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Constraining the carbon cycle in a land surface model – a talk for EGU23
I’m attending the EGU 2023 assembly this week, and gave a talk on our latest paper Constraining the carbon cycle in JULES-ES1.0. Attending online works fine, but doesn’t give you all the bonuses of meeting in person, getting the lowdown on the coolest talks coming up, and catching up with old colleagues and friends. One […]
Uncertainty quantification and exascale computing in climate science
I was asked to sit on a discussion panel at this meeting on uncertainty quantification (UQ) with exascale computing. I prepared a short statement (below) on future challenges for UQ at exascale, but I would have made a slightly a longer one (below that) if there was time. A great resource for thinking about the […]
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 […]
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 […]
Internal variability in surface temperature and the hiatus
Our paper Quantifying the likelihood of a continued hiatus in global warming is published today in Nature Climate Change. Here is the New Scientist take, the Carbon Brief take, and the Met Office Research News article. Chris Roberts took on a huge task, processing massive amounts of data in the CMIP5 climate model archive, and leading […]
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 […]
A brief observation on statistical significance
This has been on my mind for a while. I think the observation is best summed up as: If somebody asks if something is statistically significant, they probably don’t know what it means. I don’t mean to offend anyone, and I can think of plenty of counter examples*, but this is borne out of long […]
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