Category Prediction
Visualising input spaces using emulators
In a previous post, I looked at some of the ways we could visualise the input space of climate models, when they are constrained to produce behaviour that looks something like the real world. I used parallel co-ordinates plots and pairs plots to visualise the high (32) dimensional input space of the JULES land surface […]
Visualising weird input spaces
I’ve been working on a fairly large (~500 member) perturbed-parameter ensemble of the land surface model JULES. The model simulates the global historical land surface, and each ensemble member is forced by the same global reanalysis on the HadGEM2 grid scale. Differences in the model output are therefore caused by the different values of the […]
Sensitivity analysis with R
After last week’s post, I thought it might be useful to have some practical examples of how to do sensitivity analysis (SA) of complex models (like climate models) with an emulator. SA is one of those things that everyone wants to do at some point, and I’ll be able to point people here for code […]
Choosing your next design point
You can use the R package DiceOptim to choose the next point to run your expensive simulator. Here’s a gif of function EGO.nsteps() in action, choosing one point at a time, with an initial design of three points. It doesn’t behave in exactly the way I expected, putting lots of points in that well […]
On the existence of the hiatus
A new paper by Karl et al. in Science makes a spirited argument that there really is no “hiatus” or “slowdown” in global surface temperature warming. The paper focuses on some of the more technical details of bias correction in the temperature data record, rather than on the dynamics of the climate. It is from a […]
A brief comment on timing
In a comment on Mora et al. (2013), we highlight some errors the authors make in calculating and expressing the uncertainty in the timing of “climate departure” – the time at which a particular place on Earth will see a climate unprecedented in the historical record. There is a reply by the authors of the […]
The great thing about UQ is we know how to spell it
It’s been pretty busy round these parts, here are a few notes from the last month or so. Natural variability – Energy budget Our paper on natural variability in the Earth’s energy budget got a nice write-up from John Abraham in the Guardian. Mat Collins happened to be passing, and took a nice picture of […]
When will the summer Arctic be nearly ice free?
This is a nice short and pleasingly informal summary of the latest work on predictions of loss of summer sea ice in the Arctic, published in GRL. The paper is perhaps more useful as an up-to-date literature review than an analysis paper, which is perhaps a kinder way of saying what Stoat says. The paper […]
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