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Unforced Variations: Jan 2018

Filed under: — group @ 1 January 2018

Happy new year, and a happy new open thread.

In response to some the comments we’ve been getting about previous open threads, we are going to try separating out OT comments on mitigation/saving the planet/theories of political action from ones related to the physical climate system. This thread remains a place for climate science issues, questions, & news, but we have started a new Forced Responses thread where people can more clearly discuss mitigation issues. We realise that sometimes it can be hard to cleanly separate these conversations, but hopefully folk can try that out as a new year’s resolution!

Note we will be updating the Model/Data comparisons over the next few weeks as the various observational data sets get updated for calendar year 2017. The main surface temperature datasets will be released around Jan 18.

What did NASA know? and when did they know it?

Filed under: — gavin @ 24 December 2017

If you think you know why NASA did not report the discovery of the Antarctic polar ozone hole in 1984 before the publication of Farman et al in May 1985, you might well be wrong.

One of the most fun things in research is what happens when you try and find a reference to a commonly-known fact and slowly discover that your “fact” is not actually that factual, and that the real story is more interesting than you imagined…

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  1. J.C. Farman, B.G. Gardiner, and J.D. Shanklin, "Large losses of total ozone in Antarctica reveal seasonal ClO x /NO x interaction", Nature, vol. 315, pp. 207-210, 1985.

Fall AGU 2017

It’s that time of year again. #AGU17 is from Dec 11 to Dec 16 in New Orleans (the traditional venue in San Francisco is undergoing renovations).

As in previous years, there will be extensive live streams from “AGU On Demand” (free, but an online registration is required) of interesting sessions and the keynote lectures from prize-winners and awardees.

Some potential highlights will be Dan Rather, Baba Brinkman, and Joanna Morgan. The E-lightning sessions are already filled with posters covering many aspects of AGU science. Clara Deser, Bjorn Stevens, David Neelin, Linda Mearns and Thomas Stocker are giving some the key climate-related named lectures. The Tyndall Lecture by Jim Fleming might also be of interest.

As usual there are plenty of sessions devoted to public affairs and science communication, including one focused on the use of humour in #scicomm (on Friday at 4pm to encourage people to stay to the end I imagine), and a workshop on Tuesday (joint with the ACLU and CSLDF) on legal issues for scientist activists and advocates.

AGU is also a great place to apply for jobs, get free legal advice, mingle, and network.

A couple of us will be there – and we might find time to post on anything interesting we see. If any readers spot us, say hi!

Unforced Variations: Dec 2017

Filed under: — group @ 3 December 2017

Last open-thread of the year. Tips for new books for people to read over the holidays? Highlights of Fall AGU (Dec 11-15, New Orleans)? Requests for what should be in the end of year updates? Try to be nice.

A brief review of rainfall statistics

Filed under: — rasmus @ 21 November 2017

There have been a number of studies which show that we can expect more extreme rainfall with a global warming (e.g. Donat et al., 2016). Hence, there is a need to increase our resilience to more rainfall in the future.

We can say something about how the rainfall statistics will be affected by a global warming, even when the weather itself is unpredictable beyond a few days.

Statistics is remarkably predictable for a large number of events where each of them is completely random (welcome to thermodynamics and quantum physics).

The normal distribution has often been used to describe the statistical character of daily temperature, but it is completely unsuitable for 24-hr precipitation. Instead, the gamma distribution has been a popular choice for describing rainfall.

I wonder, however, if there is an even better way to quantify rainfall statistics.

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  1. M.G. Donat, A.L. Lowry, L.V. Alexander, P.A. O’Gorman, and N. Maher, "More extreme precipitation in the world’s dry and wet regions", Nature Climate Change, vol. 6, pp. 508-513, 2016.