Record UK rainfall in winter 2013-14 caused by tropics, stratosphere and climate warming

rainfall
Credit: Teodoro S Gruhl/public domain

New research has revealed the causes of the UK's record rainfall and subsequent flooding during the 2013-14 winter.

Using carefully tailored atmosphere/ocean model experiments, the research team found that a combination of unusual tropical conditions, the stratospheric polar vortex, and climate warming were behind the , which led to severe flooding across many parts of the UK.

The team, comprising researchers from the Met Office and the University of Oxford, publish their results today in the journal Environmental Research Letters.

Lead author Jeff Knight, from the Met Office, said: "The record in the UK in 2013-14 resulted from persistently very low atmospheric pressure over the North East Atlantic Ocean, which was part of a disrupted in the atmosphere across the Northern Hemisphere.

"We assessed contributions to conditions near the UK from various possible remote forcing regions, using sets of experiments with state-of-the-art atmosphere/ocean models. In these regions we constrained winds and temperatures to be similar to those observed in winter 2013-14. The results show that influences from the tropics were likely to have played a significant role in producing the record UK rainfall, including a role for the tropical Atlantic sector."

To assess the role played by climate change in the unusual conditions, the research team turned to historical meteorological observations to conduct an analysis segregating the contribution of pressure patterns and other factors, like ocean temperatures, to rainfall variability.

Jeff Knight said: "Our analysis shows that climate change likely did make a contribution to the record rainfall in 2013-14 through a long-term increase in UK winter rainfall that is not associated with changing weather patterns. The size of this contribution is only 10-15% of the excess rainfall actually observed in winter 2013-14, however, so the main cause of the extreme UK winter appears to be the unusual atmospheric dynamics linking the UK with the tropics and the stratosphere."

"However, what is much more difficult to answer is whether climate change has already altered the weather patterns themselves. If the risk of the type of low-pressure patterns that brought so much wet weather has already increased then 's effect might be considerably larger. It is also worth noting that even a small shift in could make the frequency of events like winter 2013-14 substantially greater in the future ."


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More information: Jeff R Knight et al, Global meteorological influences on the record UK rainfall of winter 2013–14, Environmental Research Letters (2017). DOI: 10.1088/1748-9326/aa693c
Journal information: Environmental Research Letters

Citation: Record UK rainfall in winter 2013-14 caused by tropics, stratosphere and climate warming (2017, June 22) retrieved 24 May 2019 from https://phys.org/news/2017-06-uk-rainfall-winter-tropics.html
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Jun 23, 2017
Stop attributing transitory weather events to global warming. California had a drought and it passed. The global warming kooks pronounced that the Great Lakes were drying up. Lake levels are higher than ever. Do these cranks ever get tired of being wrong?

Jun 23, 2017
Current weather is climate + some transitory "noise". By definition, when the climate changes, your weather will change. Claiming that climate change/global warming can't be, at least in part, the cause of "transitory weather events" is, therefore, just a way to proclaim your profound ignorance. (To be honest, it could be incompetence rather than just ignorance, but I'm trying to give you the benefit of the doubt.)

Jun 23, 2017
Current weather is climate + some transitory "noise". By definition, when the climate changes, your weather will change.
...........and just like all AGW Enthusiasts, when you come to a fork in the road & you don't know which road to take........you take the fork; speaking out of both sides of your mouth you try to kid us that is the scientific method.


Jun 23, 2017
Stop attributing transitory weather events to global warming.
Actually they attributed this weather event to -
a combination of unusual tropical conditions, the stratospheric polar vortex, and climate warming


But it is good to know that you - sitting behind your keyboard - know better than they. Perennial hubris!

Jun 23, 2017
Phys.org changes the very hesitant "could" of the paper to "does" cause climate change. Phys.org is basically a journalistic liar. Read the paper the authors are basically putting in the required crap of climate change to fill in the box. The Phys.org liars need to sign their names. Read between the lines of 10-15% change of climate change contributing in their model. Hogwash

Jun 23, 2017
Additional note, the climate change is linked to "atmospheric moisture". All AGW nuts make the link to CO2. H2O runaway GHG.

Jun 23, 2017
Additional note, the climate change is linked to "atmospheric moisture". All AGW nuts make the link to CO2.

You've said before that you have no understanding of climate science, but this is incredibly silly. Water vapor is a condensable gas. It requires something else to keep the atmosphere warm or it will condense out of the atmosphere. That "something else" is known to be, for at least the last 50 years, non-condensable GHGs, primarily CO2 (https://www.acs.o...co2.html ). Water vapor is very important, but unlike CO2 it can only act as a feedback. Increased levels of CO2 cause some warming and water vapor increases in the atmosphere causing more warming. Without something like CO2 or the sun to warm things up, water vapor wouldn't increase in the atmosphere and would do nothing.

Cont.

Jun 23, 2017
H2O runaway GHG.

Don't be so alarmist. A runaway GHG effect really isn't likely to happen on earth (https://www.skept...nced.htm ). Regardless, water vapor still needs something else to start any warming before it can have any effect. After all, it's just a feedback.

Jun 24, 2017
ZZ5555 did you read the paper?

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