First Results from Weather@Home 2014 UK Flooding Experiment

We have received an impressive response from the public after the launch of our experiment on the 4^th of March. Our colleagues at the Oxford e-Research Centre, University of Oxford, estimate that nearly 1,000 new participants have subscribed to the project. Many thanks to all!

We have now analysed the first 47 simulations that participants have run and they are plotted in the Figure below.

The blue dots represent the 2013/2014 winter as observed, and for this experiment, we received 20 simulations. For the “world that might have been” experiment, we received 27 simulations, which are shown as green dots.

The smaller light green dots represent the individual patterns of sea surface temperature we estimated as the response of the climate system to man-made climate change. The smaller light green dots therefore represent the uncertainty in the human influence.

At this stage, there are not enough simulations to make any conclusions about the role of climate change in the record wet winter 2013/2014. However, we want to illustrate to the public why we need such large ensembles, which is why we will show the “results” as they evolve.

With this size of ensemble, the 2013/2014 winter as observed and as in the “world that might have been” are not distinguishable from another. Interestingly, our current wettest simulation comes from one of the  “worlds that might have been” simulations (the uppermost green dot) – but this could be entirely due to chance.

We will also compare the rainfall totals with observations. For this, we will need to calculate the rainfall total from a dataset from the Met Office for exactly the same region as the one we defined for the simulations (land rainfall for South England and Wales).

As this was a record wet winter, it has never been observed in the roughly 250 years of meteorological records, so we are looking at a 1/100-year event at least. As you can see from the figure, we are still only seeing 1/10-year events. We need more simulations to see any pattern, so please keep crunching!