On 27th February 1903 a major windstorm hit the UK and Ireland, known as Storm Ulysses.
The 20th Century Reanalysis (20CRv3) includes a modern reconstruction of the storm, created by assimilating available observations of surface pressure into a state-of-the-art weather forecast model.
There is a problem however. The number of available observations over north-west Europe is limited as most have never been digitised from the original hand-written paper sources. Recently, the WeatherRescue.org project rescued millions of observations, allowing us to examine the value of this new data by rerunning 20CRv3 with the new data added.
The animation below shows Storm Ulysses in the original version of 20CRv3 (left) and an improved version (right) with added observations (black dots). The contours are of sea level pressure and the colours are the wind speed at 10m, with blue arrows showing the wind vectors. The new rescued observations have reduced the minimum pressure, which is also simulated with more confidence.
But, is this an improvement? The wind ‘footprint’* for Storm Ulysses shows an increase in simulated wind speed when adding the new pressure observations, and this is now a far more credible simulation given the known damage that occurred during this storm (also see this photo).
* This figure shows the maximum wind speed from the 3-hourly simulated data so is probably an underestimate of the maximum sustained wind speed.
John Tyndall (c.1822–1893), Irish physicist, mountaineer, and public intellectual, is best known for his work on the absorption of heat by gases such as water vapour and carbon dioxide in the atmosphere (and for explaining why the sky is blue). Seen in retrospect, he is a critical figure in the history of climate science. Yet this retrospective view hides a complex, and in many ways more interesting story.
In The Ascent of John Tyndall, the first major biography of Tyndall for more than 70 years, I unpick the motivations behind Tyndall’s work on the absorption of heat by gases, which started in 1859, and the manner in which he interpreted them.
Guest post by Roland Jackson Continue reading John Tyndall: founder of climate science?
For twenty years between 1883 and 1904, three intrepid weathermen lived at the top of Ben Nevis – the highest mountain in the UK – experiencing some of the worst weather the country has to offer.
Every hour, day and night, winter and summer, and whatever the weather, one of them would step outside and check the meteorological instruments, diligently recording the observations.
This was a uniquely Victorian-era endeavour. Science for the sake of science. Rather than exploring the world’s polar regions like some of their contemporaries, these Weathermen were exploring the atmosphere.
There was simply no other way of learning in detail about how the atmosphere changed with height without living at the top of a mountain. So that is what they did.
Continue reading Weathermen of Ben Nevis
The term ‘Little Ice Age’ refers to a period of cooler temperatures between around 1400 and 1850, although a range of dates are used. This climate feature has been inferred from various types of direct and indirect evidence, but it is still not clear how widespread these cooler temperatures were.
A new article by Lockwood et al explores some of the commonly used indirect evidence such as paintings and the occurrence of ‘frost fairs’ on the Thames. We also address the common assumption that the cooler temperatures were solely due to a reduction in solar activity (the Spörer and Maunder minima). Although this assumption is almost certainly wrong, the two features are sometimes considered to be synonymous.
Continue reading Frost fairs and the Little Ice Age
The UN Paris Agreement on climate change aims to ensure increases in global temperature are less than 2°C above ‘pre-industrial’ levels, with an aspirational 1.5°C limit. However, the ‘starting line’ of the pre-industrial era is not defined by the UN agreements, or by the Intergovernmental Panel on Climate Change (IPCC).
A new analysis by an international team of researchers aims to better define the pre-industrial baseline, informing the world’s decision makers on the required limits to greenhouse gas emissions needed to meet the terms of the Paris agreement. The study concludes that 2015 was likely the first time in recorded history that global temperatures were more than 1°C above pre-industrial levels. Continue reading Defining ‘pre-industrial’
We are all familiar with the usual metrics used to highlight that the climate is changing: surface air temperatures, sea level, sea surface temperatures and ocean heat content all rising, glaciers retreating, Arctic sea ice declining etc. But, there are also many other less well known sources of information about how our climate is changing, and many involve ‘citizen scientists’, who often didn’t realise the potential long-term benefits of the data they were collecting. Continue reading Observing long-term climatic changes with unusual sources
Almost exactly 30 years ago a paper by Farman, Gardiner & Shanklin appeared in Nature describing the loss of ozone in the Antarctic and suggesting that the presence of chlorine compounds high in the cold polar winter atmosphere were responsible. Continue reading Ozone birthday
2014 was a warm year for much of Europe and the globe, and may end up being the warmest year on record globally. But, no-one experiences a global mean temperature directly, so how about more locally? Can the signal of a warming climate be seen?
Continue reading Central England Temperature in 2014