Similar increases in heavy rainfall have now also become evident in spring and, to a lesser extent, autumn.
A previously reported reduction in heavy summer rainfall appears to have ended during the 1990s, with observations for the last decade indicating a return to more typical amounts of intense rainfall in summer.
The results will inform other work currently being carried out on flood risk and the impact of extreme weather events. As surface run-off depends on rainfall intensity and frequency, changes in intense rainfall events will impact strongly on floods.
The UEA study was funded by the Natural Environment Research Council (NERC) as part of the Flood Risk from Extreme Events (FREE) programme, which aims to improve predictions of floods minutes-to-weeks and seasons-to-decades ahead, by using environmental science to investigate the physical processes involved in generating extreme flooding events.
Using data from more than 600 rain gauges around the UK, from as far back as 1900 to as recently as 2006, Douglas Maraun, Tim Osborn and Nathan Gillett, of the university’s Climatic Research Unit, classified every day’s measured precipitation into one of 10 categories of rainfall intensity, from drizzle to a downpour. They then analysed how the amount of precipitation in each category has changed over time. In winter, for example, the amount of precipitation falling in the heaviest category has increased over the last 40 years in all regions of the UK.
The work, published this week in the International Journal of Climatology, updates and extends previous studies by Dr Osborn and colleagues, using five-times as many rain gauges and looking at measurements over a longer time period.
Their classification took into account the typical differences in rainfall between summer and winter and across different regions of the country. In parts of East Anglia, for example, heavy rain meant at least 20mm falling on a single summer day, while in winter, 10mm in a day was sufficient to reach the heaviest category. For some locations in the north-west Highlands of Scotland, rain or snow falls of at least 30mm in summer and even 60mm in winter were the minimum required to count towards the heaviest category.
This new, more extensive study, using up-to-date records, supports the existence of a long-term increase in winter precipitation intensity that is very widespread across the UK. In the late 1960s, about seven per cent of the UK’s winter precipitation came from heavy rain or snow events, while in the last 10 years that figure has been about 12 per cent.
Until the late 1990s, most areas of the UK had seen a decreasing contribution of extreme rainfall during the summer. The updated measurements indicate that this trend towards lighter summer rainfall reversed during the last decade, but it is too early to tell whether this new trend will continue into the future.
“So far it is not clear what causes these trends and variations. In the next stage of our study, we will be looking at possible physical mechanisms and whether man-made global warming is contributing,” explained Dr Maraun.
Press Office | alfa
Value from wastewater
16.08.2017 | Hochschule Landshut
Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Information Technology