Producing quantitative estimates of radiative forcing

By Will Davies

Last year the Paris climate conference agreed to an action plan to limit global warming to below 2 degC – preferably 1.5 degC. Various initiatives are measuring performance against this target – such as the global warming index which provides an index of human-induced global warming relative to pre-industrial times, and the Copernicus Atmosphere Monitoring Service (CAMS) which will deliver operational services including near-real-time analyses and forecasts of atmospheric composition, and estimates of instantaneous radiative forcing (RF).

The difference in the amount of radiation received from the sun and the amount that is radiated back into space is referred to as the Earth’s energy budget. RF measures the imbalance in this budget when the climate system is perturbed by components such as greenhouse gases, aerosols and clouds.

Here in Reading I am part of a CAMS team producing quantitative estimates of RF with respect to pre-industrial times (PI) using PI concentrations provided in the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) from year 1750. The production chain being developed will use a CAMS global reanalysis dataset which will include data assimilated from recent satellite launches such as Sentinel-3 in order to produce improved RF estimates. CAMS consolidates previous research such as MACC and so the CAMS production chain has been prototyped using MACC reanalysis data.

The CAMS 74 production chain uses a radiative transfer (RT) code that is based on the standalone version of the Rapid Radiative Transfer Model for General circulation models (RRTMG) as used in the European Centre for Medium-Range Weather Forecasts (ECMWF)’s Integrated Forecast System (IFS). The development of this RT code will include stratospheric temperature adjustment using the seasonally-evolving fixed dynamical heating approximation.

Early versions of the code have been run on MACC reanalysis data – see Figures 1,2 and 3.

2016 10 13 Will Davies - Fig1

Figure 1. The 2007 annually-averaged RF for the aerosol-radiation interaction (ari) short wave (SW) RF, the aerosol-cloud interaction (aci) SW RF, the all sky methane (CH4) long wave (LW) RF and the all sky carbon dioxide (CO2) SW+LW RF

2016 10 13 Will Davies - Fig2.pngFigure 2. The mean global distribution of the methane RF at the top of atmosphere (TOA) for a clear sky on 21 June 2009, showing the effect that meteorological conditions have on the methane RF.2016 10 13 Will Davies - Fig3Figure 3. The CO2 TOA LW clear sky yearly instantaneous RF from 2003 to 2009 which shows the steady increase in RF and hence global warming caused by CO2 emissions.

Many scientists see the Paris 2015 target as ambitious. The radiative forcing products provided by the CAMS monitoring service will clarify this and will help to highlight the scale of the challenge that we face.



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El Niño in West and Central Africa

By Chimene Daleu


What is El Niño, how often does it occur, and why is everyone so concerned this year?
El Niño is the warming phase of the El Niño Southern Oscillation (ENSO). During an El Niño event, the central to eastern tropical Pacific warms by 0.5-2 degC or more for anything between a few months to two years. El Niño occurs, on average, every three to seven years. It impacts weather systems around the globe so that some places receive more rainfall while others receive none at all, often in a reversal of their usual weather pattern.

There were super El Niño events in 1972-73, 1982-83 and in 1997-98, the latter bringing record global temperatures alongside droughts, floods and forest fires. The current El Niño has already affected millions of people and comes on top of already volatile and erratic weather patterns linked to climate change. Globally, 2014 and 2015 were the hottest years on record, with the Pacific Ocean already warming up to an unprecedented degree.

El Niño in West and Central Africa
Experts have confirmed that unusual high surface temperatures at the end of 2015 and in January 2016, above the annual increase, are an indication that El Niño could have possibly impacted West and Central Africa (particularly in Chad, Cameroon and the Democratic Republic of the Congo) from September 2015 to March 2016. However, since January 2016, a decrease in ENSO intensity was noted. Most model outputs and expert assessments have suggested a persistence of this decreasing trend leading to ENSO neutral conditions starting from May 2016.

2016 10 06 Chimene Daleu Fig 2.png

Figure 1. Source:

2016 10 06 Chimene Daleu Fig 3

Figure 2. Source:

Predictions – June to September 2016 for West and Central Africa
Figures 1 and 2 show the seasonal temperature and precipitation that were forecasted for July to September 2016, while Figure 3 shows significant weather and climate events expected from June to September 2016.

  • Below average precipitation was very likely from July to September 2016 over the west part of Guinea, Sierra Leone, Liberia, southern Côte d’Ivoire, Ghana, Togo Benin and Nigeria, southeastern CAR, Sudan, northern DRC, Uganda and most of South Sudan and Ethiopia.
  • Near to below average precipitation was very likely over the most of the coastal part of Mauritania, Senegal, Gambian and Guinea Bissau, the Gulf of Guinea from Sierra Leone to Nigeria during June to August period.
  • Over the northern Guinea, central Sahel region, near to above average precipitation was very likely from June to September 2016.
  • Near to above average temperature was very likely over most part of northern Africa, the Sahel region and southern Africa from June to September, 2016.
  • Above average temperature was very likely during June to September 2016 over Morocco, Algeria, Tunisia, northern Libya, northern and eastern Egypt, northernmost Mauritania and Mali.

2016 10 06 Chimene Daleu Fig 4

Figure 3. Source:


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Helping National Grid manage the sudden growth in solar power

By Daniel Drew

In Britain it had been a year without summer. Wet spring had merged imperceptibly into bleak autumn. For months the sky had remained a depthless grey. Sometimes it rained, but mostly it was just dull, a land without shadows. It was like living inside Tupperware”.

Bill Bryson, The Lost Continent: Travels in small town America

Given the reputation of the Great British weather, it is perhaps surprising that the UK now has more solar panels than France, Spain and Australia. Some of these installations generate hot water (solar thermal) but the vast majority harness the photoelectric effect to generate electricity, known as solar photovoltaic cells, or solar PV (potentially confusing initials for a meteorologist). Since January 2014 the installed capacity of solar PV has increased dramatically from 2.8 GW to 10.7 GW (as of July 2016), nearly all of which benefit from feed-in tariffs which guarantee a set income for each kWh of solar generation.

While the increased proportion of renewable generation is beneficial to reducing the carbon intensity of UK electricity, it does present a challenge to National Grid, the system operator responsible for ensuring supply equals demand throughout the day. Solar PV generation is highly variable over a range of temporal scales. Clearly there is a well understood seasonal and diurnal pattern, but also higher frequency variability due to clouds. National Grid is however used to dealing with variable generation, over the last 15 years the capacity of wind power in the UK has steadily increased to 14.5 GW (as of January 2016). During this time, National Grid has been working on research projects (including several with the University of Reading) to develop a detailed understanding of the variability and predictability of UK wind power.

Solar generation presents a new challenge. Whereas wind capacity is located in a relatively small number of very large wind farms, solar PV capacity is distributed across a large number of small installations- typically on the rooftops of buildings. The installations are generally very small, therefore the owners are under no obligation to provide National Grid with electricity generation data or even inform them of the existence of the panels. Solar generation is therefore ‘seen’ by National Grid simply as a reduction in the electricity demand. Proportionally this reduction can be quite large, particularly on a clear weekend day in summer when the electricity demand is typically only 25 to 30 GW.

To maintain the previously accurate predictions of electricity demand, an understanding of the variability and predictability of solar generation is required. Our project uses state-of-the-art meteorological datasets to address questions such as; how changeable is UK solar power? How extreme can solar power swings get? Are they correlated with swings in wind power? How well are extreme events forecast?

Find out more about our project at

2016 09 22 Daniel Drew - Fig 1 demand_schematic

Illustration of the reduction in GB electricity demand as observed by National Grid due to solar PV generation on a typical summer weekday.

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La Nina outlook

By Emma Suckling

In late 2015 and early 2016 a strong El Nino event, characterised by warmer than normal temperatures in the Pacific Ocean, developed and led to a variety of global effects. These included drier than normal weather in Indonesia and the Philippines, wetter than normal conditions over parts of South America and warmer, wetter conditions over much of the south in the United States.

Since El Nino reached its peak last November, forecasters have turned attention to the possible development of a La Nina event in late 2016 and early 2017. La Nina events, characterised by prolonged cooler than average temperatures in the Pacific Ocean, often (but not always) develop following a strong El Nino event. The timing and strength of such an event can have a variety of implications for climate patterns worldwide (see Figure 1). Organisations such as the Department for International Development (DFID) are therefore interested in monitoring the development of conditions in the atmosphere and oceans associated with a La Nina, as well as understanding the potential impacts of a La Nina event across certain vulnerable regions. These potential impacts are assessed by combining information from analysis of historical impacts during previous La Ninas, climate model forecasts that predict 1-3 months ahead and by monitoring current climate conditions across the globe.

 2016 09 22 Emma Suckling - figure1

Figure 1: Potential global impacts of a La Nina event. Source:

Following the 2015/16 El Nino, conditions in the Pacific returned to neutral (neither an El Nino or a La Nina) in the spring of 2016. Sea surface temperatures in the Central Pacific have been significantly below average over the last three months, consistent with the formation of weak La Nina conditions. However temperatures across the whole Pacific region have not cooled as much or as quickly as predicted earlier in the year, suggesting that if a La Nina does develop it will likely be a weak event.

Forecasts made earlier in the summer suggested La Nina conditions were slightly favoured (with around a 55-60% chance) to develop during late 2016. More recent forecasts have suggested a diminished likelihood of a La Nina event developing, with Pacific Ocean temperatures predicted to be near-normal for the remainder of 2016 (see Figure 2). Some models still indicate a possible weak La Nina event this winter, although many other phenomena associated with La Nina are either absent or only weakly present in the models, causing forecasters to downgrade their predictions.

2016 09 22 Emma Suckling - figure2

Figure 2: CPC/IRI Official Probabilistic El Nino Southern Oscillation (ENSO) forecast from September 2016. Probabilities for El Nino, neutral, or La Nina conditions for each three-month period during late 2016 to early 2017. Neutral ENSO conditions are currently favoured over the coming months. Source:

The potential absence of a La Nina event over the coming months has consequences beyond the just Pacific region. This includes implications for how the tropical cyclone and Atlantic hurricane seasons may develop, as well as the impacts of changes in rainfall patterns, which can lead to flooding or drought, particularly across parts of Africa and Asia. Current predictions suggest East Africa is likely to see drier than average conditions over the next three months, consistent with expectations during a La Nina event, but there is no clear consensus about rainfall patterns across the rest of Africa, for example. La Nina conditions also typically lead to lower temperatures, so in the absence of this event temperatures across much of the globe are expected to continue to be above normal throughout the end of 2016 and into 2017 (see Figure 3).

2016 09 22 Emma Suckling - figure3

Figure 3: Global long-range temperature forecast for October/November/December 2016 from the UK Met Office (issued in September 2016). There is an increased probability of above normal temperatures over much of the globe during the next three months, while temperatures in the Pacific have an increased probability of being near normal. Original source:

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Double, double, toil and trouble

By Geoff Wadge

Iceland has been forcing itself on our consciousness in recent years, culminating recently in the humiliation of the English football team. There may be another unpleasant surprise up Iceland’s sleeve. Since 2010 there have been three volcanic eruptions in Iceland that have caused concern in two cases and consternation and alarm in the other. The 2010 southward dispersal of ash from the explosive phase of the Eyjafjallajokull eruption caused the panicked shutdown of half of Europe’s airports for six days. This eruption was unusual in that it lasted quite a long time – 39 days, and produced ash, some of which was transported south to Europe.

At the end of July 2016 the Icelandic Met Office issued a statement noting increased earthquake activity at Katla volcano, the neighbouring, larger, “double” of Eyjafjallajokull. This is not that unusual, but is nevertheless a concern. Katla (meaning kettle or cauldron in Icelandic) has been one of Iceland’s most active volcanoes (20 eruptions in the last 1100 years), capable of eruptions that dwarf those of its neighbour.  The last eruption was in 1918 and produced five times more ash than Eyjafjallajokull in 2010. The next eruption of Katla will almost certainly start with a swarm of earthquakes merging to a tremor signal. Such an eruption today could cause widespread disruption to aircraft, but what is the likelihood?

There is a chain of contingent factors at play. Firstly, what is the likelihood of a Katla eruption in the near future? Ten years ago this was modelled probabilistically at 20% in the next 10 years. Secondly, what magnitude and type of eruption will it be? The larger the magma mass flux, the higher the eruption column and the further the likely transport distance. Katla (like Eyjafjallajokull) has both low viscosity, basaltic magma (common, 93%) and high viscosity, silicic (dacitic) magma (rarer, 7%). The 1918 eruption was a basaltic eruption. Also the way in which these liquids are converted into fine fragments (<50 microns) in the eruption column and are advected 1000 km or more as “ash clouds” depends on the dynamics of the magma’s interaction with several hundred metres of overlying icecap, and is difficult to predict. The third main factor is the weather.  As you can see from the deposition axes of past eruptions more northerly directions are favoured by the silicic ash plumes (Figure 1a), but there have been plenty of basaltic plumes heading south to Europe from Katla (Figure 1b). The pressure chart on the first days of the 1918 eruption is shown in Figure 2. These deposition patterns are created by the proximal fallout of larger fragments from the plume, the far-travelled fraction often having more complex trajectories. The longevity of explosive lofting of ash is important here, as the conditions for southerly transport will eventually occur.

2016 09 08 - Geoff WadgeFig.1

Figure 1 (a) – Axes of the deposition of basaltic ash (tephra) from eruptions of Katla over the past 1100 years. Arrows proportional to the volume of ash. Figure 1 (b) – As in (1a) but for silicic ash deposits from Katla between 10,200 BCE and 400 CE. Figures from Futurevolc’s Catalogue of Icelandic Volcanoes (

2016 09 08 - Geoff WadgeFig.2

Fig.2  Sea-level pressure chart for the North Atlantic on the second day of the 1918 eruption of Katla, modified from;sess=b50fb0a8f44739b36e854be54e8dbf5d

Since 2010 our ability to respond to a potential Katla eruption in a less panicked manner has improved.  The UK Civil Aviation Authority relaxed the “any ash-no fly” tolerance of planes to volcanic ash, by defining low (<2 mg m-3 of ash), medium (2 -4 mg m-3) and high (>4 mg m-3) ash zones to manage flight safety. Also the Icelandic scientific community is well primed to respond (





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Earth System Modelling in the UK

By Till Kuhlbrodt

UKESMMaking climate projections for the next couple of decades is a pressing and complex task for the global climate modelling community. One of the most important purposes of modelling the future climate is to provide society and Government with projections of climate change – for instance, how will temperature, precipitation and sea level change in the UK?

The ongoing global climate change is largely driven by gases and particles that human societies emit when burning fossil fuels – carbon dioxide (CO2) stands out in this role. The physical effect of CO2 has long been understood and represented in models – this is the greenhouse effect that warms up large parts of the lower atmosphere, where we live. But carbon in the Earth System (the atmosphere, the ocean, the ice sheets and the biosphere) undergoes a complex set of chemical reactions and biological processing too. Understanding and representing these is equally important since they determine how much of the additional (emitted) carbon the Earth System processes, and how much stays in the atmosphere leading to further warming. And there are many aspects to global climate change that are not carbon-related, but equally important, that require a comprehensive view of the Earth System. What is the fate of the tropical rainforests under changing temperature and precipitation patterns? Could the Amazon rainforest die back, as some simulations suggest? How will the air quality change globally and regionally? Can we bring down the (currently large) uncertainty margins around projections of regional sea level rise?

EarthSystemIn a close-knit partnership between National Environmental Research Council (NERC) institutions, universities and the Met Office, the UK scientific community is currently building a next-generation Earth System Model: UKESM. The Department of Meteorology, in close cooperation with the National Centre for Atmospheric Science (NCAS), is contributing expertise in three fields:

  • Coupled ocean-atmosphere modelling: developing and running sophisticated computer models (more than a million lines of code) of the atmospheric and oceanic flow and dynamics.
  • Dynamic ice sheet modelling: The melting rate of the ice sheets on Greenland and Antarctica (both several km thick) currently poses the largest uncertainty for projections of sea level rise.
  • Computational Support: Running these very large computer models, along with processing and analysing their output (millions of megabytes), crucially requires support from computational scientists.

Work on UKESM started three years ago. Currently, we’re conducting and analysing test runs of the coupled Earth System Model (atmosphere, ocean, atmospheric chemistry and oceanic chemistry) and we’re planning to start production runs (for full scientific exploitation) in a couple of months. Ice sheet modelling is a much younger field and needs a little more development, but it will be integrated into UKESM next year. For more information – just have a look at our website.

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Atmospheric effects of solar eclipses

2016 08 30 - Phil Trans TA2077 banner

Solar eclipses rarely cross populated regions, but provide great opportunities both for science and science outreach when they do. The recent 20 March 2015 solar eclipse tracked across the Atlantic, giving substantial solar radiation changes in the UK and Iceland, and totality in the Faeroes. This Theme Issue of the Philosophical Transactions of the Royal Society brings together a unique series of studies on effects of eclipses on the weather, placed in the context of societal responses to eclipses. Professor Giles Harrison from this department was joint lead editor on the issue, and the journal includes contributions from many members and ex-members of the Department of Meteorology at the University of Reading on a very wide variety of topics.

Investigating effects of eclipse-induced weather changes (e.g. in surface air temperatures, wind and cloud amount) has a long history, usually exploiting observations made during the eclipse for comparison with comparable non-eclipse conditions the day before or after. New approaches to study the weather-related changes are now possible, employing high resolution numerical models of the atmosphere in which an eclipse can be turned on or off at will, combined with the extensive coverage of good quality amateur and professional weather data available. This issue includes work analysing surface, balloon and satellite observations, alongside high resolution numerical modelling studies. In doing so it defines a new interdisciplinary research area in eclipse weather, closely focussed in scope, but diverse in the work it contains.

The contents of this special issue, available online and shortly in print, is given below:

Introduction: The solar eclipse: a natural meteorological experiment: RG Harrison, E Hanna
Symbolism and discovery: eclipses in art: I Blatchford
Atmospheric changes from solar eclipses: KL Aplin, CJ Scott, SL Gray
Meteorological effects of the solar eclipse of 20 March 2015: E Hanna, J Penman, T Jónsson, GR Bigg, H Björnsson, S Sjúrðarson, MA Hansen, J Cappelen, RG Bryant
On the variability of near-surface screen temperature anomalies in the 20 March 2015 solar eclipse: MR Clark
Satellite observations of surface temperature during the March 2015 total solar eclipse:
E Good
Meteorological responses in the atmospheric boundary layer over southern England to the deep partial eclipse of 20 March 2015: S Burt
Effects of the March 2015 solar eclipse on near-surface atmospheric electricity: AJ Bennett
Terrestrial atmospheric responses on Svalbard to the 20 March 2015 Arctic total solar eclipse under extreme conditions: JM Pasachoff, MA Peñaloza-Murillo, AL Carter, MT Roman
Coordinated weather balloon solar radiation measurements during a solar eclipse: RG Harrison, GJ Marlton, PD Williams, KA Nicoll
On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse: GJ Marlton, PD Williams, KA Nicoll
Using the ionospheric response to the solar eclipse on 20 March 2015 to detect spatial structure in the solar corona: CJ Scott, J Bradford, SA Bell, J Wilkinson, L Barnard, D Smith, S Tudor
Eclipse-induced wind changes over the British Isles on 20 March 2015: SL Gray, RG Harrison
Numerical simulations of the impact of the 20 March 2015 eclipse on UK weather: PA Clark
The National Eclipse Weather Experiment: use and evaluation of a citizen science tool for schools outreach: AM Portas, L Barnard, C Scott, RG Harrison
The National Eclipse Weather Experiment: an assessment of citizen scientist weather observations: L Barnard, AM Portas, SL Gray, RG Harrison

Phil. Trans. R. Soc. A 2016 374: access content online, or purchase the print issue at the reduced price of £35 (usual price £59.50) by visiting the above web page and entering the promotional code TA 2077 when prompted, or contact:
Turpin Distribution T +44 1767 604951 E
For more information, contact:
The Royal Society
6 – 9 Carlton House Terrace, London, SW1Y 5AG
T +44 20 7451 2500

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UK drought monitoring and forecasting

By Laura Baker

After what feels like a pretty wet start to the year, it may seem strange to be talking about drought (although admittedly the warm weather over the last couple of weeks should help!). But in spring 2012, just four years ago, much of the south of England was experiencing severe drought conditions, following two years in which almost all months had lower than average rainfall (Figure 1). In this case it then proceeded to rain considerably more than average for much of the summer, preventing the drought from developing further; however had this not happened, parts of the country could have experienced severe water shortages. There are many other notable drought events that have occurred in the UK in recent decades, the most extreme being the 1976 drought where water restrictions became so severe in some areas that standpipes were introduced in the streets.

2016 07 28 Laura Baker precip_Apr10_Mar12

Figure 1: Percentage of average rainfall for April 2010 to March 2012. Source:

Drought in the UK can have severe social, economic and environmental impacts.  Although little can be done to prevent a drought, monitoring and early warning systems can reduce the vulnerability of society to these events. At the recent RMetS/NCAS conference on high-impact weather and climate, we held a workshop on the topic of UK drought monitoring and forecasting science. This was in association with two ongoing research projects: IMPETUS (improving predictions of drought for user decision-making; part of the NERC UK Droughts and Water Scarcity programme) and DrIVER (drought impacts: vulnerability thresholds in monitoring and early-warning research). Speakers from these two projects gave an overview of recent scientific advances in this field, and a presenter from the Environment Agency gave a decision-maker’s viewpoint. These presentations were followed by a lively group discussion exercise in which the following three questions were discussed (Figure 2):

  1. What are the biggest challenges in drought monitoring and forecasting at present?
  2. How should we tackle these in order to improve drought monitoring/forecasting?
  3. How can users of drought monitoring/forecast systems get more from them?

2016 07 28 Laura Baker flipboard_pics

Figure 2: Flipcharts summarizing group discussion at the workshop

Workshop attendees were from a range of backgrounds, including meteorologists, hydrologists, social scientists and industry practitioners, so the discussion was very varied.

Challenges in drought monitoring that were highlighted include issues with sparse data in some areas, meaning that accurate drought predictions and modelling of drought in these regions are difficult. Drought monitoring could be improved by using different instruments and methods to monitor rainfall and drought development, including potentially the use of drones. Better use could be made of existing data, including satellite data for monitoring soil moisture, and data that are collected on the socioeconomic impacts of drought could be more widely used.

Forecasting drought on timescales of months to seasons ahead is a challenging task. One key factor is the need to be able to forecast skilfully the atmospheric drivers of drought on these timescales. Recent advances in forecasting systems mean that there is promising skill in forecasting atmospheric circulation patterns that influence UK drought, such as the wintertime North Atlantic Oscillation. However, forecasting smaller scale features such as summer precipitation remains considerably more challenging.

In terms of users, the key issues raised were to do with communication, including the importance of consistency between sources of information, communicating the uncertainty in drought forecasts and being aware of how statements may be interpreted, or potentially misinterpreted.

The outcomes from this workshop will feed into ongoing work research UK drought, and hopefully when faced with the next 2012-type drought event we will be better placed to deal with it.

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Home is where the chart is …

By Andrew Gabey

Increasingly detailed weather forecasts will need data from far more weather stations than at present. Filling this gap is especially important for urban areas, where the built environment and the heat emitted by human activities have a complex interaction with the local climate.

Recently there’s been talk of using internet-connected home weather stations (HWS) signed up to the Met Office WOW network to help with forecasting. Greater London alone contains about 1,500 HWS compared with around 10 Met Office and Airport weather stations. So what could HWS data tell us and what are the challenges for researchers in using it?

As an example, here’s a map of air temperature recorded by HWS throughout Greater London on 19 July 2016 (smoothed data from NetAtmo and Weather Underground). This was the hottest day of the year so far with temperatures exceeding 33°C. Blotches on the map reflect HWS locations and a simple calculation fills the space in between. Outlandish readings are filtered out beforehand.

2017 07 22 Andy Gabey - Annotated

Having so many stations immediately tells us about the structure of heat through the city, which wouldn’t be obvious from using a handful of stations:

  • An urban heat island is present (and shrinking) before sunrise. This vanishes once heating gets underway and the wind picks up slightly.
    2017 07 22 Andy Gabey - heat_island
  • A slight easterly wind in the evening cools this half of the city, and the heat island is blown off to the south-west.

2017 07 22 Andy Gabey - cool_east

The big picture and temperatures here are what we’d expect given the city layout and weather conditions, but we need more information before using these numbers confidently in calculations:

  1. The environment that each station represents: Unlike the networks used here, WOW registration includes a questionnaire for contributors to describe their station’s surroundings.
  2. The accuracy and bias of each measurement: Do the blotches on the map tell us something scientific, or should they be weeded out?
  3. How to distinguish a measurement flaw from something surprising but real. Clever methods exist to weed out nonsensical measurements.

Observing stations currently used in forecasting and research are well-understood and maintained regularly, and there’s clearly new information for forecasting and urban meteorology in HWS data. The challenge for researchers is to agree how it complements existing stations, and how to rate the quality of the measurements.

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Spotlight on aviation CO2 emissions

By Emma Irvine

Climate change, resulting from emissions of CO2 amongst other factors, is a major topic of research here at Reading. This blog focusses on the emissions from one particular sector, aviation, and progress on tackling them.

I write this as the 2016 Farnborough Airshow is taking place, with major aircraft manufacturers such as Boeing and Airbus showcasing their latest technological innovations, and eco-efficiency is the buzzword. Just this week at Farnborough, General Electric tweeted that their technological developments to the engines on Boeing-737s make them 15% more fuel efficient. Not to be outdone by their US rivals, Airbus have been showing-off their A350-XWB which claims to be 25% more fuel efficient than its (unnamed) nearest competitor (although probably not when it’s doing this near vertical take-off).

Back in 2009, when 2020 seemed a long way off and 2050 the distant future, the International Air Transport Association (IATA) set itself a set of environmental targets which included: to achieve carbon neutral growth by 2020, and to reduce CO2 emissions by 50% by 2050 (relative to 2005 levels). Other international aviation organisations have similar pledges. So how is the industry doing? The European Environment Agency’s latest annual greenhouse gas report is not particularly encouraging. In 2014, emissions from international aviation rose by 1.4% while those from domestic aviation fell by 0.8%.

So while the technological developments from the manufacturers are encouraging, they aren’t enough by themselves. Amongst other initiatives to reduce CO2 emissions are increasing the use of biofuels (disappointingly, British Airways project to turn London’s rubbish into biofuel for their planes was recently scrapped) and improvements to air traffic management. In Europe, the big air traffic initiative takes the form of the Single European Sky Air Traffic Management Research (SESAR), which is aiming at a 2.8% reduction per flight in environmental impact as well as a 40% reduction in accident risk and 27% increase in capacity. Here at Reading University we are part of one of the new SESAR projects investigating the potential of reducing the overall environmental impact of European flights through optimising the routing of aircraft over Europe.  Having proven the feasibility of climate-optimised routing over the relatively unconstrained airspace of the north Atlantic, we are applying this novel concept to some of the busiest airspace in the world. With over 28,000 flights a day occurring in or passing through European airspace, optimising the routes to minimise their environmental impact will be quite a challenge.

This brings me to the ultimate in climate-optimal flight: Solar Impulse. This innovative aircraft produces zero CO2 emissions (or emissions of any kind) as it flies, being powered purely by solar energy it receives through the 17,000 solar cells in its wings. It’s currently about to embark on the final leg of its around the world tour, from Cairo to Abu Dhabi (you can follow its progress here). Setting records along the way, it made the first trans-Atlantic crossing without using fuel, flying from New York to Seville in 70 hours (at the same time achieving the more dubious accolade of ‘selfie of the year’). Although solar power is unlikely to prove the answer to aviation’s CO2 problems – at least with current technology – solar impulse is an inspiring demonstration project harnessing the power of ‘green’ energy. #futureisclean



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