Groups and Divisions

 

Subject Groups

Past Meetings

5th Environmental Physics Group Members' Meeting

Wednesday 14 May 2008

Lovelace Room, Institute of Physics, 76 Portland Place, London W1B 1NT

The fifth EPG Members' Meeting promises to provide an excellent opportunity for the community to get together and discuss the diversity and depth of environmental physics. The Members' Meeting will include a variety of talks from EPG members, and the EPG essay winners will also be announced. A keynote lecture will be given by Prof Richard Wakeford.

This year we have especially encouraged early career environmental physicists (students and all those who have graduated within the last 10 years) to present research, and likewise we encourage them to attend the meeting. Travel grants are available. The meeting will also incorporate the Group's AGM and will be followed by an evening lecture. Following the successful talk to the IOP in Dublin last year on the 50th anniversary of the Windscale nuclear reactor incident, Professor Wakeford, will present his talk as the evening lecture. Further details of Professor Wakeford's talk are advertised separately on the website.

Confirmed speakers for the Members' Meeting include:

  • The Mace Head site and other condensation stories, Prof Gerry Jennings
  • Trapping aerosols with light, Dr David McGloin, University of Dundee
  • Observing and modelling insect migration in the atmospheric boundary layer, Dr Curtis Wood, Reading University
  • Desert Challenges: Towards better prediction of gaseous fluxes from Kalahari soils, Dr Stephen R Hoon (speaker) and Dr A D Thomas, Manchester Metropolitan University
  • Why renewable energy? How the reasons for wanting renewables are changing, Dr Donald T Swift-Hook, World Renewable Energy Network.

Please click here for the programme.

The Windscale nuclear reactor accident - 50 years of investigations

Prof Richard Wakeford, University of Manchester

Wednesday 14 May

Franklin Room, Institute of Physics, 76 Portland Place, London W1B 1NT

Although it happened half a century ago, the nuclear reactor fire during October 1957 at Windscale Works, Sellafield, England, remains the largest accidental release of radioactive material into the environment that has occurred in the West. Extensive investigations into the causes and consequences of the Windscale accident have been carried out over the past fifty years, including a recent re-evaluation of the quantities of radionuclides released to atmosphere and their subsequent travels over northern Europe. The presentation will provide a background to the accident, what happened during the fire, the environmental monitoring that took place, and our current understanding of the aerial emissions and the movement of the plume, including the recent work on this subject.

A further introduction to the Windscale disaster was presented in our November Newsletter.

This talk will follow the Environmental Physics Group AGM (see separate notice on the website), to which members are warmly invited.

Climate Change 2007: the physical science basis

Evening lecture by Prof Jonathan Gregory
Thursday 28 February 2008, 6:30pm, Dublin Institute of Technology (DIT), Kevin Street site.

Condensation processes

Dublin, 29 February 2008

Please click here for programme and registration information.

Measurement Methods in Environmental Electrostatics

Wednesday 5 July 2006, Institute of Physics, London

History of Air Pollution meeting, held at Dirac House in Bristol on 30 November 2005.

Presentations can be downloaded in PDF format.


Report on a half-day seminar held at the Institute of Physics on 4 November 2002 entitled Physics of the Built Environment.

The purpose of the event was to provide an opportunity for building physicists to meet up and, more generally, to raise awareness of the application of physics in construction. The meeting was well attended by approximately 60 people, one third of whom were members of the Environmental Physics Group. Six specialists presented on the following topics.

Adrian James from Adrian James Acoustics UK spoke about the Physics of Sound Transmission in and through Buildings. He detailed the important variables of amplitude, loudness, pressure and Sound Pressure Level, frequency and pitch and went on to describe the difficulties in computer modelling and physical modelling of room acoustics, touching on diffusion with respect to surfaces. He commented on the current level of auralisation techniques and referenced back to the Roman amphitheatres to look at previous knowledge of acoustics.

David Infield from CREST (Centre for Renewable Energy Systems Technology), Department of Electronic and Electrical Engineering, Loughborough University presented work on localised energy sources such as building integrated photovoltaics (BIPV), building integrated wind power, micro-and mini- CHP (Combined Heat and Power) and energy storage. He described some key difficulties with BIPV.

Mike Holmes from Arup Research and Development discussed the modelling of the internal climatic conditions within buildings. With a particular focus on the Eden Project, Mike explained the challenges of designing a ventilation system for the Humid Tropics and Warm Temperature biomes where strict limits in the acceptable fluctuations of air temperature and humidity were required for plant growth. Mike showed that by applying mathematical models representing the fundamentals of heat and moisture transfer within computer software, it is possible to test a proposed design before the building is constructed.

Jose Gallego (Glass coatings department, Pilkington) described the physics of the passage of solar radiation through glass. Glazing in buildings is a particularly crucial issue because it is popular with architects for aesthetic reasons and popular with building users who value a connection with the outside world. However, the thermal resistance of basic clear float glass is poor and the transmissivity of solar radiation is high. The former property can lead to excessive heat loss in winter and the latter can help generate overheating in summer. The recently revised building regulations have placed greater constraints on the use of glass in buildings by requiring a higher than previous thermal performance of the building envelope. Fortunately a number of glass technologies exist to allow glass to be used and thermal performance to be maintained. These include tints and coatings. Dr Gallego demonstrated that it was possible to obtain a wide range of reflection, absorption and transmission properties by using a combination of coatings and tints.

Suresh Kumar (Fire Research, BRE) described recent advances in the field of fire safety modelling. He highlighted the needs for validation of computational fluid dynamics (CFD) simulations and the importance of the mathematical representation of the fire within such analysis. Dr Kumar showed that there were questions about the validity of using a prescribed fire growth curve (the relationship between heat source from the fire and time) in all cases. Instead, he advocated the implementation of a combustion model within the CFD simulation. The advantage of this approach is that it enables the heat flux to vary with the amount of available oxygen, a feature not included explicitly in the alternative approach. This issue can be important in some cases, particularly in a small enclosure where supply of oxygen may be limited. Dr Kumar also explained the importance of modelling heat transfer by radiation from the fire and hot smoke to other parts of the space, and how this could lead to "flashover".

Julian Hunt (University College, London) discussed the physics of the external environment of urban areas. Professor Hunt showed how fluid dynamics can help illuminate how winds change as they pass through the large groups of buildings that make up urban areas, and how local terrain can also give rise to slope winds at night. Julian showed how mathematical models can give useful quantitative estimates of urban meteorology and pollutant distribution and dispersion.

Peter Hedges (EPSRC) presented some of the challenges facing the built environment and the important role that must be played by engineers and physical scientists in addressing these. Dr Hedges highlighted the 60% reduction in CO2 emissions by 2050 that had been recommended by the Royal Commission on Environmental Pollution and the need for sustainable development. He explained that the government spending reviews had been generous towards the sciences but that there was an expectation on the universities to use the funding wisely to produce meaningful, applicable outputs. He emphasised the need for research in the areas of climate change, energy efficiency and low carbon energy sources and transport research (including pollution modelling and clean vehicle technology). He called upon physicists to take a pro-active role in driving forward multi-disciplinary research to answer these challenges.

Report on a lecture given at the Institute of Physics on 9 January 2002 by Professor James Milford entitled Environmental physics in totality: observations during an African eclipse.

As part of a larger project to study the effect of a total solar eclipse on animal behaviour, James Milford of the Physics Department of the University of Zimbabwe, set up three automatic weather stations within the Mana Pools World Heritage Site close to the Zambesi River, which is the northern border of Zimbabwe with Zambia. The three automatic weather stations, which were up to two kilometres apart, were surrounded by different densities of vegetation typical of the area. At all three sites air and soil temperatures, air humidity and incoming radiation were measured every few seconds before being averaged over three or five minutes. In addition, at one of the sites measurements were made of wind speed and direction, soil moisture and soil heat flux. Conditions for studying the effect of a solar eclipse on meteorological variables were ideal with cloud-less conditions on the day of the eclipse and on the previous and subsequent days, when measurements were also made. The automatic weather station measurements showed very similar diurnal variations of air temperature at the three sites and nearly identical maximum solar radiation for the three days. During the three day period that there was only a light wind. Each day the wind started blowing about 7:30 a.m. reaching a maximum of 1 m s-1 near mid-day and then returning to zero by about 4:30 p.m.

The total eclipse on 21 June 2001 lasted 3 minutes 20 seconds centred on 1506 local solar time. On that day the incoming solar radiation was reduced over a three hour period with zero solar radiation being measured at the time of the total eclipse, i.e. it became completely dark, compared to 440 W m-2 at the same time on the previous and subsequent days. This reduction in radiation caused a fall of 4EC in air temperature and at the same time the wind speed became negligible - about 2 hours earlier than on the other days. After the passing of the eclipse the air temperature and humidity increased to reach higher values than on the other days. The reduction in wind speed during the eclipse suggested a decrease in convective exchange during this period. If this resulted in a shallower convective layer during the eclipse there would be a greater build-up of heat and water vapour within the convective layer, when the sun's radiation again reached the earth's surface, and explain the observed higher values of temperature and humidity. The observations of air and soil temperatures over the three days were also compared. At the end of each night it was found unexpectedly that the soil temperature at 20 mm was consistently warmer than the air temperature. Estimation of the temperature at the soil surface showed that it was 2EC warmer than the air temperature - no explanation for this phenomena could be put forward.

Photos and a professional video increased the pleasure of this presentation of a rare event seen and recorded under ideal conditions.

John Stewart

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Artwork | Image by Fred Swist