapidly than rural locations by the absorption of solar radiation, leading to a stronger UHI effect. Additionally, the stationary weather and low winds will have meant that in the past week London’s pollution was likely to be predominantly locally-driven.

It’s also worth noting that during weak-wind and clear-sky conditions, the thermal modification of the boundary layer in response to the UHI is likely to dominate the local meteorology, even over the increased surface roughness’ influence in urban areas. This is also conducive to the formation of a “mixing layer dome” or “dust dome” in which pollution accumulates over the urban landscape in calm meteorological conditions (Arya, 1998).

The 12 UTC Synoptic Analysis on the 15th of January 2012

Aryra, S. P., 1998: Introduction to Micrometeorology
Met Office Weather Forecast
WetterOnline UKMO

A good day at the Kent Show Grounds

Great progress today at the Detling site.  Both Aerodyne containers arrived bright and early and were skillfully dropped into place.  On first inspection all the instrumentation looks like it fared the journey from Boston just fine.  Delivery was held up in London yesterday due to the strong winds.  It was a good thing they did not arrive yesterday because it was simply nasty weather.  Excell electric was also on site and wired up our transformer so we  now have a live instrument container.  Unpacking of the storage container begins. Two additional office containers were also delivered and wired up and the scaffold tower was constructed.  If tomorrow goes anything like today went we should have several instrument on line.

The support from Roger and Jeremy at the show grounds has been fantastic, thank you both.

Bill Brooks from Aerodyne

Aerodyne containers

What a great place to stage.

IOP update – 6th Jan

After a day of lorries, cranes and mud, all the containers, trailers and vans containing the various instruments have arrived at the North Kensington site. So setup for the measurements can now begin. We have a very impressive set of instrumentation (and scientists) present that is sure to produce an equally impressive set of results.

Intensive Operation Period (IOP) first blog post

This is the first blog post at the start of the winter IOP. A large suite of  instruments are currently on their way to the Sion Manning School in North Kensington, London to make detailed measurements of the chemistry and meteorology of London’s atmosphere. The 5 containers, 2 trailers and 1 van should be on site at the in North Kensington tomorrow (6thJan). Then the site can be secured and instrument setup can begin.

Below shows a photo of the York container being collected.

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Dates for IOPs

Winter: 6 Jan – 11 Feb 2012

Summer: 21 Jul – 23 Aug 2012

Call for participation in IOPs

ClearfLo – Clean air for London: Call for participation in winter and summer IOPs

We invite applications for funding for participation in intensive observation periods (IOPs) of the NERC funded ClearfLo project.


ClearfLo is a large NERC-funded project involving 11 UK partners. The ambition is to provide integrated measurements of the meteorology, composition and particulate loading of London’s urban atmosphere, made at street level and at elevated sites, complemented by modelling to improve predictive capability for air quality. Long-term measurements have begun, which will be complemented by more detailed Intensive Observation Periods (IOPs). The aims of the IOPs are (i) to measure the vertical structure of the urban boundary layer, (ii) to determine the oxidation potential of the urban atmosphere, (iii) to measure the properties and composition of particulates in the urban atmosphere. Further information can be found at

Locations and Date:

The IOPs will be held in London, one during winter: 6th January – 11th February 2012; and one during summer during the London Olympics: 21th July – 23th August 2012.

Call for participation:

We have a total budget of £40,000 to fund travel and consumables for scientists not currently involved in ClearfLo to participate in the IOPs. We expect to fund 3-4 proposals.

Proposals should be no longer than one page and should describe (i) the instruments you would bring to the IOPs, (ii) how your measurements would complement the existing suite of measurements, (iii) the name of a ClearfLo PI with whom you are proposing to collaborate, (iv) the expenses required with brief justification. Informal enquiries can be directed to Stephen Belcher (

Applications should be emailed to the Project Manager, Sylvia Bohnenstengel (

Application closing date: Friday 25th March 2011

Applications will be judged by the ClearfLo Project Executive Board and decisions will be circulated in April.

Stephen Belcher (Project Director)

Sylvia Bohnenstengel (Project Manager)