Archive for weather forecasting

AI in a storm [cover]

Posted in Books, pictures, University life with tags , , , , , , , , , , , , , , , , , , on October 6, 2026 by xi'an

Nature tidbits

Posted in Books, pictures, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , on January 9, 2025 by xi'an

From the 12 December issue, lots of AI entries in Nature (soon moving to NAIture??), from the arrival of AGI, artificial general intelligence, and the usual barren call for companies to take responsibility (!) and equally repeated pious wishes for (better) controlling the incoming “human intelligent” AIs, to the two year anniversary of ChatGPT, which came as a significant support to non-native English speakers, if raising concern about the privacy losses in delivering unprotected data to the model,  to the incoming dearth of data to feed AIs (duh? why would new data be necessary for new AI systems?), with the danger that using AI generated data to train new AIs is not good being repeated anew, to the poor performances of LLMs on African languages, and the correlated dearth of funding in Africa, to DeepMind doing better than weather agency supercomputers to predict weather on a 15 day window, including extreme weather events (not much of a surprise, as climate change does not mean that history of past weather patterns cannot be exploited) albeit the probabilistic nature of the forecast seems to derive from the randomness of the starting conditions, hence depends on the choice of that distribution, to the (unsurprising) 50% productivity boost in design in a material science company afforded by seconding (or supplanting!) researchers with AI tools, to the poor design of bar plots (inc. Nature) that induce misunderstandings. A fair degree of double entries when considering the earlier 5 December issue, also read in the plane, with again fossilized poo, AI soon reaching human intelligence level (??),  and the AI computing gap between academy and industry. Beside this AI frenzy, a news article reporting on the EU trying to create an applied research council equivalent to what the ERC succeeded for academic research. (And I will not mention the digestive track article further than pointing out it added bromalite, cololite, and regurgitalite, to my digestive vocabulary!)

it did get worse!

Posted in Statistics with tags , , , , , , , , , , on October 19, 2024 by xi'an

off to Edinburgh [and SMC 2024]

Posted in Books, Mountains, pictures, Statistics, Travel, University life with tags , , , , , , , on May 12, 2024 by xi'an

IMG_9351Today I am off to Edinburgh for the SMC 2024 workshop run by the ICMS. Looking forward meeting with long time friends and new ones, and learning about novel directions in the field. And returning to Edinburgh I last visited in 2019 for the opening of the Bayes Centre. Hoping to enjoy the nearby Arthur’s Seat volcano and maybe farther away Munroes, depending on the program, train schedules, and…weather forecasts!

simulating the pandemic

Posted in Books, Statistics with tags , , , , , , , , , , , on November 28, 2020 by xi'an

Nature of 13 November has a general public article on simulating the COVID pandemic as benefiting from the experience gained by climate-modelling methodology.

“…researchers didn’t appreciate how sensitive CovidSim was to small changes in its inputs, their results overestimated the extent to which a lockdown was likely to reduce deaths…”

The argument is essentially Bayesian, namely rather than using a best guess of the parameters of the model, esp. given the state of the available data (and the worse for March). When I read

“…epidemiologists should stress-test their simulations by running ‘ensemble’ models, in which thousands of versions of the model are run with a range of assumptions and inputs, to provide a spread of scenarios with different probabilities…”

it sounds completely Bayesian. Even though there is no discussion of the prior modelling or of the degree of wrongness of the epidemic model itself. The researchers at UCL who conducted the multiple simulations and the assessment of sensitivity to the 940 various parameters found that 19 of them had a strong impact, mostly

“…the length of the latent period during which an infected person has no symptoms and can’t pass the virus on; the effectiveness of social distancing; and how long after getting infected a person goes into isolation…”

but this outcome is predictable (and interesting). Mentions of Bayesian methods appear at the end of the paper:

“…the uncertainty in CovidSim inputs [uses] Bayesian statistical tools — already common in some epidemiological models of illnesses such as the livestock disease foot-and-mouth.”

and

“Bayesian tools are an improvement, says Tim Palmer, a climate physicist at the University of Oxford, who pioneered the use of ensemble modelling in weather forecasting.”

along with ensemble modelling, which sounds a synonym for Bayesian model averaging… (The April issue on the topic had also Bayesian aspects that were explicitely mentionned.)