So what happened to our summer?

28 08 2015

Our Chief Scientist Professor Dame Julia Slingo OBE FRS reflects on this summer’s weather and what has influenced it:

No-one can deny that we have had a pretty disappointing summer with a lot of unsettled weather and only a few warm spells, especially through July and August. Our weather has been dominated by low pressure over and to the west of the country that has brought us periods of heavy rain from the south – what we call the Spanish Plume. So what has been happening?

If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather.

So could all this have been anticipated? Seasonal forecasts for this summer suggested that temperatures and rainfall would be near normal. However, as the season progressed all the leading models around the world failed to capture the signal for unsettled weather over the UK. We all know that forecasting months and seasons ahead is still in its infancy and much more research needs to be done. On the other hand our day-to-day forecasts have been really successful in allowing us to warn of bad weather, highlighting yet again the benefits of our research that has delivered year-on-year and decade-by-decade improvements in forecasting skill. Our 5-day forecast is now as accurate as our 1-day forecast was when I started my career. This enables us to make so many decisions that keep us safe, protect our property, keep our infrastructure running and even when to go out and enjoy the sunshine!

All of this cannot happen without improvements to research and technology, and this week the first phase of our new supercomputer went live, five weeks ahead of schedule. This will enable us to provide even more accurate and relevant weather and climate forecasts to all of us, our government, emergency responders, and our many other customers at home and abroad.

The news that the BBC has decided that the Met Office won’t be their main weather provider when the current contract ends has raised the question of where will the new provider get their information from. It’s important to understand that no weather forecasting organization, whether it is a National Met Service like the Met Office or an independent company, can provide a service without a forecast, and that it is the leading meteorological agencies, like the Met Office, that build and deliver those forecasts. So whoever the BBC chooses to deliver their weather services in future, you can be sure that Met Office observations and forecasts will continue to be at the heart of them. We are committed to driving forward the skill and usefulness of our forecasts and ensuring that all of us benefit from the advances the Met Office makes in the coming years with our new supercomputer.





Met Office in the Media – 7 August 2015

7 08 2015

Earth from space

An article published today makes a number of claims about Met Office weather and climate science.

It would be difficult to cover all the points raised in this blog, but here we look at the science and facts behind a few of the assertions.

The first decadal forecast issued in 2007

We did indeed publish the first groundbreaking decadal forecast in 2007. It had two headline statements:

  1. that half of all years after 2009 would be warmer globally than the record year at that time (1998) – This is doing well so far with two out of five years (2010 and 2014) warmer than 1998 and given current temperature levels, it’s likely this will be 3 out of 6 by the end of this year, consistent with our forecast for 2015
  2. that 2014 would be 0.3 °C ± 0.21 °C warmer than 2004 (giving a range of 0.09 °C to 0.51 °C) – WMO figures show the global temperature for 2014 was 0.13 °C higher than that in 2004; which is within the range of the forecast

Adjustments to global temperature data

The article says we adjust our temperature figures ‘without justifying why it is scientifically appropriate’. In fact, numerous peer-reviewed science papers from research centres across the world provide detailed explanations of how and why datasets are adjusted to ensure they are as accurate as possible. This is available for anyone to view and analyse.

The conclusion that the world has warmed is supported by independent analysis of global temperature data.

European heatwaves

We published a paper stating heatwaves like that seen across Europe in 2003 would become more frequent under climate change. Subsequent observations back up these conclusions; 2006 saw comparable heat in the UK, 2010 saw intense heat across eastern Europe, and there’s been a prolonged heatwave across much of Europe this year (although not in the UK).

Weather extremes

Met Office research supports climate research centres around the world which concludes we expect more extremes of heat and rainfall as the world continues to warm. The article says this ‘simply hasn’t happened’ but in fact, research shows there has been an increase in both. While here in the UK, we have also seen an increase in the number of temperature and rainfall records.

The article also states ‘the Met Office did all it could to claim the rain that caused last year’s exceptional flooding… was the worst ever recorded.’ We’ve done studies (here and here) of the exceptional rainfall in winter 2013/14., which across southern England was one of the, if not the most, exceptional periods for winter rainfall in around 250 years. Here’s a fuller research piece about the winter 2013/14 storms.

Greenland ice

The article says that we claimed Greenland ice would melt in future due to global warming. We did, and we were clear that it would take thousands of years to happen, not ‘any time soon’. Observations show Greenland has been losing 300 gigatonnes (1 gigatonne is 1000,000,000 tonnes) of ice a year over the last 12 years and research shows surface temperatures have clearly risen.

Other claims

A series of other claims are made in the article, mostly focusing on our forecasts over seasonal to decadal timescales. The Met Office is at the forefront of this pioneering area of research and we are increasing skill in this area.

According to standards set by the World Meteorological Organization the Met Office is ranked as the most accurate global met service in the world. We will continue our research in collaboration with our global scientific partners to improve this vital area of science.





Met Office scientists to feature in BBC Horizon programme ‘Global Weirding’

27 03 2012

BBC Horizon will broadcast ‘Global Weirding’ on BBC Two tonight at 9pm, exploring the science behind why the world’s weather seems to be getting more extreme and if these patterns are a taste of what is to come.

Horizon say: “Something weird seems to be happening to our weather – it appears to be getting more extreme. In the past few years we have shivered through two record-breaking cold winters and parts of the country have experienced intense droughts and torrential floods. It is a pattern that appears to be playing out across the globe. Hurricane chasers are recording bigger storms and in Texas, record-breaking rain has been followed by record-breaking drought.

“Horizon follows the scientists who are trying to understand what’s been happening to our weather and investigates if these extremes are a taste of what’s to come.”

The producers of the programme visited the Met Office headquarters and Operations Centre in Exeter to film for the programme at the end of last year, interviewing Adam Scaife, Head of Monthly to Decadal Forecasting and Helen Chivers, a Met Office Forecaster.  In the programme we discuss the science being undertaken here at the Met Office into the effects of Climate Change on ourt weather including the effects of Arctic sea ice depletion on European winter weather, and our role in forecasting extreme weather for the UK.

Adam Scaife and Helen Chivers from the Met Office appear in the programme

Other contributors to the programme include Mike Lockwood (University of Reading) on solar observations, Kerry Emmanuel (MIT) on hurricanes and Katharine Hayhoe (Texas Tech University) on extreme wet and dry conditions in Texas.

This weeks Radio Times also previewed the programme saying:

“This week’s Very Big Number from Horizon: the Met Office’s computer can do one hundred trillion calculations — a second. It needs to, in order to process the gouts of data gathered from satellites, data which means, we’re told, that a five-day forecast today is as accurate as a one-day forecast was 30 years ago. (Were we so long-suffering in 1982?)

All this technology isn’t to feed some quaint British obsession with weather, it’s to keep track of increasingly freakish extremes in meteorology, not just here but around the world: from record rains in Scotland to droughts in Texas and a boom in hurricanes. Scientists are trying to get to grips with it all and Horizon follows them, in one amazing scene, right into the heart of the storm.”





Met Office in the Media: 20 March 2012

20 03 2012

There has been widespread coverage of a scientific paper detailing an update to the joint Met Office Hadley Centre and University of East Anglia, HadCRUT global temperature dataset. The paper is published in the Journal of Geophysical Research.

Compiled from temperature observations obtained over land and sea, HadCRUT is used as a basis for a global temperature record going back to 1850. The latest version of the dataset, called HadCRUT4, includes newly available data – notably adding much more information from the sparsely observed northern higher latitude region. Differences in the way sea surface temperature observations have been collected have been taken account of and the new version also provides much more detail on uncertainty.

The amendments do not change the long-term trend. Annual global mean temperature record under HadCRUT3 and HadCRUT4 can be found on the Met Office website.

The BBC reported on the ‘Update for world temperature data‘, while the Telegraph reported ‘World warmed even more in last ten years than previously thought when Arctic data added’. Elsewhere the Mail Online reported that ‘New temperature record confirms world HAS warmed 0.75C since 1900‘. Other reports included the Herald, Scotsman, ClickGreen and the New York Times.

The Telegraph and CCRMagazine.com have written about the Government publication of the Terms of Reference for the Data Strategy Board & the Public Data Group. The Met Office, as part of the Public Data Group, with Ordnance Survey, Land Registry and Companies House is already making data available allowing the public and businesses access to our data that will allow it to be re-used and repackaged.

Real-time weather observation and forecast datasets made available for the first time by the Met Office in November are an example of the kind of data that will promote the creation of high-value businesses, while widening the marketplace and empowering the individual citizen. Following this Golfmagic.com reports on how Marriot Golf has launched a new app which has Met Office weather forecasts embedded into the App.

In other news the BBC reports on the British team that is developing a car that will capable of reaching 1,000mph. The Met Office is supporting Bloodhound SSC (SuperSonic Car), by providing scientific monitoring of the weather ahead of any record attempt. The Mail Online and the Observer both report on the inclusion of Space Weather in the National Risk Register. The Met Office is working with partners in the UK and the US on developing an operational space weather service.





Has spring sprung?

21 02 2012

This week temperatures are forecast to reach 16 °C, the mildest of the year so far. This is unseasonably warm for February, which usually reaches highs of around 8 °C on average.

So is this the first sign of spring? Meteorologically speaking, no. For statistical purposes in meteorology, spring begins on the 1 March and ends on the 31 May. For many people though, spring begins on the date of the spring equinox, 20 March.

Although spring can be determined by calendar dates, the natural variability within the atmosphere means that, as far as the weather is concerned, year to year differences vary widely.

However, looking beyond the year to year differences we see that our climate is changing, records show spring has advanced 2-6 days per decade in the UK. Those with gardens need to start cutting their lawns almost two weeks earlier than they did in 2001.

Research undertaken by the Met Office Hadley Centre has also confirmed that the growing season of plants is likely to increase by around 40 days by 2080, due to the earlier start to spring and later end to autumn.

The mild but wet and windy weather is set to continue until the weekend, visit the website for your local forecast.





What’s bringing the cold weather to Europe and the UK?

9 02 2012

The current cold weather across Europe is in sharp contrast to the mild, wet and windy conditions across much of Europe through December and January. The cause of the cold conditions is the development of a large ‘blocking’ anticyclone over Scandinavia and north-western Russia. Easterly winds on the southern edge of this system has transported cold continental air westwards, displacing the more usual mild westerly influence from the Atlantic Ocean all the way to the British Isles.

Global land and sea surface temperature anomalies for 1-5 February 2012

Global land and sea surface temperature anomalies for 1-5 February 2012

A ‘blocking anticyclone’ can be thought of being like a very large boulder in a stream. This boulder acts like a dam, stopping the flow of the stream.  In this instance a block stops the more normal westerly flow that brings milder conditions, allowing colder conditions to win out from the east.

The origin and persistence of blocks has been a subject of much research, and unfortunately we are still not absolutely clear on why we see blocks form. What we do know though is that the origins of this large blocked pattern across Europe can be traced back to the appearance of two individual regions of mid-latitude blocking over central Russia and the Bering Sea in mid January. Over the next two weeks, these two regions merged together to form the ‘block’ we see now.

The appearance of significant blocking after a long absence is reflected in the strong decline of the Arctic Oscillation (AO) index, which effectively describes a state in the atmosphere where the flow of westerly winds is either stronger or weaker than usual in the northern hemisphere. It is currently in its negative phase, meaning the westerly flow is less strong than normal. The switch to a negative AO was seen in late January and highlights the dramatic change from generally strong westerly flow to the much less westerly or even easterly blocked state.   

Despite the general unpredictability of blocking patterns, there were potential signs of an increased risk of a significant cold weather several weeks ago when the high altitude winds began to weaken in longer-range forecasts. We now understand that there is a clear link between the weakening of these high altitude winds and the surface weather that operates on monthly timescales and in situations like this it can provide a ‘window of opportunity’ for monthly forecasts to warn of increased risk. Based on this understanding, the Met Office 16 to 30 day forecast has reflected the increasing risk of cold conditions since mid January.

Met Office Hadley Centre scientists have investigated and demonstrated a clear stratospheric influence on surface climate during these events, with easterly winds burrowing down through the atmosphere to affect the jet stream and surface climate. The result is a switch from mild westerly Atlantic flow over Europe to easterly winds with an increased risk of cold extremes.

Weakening of the jet stream in the Stratosphere can allow easterly winds to move down through the atmosphere to give cold easterly winds at the surface. This can result in cold and snowy weather across the UK.

A similar situation occurred at this time of year in 2009 when we had significant snowfall across the UK and other parts of Europe, following a strong breakdown of the high altitude jet. Although only some cold winter spells can be predicted in this way, other recent winters such as 2006 and 2010 have also shown clear examples of the effect.





Met Office in the Media: 29 January 2012

29 01 2012

Today the Mail on Sunday published a story written by David Rose entitled “Forget global warming – it’s Cycle 25 we need to worry about”.

This article includes numerous errors in the reporting of published peer reviewed science undertaken by the Met Office Hadley Centre and for Mr. Rose to suggest that the latest global temperatures available show no warming in the last 15 years is entirely misleading.

Despite the Met Office having spoken to David Rose ahead of the publication of the story, he has chosen to not fully include the answers we gave him to questions around decadal projections produced by the Met Office or his belief that we have seen no warming since 1997.

For clarity I have included our full response to David Rose below:A spokesman for the Met Office said: “The ten year projection remains groundbreaking science. The complete period for the original projection is not over yet and these projections are regularly updated to take account of the most recent data.
“The projections are probabilistic in nature, and no individual forecast should be taken in isolation. Instead, several decades of data will be needed to assess the robustness of the projections.

“However, what is absolutely clear is that we have continued to see a trend of warming, with the decade of 2000-2009 being clearly the warmest in the instrumental record going back to 1850. Depending on which temperature records you use, 2010 was the warmest year on record  for NOAA NCDC and NASA GISS, and the second warmest on record in HadCRUT3.”

Global average temperatures from 1850 to 2011 from the three individual global temperature datasets (Met Office/UEA HadCRUT3, NASA GISS and NOAA NCDC

Furthermore despite criticism of a paper published by the Met Office he chose not to ask us to respond to his misconceptions. The study in question, supported by many others, provides an insight into the sensitivity of our climate to changes in the output of the sun.

It confirmed that although solar output is likely to reduce over the next 90 years this will not substantially delay expected increases in global temperatures caused by greenhouse gases. The study found that the expected decrease in solar activity would only most likely cause a reduction in global temperatures of 0.08 °C. This compares to an expected warming of about 2.5 °C over the same period due to greenhouse gases (according to the IPCC’s B2 scenario for greenhouse gas emissions that does not involve efforts to mitigate emissions).  In addition the study also showed that if solar output reduced below that seen in the Maunder Minimum – a period between 1645 and 1715 when solar activity was at its lowest observed level – the global temperature reduction would be 0.13C.





Climate change and extreme weather

4 12 2011

As the first week of COP17 in Durban draws to a close Peter Stott, Head of Climate Monitoring and Attribution at the Met Office Hadley Centre was interviewed by OneWorld TV about how our climate is changing today and what this means for the risks of extreme weather around the world.

The Met Office is at the UN Climate Change Conference supporting the UK Department for Energy and Climate Change in it’s negotiations on behalf of the UK. This means that we provide independent scientific advice on which sound negotiations can be based.

Whilst here at COP17, our scientists have also been working with the UN World Food Programme exploring food security issues in Africa today and in the future. Our scientists have also been speaking with other African scientists about the science of climate change for their own countries and how we can work together on issues such as understanding regional climate change, regional climate modelling and developing robust long-range forecasts on which many people in these countries rely.





Met Office in the Media: 01 July 2011

1 07 2011

The Independent has today reported about a partnership between the Met Office and NCAR and other leading climate scientists to investigate exceptional weather events to see whether they can be attributable to global warming caused by greenhouse gas emissions. In ‘Extreme weather link ‘can no longer be ignored’ Steve Connor reports on the Attribution of Climate-related Events (ACE) project which held its first workshop in August 2010 in Colorado.

Peter Stott, Head of Climate Monitoring and Attribution at the Met Office Hadley Centre said:  “We’ve certainly moved beyond the point of saying that we can’t say anything about attributing extreme weather events to climate change. It’s very clear we’re in a changed climate now which means there’s more moisture in the atmosphere and the potential for stronger storms and heavier rainfall is clearly there.”

More information on this work can be found in:

Climate change: how to play our hand? (Guardian)
Pakistan floods – More than just an active monsoon? (Met Office News Blog)

Elsewhere the Daily Mail and other papers have reported on a research paper that has suggested that aircraft taking off and landing increase the amount of snow or rainfall around airports, where due to the variability in weather is likely to mask any phenomenon within the observations.

 

 





Met Office Chief Scientist nominated for Public Servant of the Year in Women in Public Life Awards

7 06 2011

Prof. Julia Slingo OBE has been nominated for Public Servant of the Year in Women in Public Life Awards 2011.

Her citation from the Women in Public Life Awards says:

Professor Julia Slingo OBE is widely recognised as a world-leading scientist in her own right. Since February 2009 she has served as Met Office Chief Scientist providing inspirational leadership of science in the Met Office, and in the wider UK and international community. A leading authority on weather and climate science, she frequently speaks to her peers, the media and the public to promote a common understanding of the issues and impacts associated with natural hazards, weather and climate science. Her previous roles include Director of Climate Research in the National Centre for Atmospheric Science where she led climate research from UK academic institutions, and Founding Director of the Walker Institute for Climate System Research at the University of Reading. Julia is also the first woman to be President of the Royal Meteorological Society, a post she held since 2008.

‘Julia is one of very few women to join the influential group of Government chief scientific advisers. Last year’s volcanic eruption in Iceland and subsequent closure of European airspace provided a keen test of her leadership and communication skills, in providing the scientific advice underpinning the UK’s response to the crisis. Throughout this rapidly changing event, she provided Government with expert advice on the distribution of volcanic ash across international airspace. She also provided the leadership needed to quickly implement new science to meet the changing requirements of the aviation community. Importantly, despite considerable pressure from the media and a number of understandably worried airlines, Julia ensured advice was impartial, evidence based and delivered with the highest scientific integrity. This has been acknowledged through a Select Committee enquiry. Julia’s passion and drive for her science, and its impacts on people, is infectious. This passion is never more evident than when she is briefing and advising Government officials and politicians, or speaking in the media. In the last year she has, for example, appeared on BBC Newsnight and provided an authoritative voice for the Independent and Nature on a range of subjects including the flooding in Pakistan and Australia, and the cold winter conditions in the UK. Recognising Julia’s major role during an unprecedented year of global natural hazards, the American Geophysical Union invited her to deliver the prestigious AGU Frontiers of Geophysics keynote lecture to its annual conference in December 2010.’

The Awards celebrate women leaders in society and seek to recognise and promote the work of women in politics, business, the civil service and community leadership. The ceremony will take place on 13 September.








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