Thursday, 11 September 2014

Potential influences on the United Kingdom's floods of winter 2013/14

Last winter severe flooding affected large parts of the UK. In a recent paper published in Nature Climate Change, scientists at the Centre for Ecology & Hydrology, working with colleagues from the Met Office and a number of universities, looked at the possible drivers behind the floods.

Dr Chris Huntingford, the lead author of the paper, explains:

In this paper, along with my co-authors, we have tried to provide a summary document that collates and discusses all possible drivers behind the major flood events that affected the UK last winter. It has three themes.

First, a very brief overview of the large-scale meteorological events leading up to the storms is presented. None of the individual rainfall events was unprecedented, but the weather patterns behind them persisted for three months causing a near-continuous succession of Westerly storms. This had the cumulative effect that for much of the Southern UK, the total winter rainfall was record-breaking. Preliminary analysis suggests that particularly warm ocean conditions and heavy rainfall in and around Indonesia triggered wind patterns across the Pacific that travelled northwards before ultimately drawing cold air down across the USA. This in turn forced a particularly strong and persistent Jet Stream across the Atlantic and towards the UK. The Met Office is now studying this sequence of events in significantly more detail. In our paper, we show how the winter storms affected river flows, and place the events within a historical context.

Flooding in Oxfordshire, February 2014. Photo: Julia Lawrence

Second, questions mount as to whether fossil fuel burning could have a role. We have reviewed existing research literature for Earth system factors that may be both changing through global warming, and additionally are identified as influences on storm features for the UK. As expected, this confirms how complex and inter connected the climate system is. Multiple possible UK rainfall drivers are identified that link to the state of the oceans, the atmosphere and sea-ice extent. Interestingly the recent rapid decrease in Arctic sea-ice that is widely attributed to global warming, for the UK at least is often portrayed as likely to bring more Easterly winds and colder conditions. The previous three winters had these features for some of the time, in marked contrast to winter 2013/14. Although the precise details of linkages between changing large-scale features of the climate system and UK rainfall intensity are still not fully understood, we hope our review article is a complete list of such connections. To apply that frequently used expression, we trust there are no “unknown unknowns” lurking out there we have yet to consider.

Third, we provide some thoughts on how best to proceed. Assuming that we do have a pretty good idea of all drivers expected to affect rainfall, and that require on-going computer modelling, three challenges are noted. These are: (1) the need for continued enhancement of physical process representation via ever better parameterized differential equations of the oceans, atmosphere and ice sheets, (2) increase further the numerical grid resolution of climate models, on which these equations are calculated and (3) undertake significantly higher numbers of simulations, all with slightly different initial conditions, creating a large ensemble of projections. The call for better resolution is because some characteristics of storms occur on fine spatial detail, thus needing small spacings between gridpoints on which calculations are updated. The request for large ensembles is because extremes, by definition, are rare events, and so we need to ensure that all heavy rainfall “return times” are fully sampled. This is both for pre-industrial and for raised levels of atmospheric greenhouse gases.

During the major flood events affecting much of Southern England from December 2013 to February 2014, it was inevitable that questions would be asked as to whether fossil burning could have a role. It is always (and correctly) stated that no single observed extreme event can be formally attributed to human-induced changes to atmospheric composition. But a statistic can be derived that assesses any changing probability of a particular extreme event occurring, a quantity sometimes referred to as “Fractional Attributable Risk”. By satisfying the three challenges we listed above, we will get near to stating if humans are increasing, decreasing or leaving invariant the chances of rainfall events of the type witnessed. However, even now limitations remain on computer speed and resource, and expenditure on climate research can only ever be finite. Hence an especially lively debate will now occur as to what constitutes the optimal balance between pursuing these three challenges, in order to get us most quickly towards the required answers.

Anyone studying meteorological systems, or the full Earth system, soon realizes of course how tightly coupled all features are of the climate system. In this review, by trying to collate in to a single paper the main factors affecting UK rainfall, this did though provide a timely reminder of such comprehensive interconnections. Understanding these further suggests a very interesting time lies ahead for climate change research.

Chris Huntingford

Chris Huntingford is a climate modeller based at the Centre for Ecology & Hydrology in Wallingford, Oxfordshire.

Additional information


Full paper reference: Chris Huntingford, Terry Marsh, Adam A. Scaife, Elizabeth J. Kendon, Jamie Hannaford, Alison L. Kay, Mike Lockwood, Christel Prudhomme, Nick S. Reynard, Simon Parry, Jason A. Lowe, James A. Screen, Helen C. Ward, Malcolm Roberts, Peter A. Stott, Vicky A. Bell, Mark Bailey, Alan Jenkins, Tim Legg, Friederike E. L. Otto, Neil Massey, Nathalie Schaller, Julia Slingo and Myles R. Allen (2014) Potential influences on the United Kingdom’s floods of winter 2013/14. Nature Climate Change, doi:10.1038/NCLIMATE2314

Staff page and research interests of Chris Huntingford 

New scientific review investigates potential influences on recent UK winter floods  (CEH News, 27 August 2014)

Wednesday, 3 September 2014

CEH at the British Hydrological Society National Symposium

Several CEH scientists are in Birmingham this week at the 12th British Hydrological Society National Symposium. This year’s theme is “Challenging hydrological theory and practice.”

The symposium, which takes place from 2-4 September 2014, is one of the main meetings for the UK’s hydrological community, a community in which CEH plays a key role, through both our research on issues such as water resources, floods and droughts, and our extensive hydrological data management remit.

CEH has a stand at the conference. Visitors are being shown this video highlighting the wide range of hydrological research we carry out:



Ten CEH staff are speaking at the conference on a wide range of subjects. Their presentations are as follows:

1. Natural or designer environmental flows for a changing world? Prof Mike Acreman

2. Predicting physical habitat sensitivity to abstraction. Cedric Laizé

3. Overdispersion in peak over threshold (POT) flow data and its effect on flood frequency practice.
Dr Ilaria Prosdocimi

4. The new FEH rainfall depth-duration-frequency model: results,
comparisons and implications. Lisa Stewart

5. What do we talk about when we talk about drought? Jamie Hannaford

6. Real-time modelling of surface water flooding hazard and impact at
countrywide scales. Dr Steven Cole

7. Presentation of the new CEH-GEAR dataset: fine resolution daily and monthly
areal rainfall estimates for the UK for hydrological use Dr Maliko Tanguy

8. Can land use and land management make a difference to water
availability? Helen Houghton-Carr

9. How do we want to access hydrological data over the web? Matt Fry

10. Ensuring UK hydrometric data is fit-for-purpose through a national
Service Level Agreement. Katie Muchan

Conference attendees are tweeting using the hashtag #BHS2014

Links

Conference website

Conference programme

Thursday, 21 August 2014

CEH scientists collaborating with global freshwater citizen science programme

CEH scientists working on a project investigating water pollution in urban areas have teamed up with Earthwatch to train citizen scientists in carrying out water quality monitoring. The collaboration has come about via Earthwatch’s Freshwater Watch programme, which aims to study fresh water quality around the globe by engaging employees from participating organisations as citizen scientists.

The POLLCURB project, led by CEH, is looking at how water pollution relates to change in urban areas, in particular change brought about by population growth, and what it may mean for water quality and quantity in the future.

POLLCURB is collaborating with the Earthwatch programme by training citizen scientists, in this case employees from Shell, to monitor water quality in the river Thames and two of its tributaries, the Mole and Ember, using a handheld multiparameter probe.

CEH's Mike Hutchins (centre) teaching participants
how to use the probe. Photo: Richard Sylvester / Earthwatch.

Dr Mike Hutchins of the Centre for Ecology & Hydrology is lead investigator on POLLCURB. At a recent citizen science training day at Wimbledon Common, Mike gave an overview of the project before teaching the budding citizen scientists from Shell how to use the monitoring probe, taking them into the field to gain first-hand practice.

Probe dunking. Photo: Richard Sylvester / Earthwatch.


The participants will visit the Thames sites several times over the next six months to collect data on temperature, turbidity, organic matter, algae and oxygen levels, producing a monthly dataset for each location. As well as collecting data for POLLCURB, they are also carrying out Freshwater Watch’s global parameters at each of the sites, which include collection data on nutrient levels.

Looking at the data collected. Photo: Richard Sylvester / Earthwatch.

Mike told us a little more about the value of the collaboration. He explained, "As POLLCURB is investigating how urban growth influences local water bodies I am keen to get people living in those very towns and cities involved and, in particular, for them to have the opportunity to use some of the equipment that professional scientists are currently using on a day-to-day basis.

"The data the citizen scientists are collecting will benefit me, in terms of improving the models I am using to predict river water quality, and also regulators, who will gain further knowledge of some specific rivers of interest to them."

Looking at results. Photo: Richard Sylvester / Earthwatch

Mike added, "The project with Earthwatch / Shell is flexible and I hope will gain some of its own momentum. There is potential to expand the number of sites or increase the frequency of visits, and also I am particularly enthusiastic about the scope for participants to monitor other local water bodies in which they may have a particular personal interest."

Earthwatch and CEH collaborators at one of the monitoring sites on the
Thames near Hampton Court. Photo: Mike Hutchins / CEH.


For more detailed information on the POLLCURB project, visit the project website.

Additional information


FreshWater Water has already recruited more than 1700 citizen scientists in over two dozen cities around the world. Data collected are uploaded to freshwaterwatch.thewaterhub.org

Staff page and research interests of Dr Mike Hutchins, CEH

More about the citizen science training day from Earthwatch

Posted by Paulette Burns, Media Coordinator

Monday, 18 August 2014

A weekend at Birdfair

CEH's Biological Records Centre (BRC) teamed up with the Botanical Society of Britain and Ireland (BSBI) this weekend (15-17 August 2014) to co-host a stand at the hugely popular Birdfair annual event at Rutland. Birdfair attracts more than 20,000 wildlife enthusiasts of all ages and from many different countries and was an ideal venue to encourage more people to record their wildlife sightings. Records submitted through BRC's apps and iRecord website are used in research by CEH scientists and colleagues.


Visitors were able to see how easy it is to use BRC's range of recording apps, such as iRecord Ladybirds and iRecord Butterflies (and get an exciting sneak preview of the forthcoming grasshopper app!). It was also great to see interest in the forthcoming National Plant Monitoring Scheme, which involves both CEH and BSBI. 

A number of CEH scientists were in attendance to chat about their work and about the importance of recording wildlife...



...as well as enjoy the efforts of our stand partners...


...and discover some of the other great research and volunteer efforts being highlighted at the show...


Thanks to everyone who took the time to pop by and have a chat! We hope you had a great show and continue to enjoy viewing (and recording!) wildlife.



There's an app for that...

 

Related links

 

Smartphone apps for citizen science and environmental recording

When and how to use citizen science: best practice guides from CEH

Posted by Paulette Burns, Media Coordinator

Monday, 11 August 2014

Understanding ladybird parasites

Scientists at CEH are working to better understand the natural enemies that attack ladybirds.

The arrival of the invasive alien harlequin ladybird in Britain and Ireland provided a new emphasis for research on ladybird-parasite interactions. Parasites of native ladybirds seem to find the harlequin less attractive, so will they adapt to this invader? We want to know!

Ladybird predators

There are very few predators of ladybirds. Ladybirds contain various mildly toxic and foul-tasting chemicals – their bright coloration is a warning to deter predation. But parasites do attack them, including some fascinating fungal pathogens. Two natural enemies are often considered among the most important causes of mortality in adult predatory ladybirds: the braconid wasp, Dinocampus coccinellae, and pathogenic fungi within the genus Beauveria.

Dinocampus coccinellae adult and pupa with harlequin ladybird host.
Photo: Richard Comont

Dinocampus coccinellae

The wasp Dinocampus coccinellae lays eggs in adult ladybirds – a single wasp larva hatches within the ladybird and begins to feed on the host. Eventually it emerges to spin a cocoon between the legs of the ladybird in which it has developed. This parasite-host interaction can be observed in the field: the parasite cocoon is particularly conspicuous in the spring when it can be seen attaching 7-spot ladybirds (and others) to various surfaces such as fence posts and trees.



The fungus: Beauveria

The most common pathogen attacking ladybirds is the fungus Beauveria bassiana which causes ‘white muscardine’ disease in many insects. It persists as tiny spores, usually in soil but also on tree bark or leaves. The fungus spreads by infecting overwintering ladybirds in sheltered spots such as crevices or leaf litter. Scientists at CEH have shown that ladybirds avoid places with lots of fungal spores and move away from ladybirds that succumb to the disease.

Beauveria bassiana infection (late stage) of (left to right) harlequin, 7-spot
and 2-spot ladybird adults. Photo: Helen Roy

Other parasites

Tiny scuttle flies can attack ladybird pupae. There is also a beautiful yellow fungus that grows as fruiting bodies on the surface of ladybirds.

Helping our scientists

Send your records by emailing ladybird-survey@ceh.ac.uk or upload sightings of Dinocampus to iRecord at www.brc.ac.uk/irecord/enter-Dinocampus-records

Ladybird app

The free iRecord Ladybirds mobile phone app for iPhones and Android devices makes it very easy to upload your records of ladybirds to the UK Ladybird Survey.

iRecord Ladybirds app from iTunesiRecord Ladybirds app on Google Play
Related CEH links

Harlequin ladybirds escape enemies while native species succumb 3 Dec 2013

Staff page and research interests of Dr Helen Roy


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Posted by Paulette Burns

Friday, 25 July 2014

Royal Meteorological Society members visit CEH

Members of the Royal Meteorological Society's Meteorological Observing Systems Special Interest Group have paid a visit to CEH to learn more about aspects of our monitoring work. The visitors were given a tour of our Meteorological Station at Wallingford (thankfully the weather was warm and sunny at the time!) and also heard more details about its history and observations from site manager Katie Muchan:




The visitors also heard a presentation from Dr Gareth Old about CEH's River Lambourn Observatory and research into chalk river systems:




Dr Jonathan Evans of CEH also presented on progress and early results from COSMOS-UK, the UK soil moisture monitoring network. The network will deliver real-time weather monitoring and field scale measurements of soil moisture across the United Kingdom.

Members of the RMetS Special Interest Group on Meteorological Observing Systems visit
CEH's Wallingford Meteorological Station, July 2014. Photo: Paul Fisher/ CEH


Further reading


Winter 2013/2014 rainfall records at CEH's Wallingford meteorological station 

A window on weather conditions at Wallingford

Wednesday, 23 July 2014

Surface water flood risk forecasting system operational in Glasgow as Commonwealth Games begin

As the 2014 Commonwealth Games get underway in Glasgow today (23 July 2014), organisers are probably hoping the next two weeks will stay dry and pleasant for everyone travelling to and from the various locations being used across the city. However, they’ll still be interested in the news that the Glasgow surface water flood forecasting model became operational this month – thought to provide the UK’s first operational grid-based surface water flood risk forecast with a 24-hour lead time.

Surface water flooding occurs when rainfall is unable to enter a watercourse or artificial drainage system and instead ponds or flows across the surface. In Scotland, the National Flood Risk Assessment (NFRA) estimates that 38% of flooding impacts are due to surface water (NFRA, 2011). Providing real-time surface water flood risk forecasts is challenging due to the dominant meteorological driver being convective storms, which are often highly localised and notoriously difficult to forecast.

Hampden Park, Glasgow
Hampden Park is one of the venues for the 2014 Commonwealth Games in Glasgow.
Photo by Jmorrison230582 in public domain.

The new surface water flood risk forecasting system has been developed by the Scottish Flood Forecasting Service (a strategic partnership between the Scottish Environment Protection Agency (SEPA) and the Met Office), working with the Centre for Ecology & Hydrology (CEH), Deltares and James Hutton Institute. The system builds on complementary CEH research on surface water flooding that is co-funded by the Environment Agency and undertaken within the Natural Hazards Partnership.

CEH’s Grid-to-Grid model (Moore et al., 2006, 2007; Bell et al., 2009) is a key component of the new tool. CEH scientists Bob Moore and Steve Cole provided pre-operational training in the system to SEPA and Met Office staff.

Steve Cole highlighted that, “Due to high uncertainty in forecasting the precise location of rainfall, particularly in convective situations, a probabilistic ensemble approach has been needed for the new Glasgow surface water flood risk forecast tool. A particularly novel aspect is that the tool goes beyond forecasting the likely location of surface water flooding to embrace information on potential impacts on people, property and transport. This should help emergency responders make more timely and better informed decisions.”

Further information on the new system is available from the Scottish Flood Forecasting Service, who provide regular progress updates:


More information on the Centre of Expertise for Waters (CREW) project

Surface water flood forecasting for urban communities