jet stream – Hot Topic

Any way the wind blows: earth’s atmosphere animated

This is just brilliant: click on the image to see an animation of atmospheric flows around the planet, coded by Cameron Beccario, using forecast data from NOAA¹. It’s mesmerising and addictive, but educational and informative too. Click on the “earth” on the bottom left of the web page, and a menu pops up that allows you to choose different layers of the atmosphere (explained on the about page). Click on 250mb to see the jet streams that guide storm tracks. This is what they looked like over New Zealand yesterday (the brighter the colour, the faster the winds).

NZwindsjetstreams

If you click and drag the globe, you can choose your viewpoint and zoom in or out. Here are the jet stream tracks above the northern hemisphere yesterday:

NHwindsjetstream

You can also play with different map projections – the row of letters in the menu – go backwards and forwards through forecasts, and click to hover above your location (the circle in brackets). Beccario was inspired by the hint.fm wind map of North America, and cut his teeth by coding a wind map for Tokyo. Wonderful stuff.

[Bo Rap with lyrics]

Data updates every three hours [↩]

Where the wind blows, it rains: Arctic warming and wacky jetstream ruins European summers

The dramatic loss of summer sea ice in the Arctic has prompted a lot of research interest in the way that this is affecting weather patterns around the northern hemisphere. The latest contribution is Influence of Arctic sea ice on European summer precipitation, by Dr James Screen of the University of Exeter [PhysOrg]. In this “video abstract”, he explains how reductions in Arctic sea ice affect the position of jetstream — the ribbon of winds winding around the planet that guides weather systems — bringing more summer storms to Western Europe, and a recent run of record-setting wet summers to the UK. But as he points out, the effects are planet-wide:

The impacts are not just over northwest Europe. Actually in the model, what we find is that whilst the sea ice loss increases rainfall over northwest Europe, we actually find drier conditions over Mediterranean Europe. Also the jet steam shifts over North America, which can have implications for the weather there too.

Dr Screen’s study underlines a point that I have been making for some time: rapid climate change is not something theoretical that will happen in the future — it’s happening now and we’re feeling the effects. Warming in the Arctic is driving sea ice loss, and the atmospheric consequences are changing the shape of the weather right round the northern half of the planet.

Also interesting, and also looking at jetstream patterns is Probability of US heat waves affected by a subseasonal planetary wave pattern, in which the authors find that US heatwaves might be predictable 15-20 days earlier than at present by monitoring a particular jetstream wave pattern. [Science Daily]

It’s worth noting that an especially vigorous jetstream directed and helped to intensify the recent huge European storm that hammered the UK, Germany and Denmark, killing 16 people and causing huge amounts of damage. Christopher Burt at WeatherUnderground provides a handy overview of the storm that has four names — St Jude, Christian, Simone and Carmen. The storm centre moved 2,000 km in 26 hours, a remarkable pace of 77 kph.

Planet waves, and the big heat

[youtube https://www.youtube.com/watch?v=tY0RdXmLGdU&w=480]

It’s certainly hot in the southwestern USA at the moment — a dome of heat has established itself under a persistent high pressure ridge, and temperatures are pushing up towards all-time highs. Wildfires are running out of control. One caused the tragic death of 19 firefighters at Yarnell Hill in Arizona yesterday. One more extreme weather event to add to this year’s growing list, and as with most of the others, there’s a clear sign of a link with rapid climate change. That heat dome is being held in place by a large, slow-moving northward loop in the jetstream — and that jetstream pattern is beginning to look very much like the characteristic fingerprint of rapid warming in the northern hemisphere, as Jennifer Francis explains in this video, recorded at a Climate Desk event in Washington last month. It’s just about the clearest explanation of what’s going on that I’ve encountered — particularly in her description of why the jetstream exists in the first place, and why warming is changing the way it behaves. If you want to understand what’s going on, you have to watch this.

There’s a full recording of the Climate Desk event here, including a talk by Weather Channel meteorologist Stu Ostro. Ostro used to be a confirmed sceptic, but began to see changes in weather patterns that he traced back to the effects of warming — specifically, an increase in the “thickness” of the atmosphere, the very thing that’s driving the changes in jetstream behaviour.

Sensitivity and consensus; theory and practice

So Cook et al¹ confirms that there really is a consensus in climate science: 97% of the peer-reviewed literature over the last 20 years supports the fact that humans are responsible for the warming. It’s a solid result, confirming the earlier work of Oreskes and others, but its importance lies in the fact that public perceptions of that consensus lag behind reality. As John puts it:

Quite possibly the most important thing to communicate about climate change is that there is a 97% consensus amongst the scientific experts and scientific research that humans are causing global warming. Let’s spread the word and close the consensus gap.

Indeed. Count this as my small contribution. Meanwhile, another recent paper very nicely demonstrates that the existence of a consensus on the basic facts of warming does not mean that scientists have to agree about everything. Continue reading “Sensitivity and consensus; theory and practice”

Yes, that Cook — the one from Skeptical Science and The Climate Show. Quantifying the consensus on anthropogenic global warming in the scientific literature, John Cook et al 2013 Environ. Res. Lett. 8 024024
doi:10.1088/1748-9326/8/2/024024 [↩]

TDB today: Watching the ice melt

My column at The Daily Blog this week is all about ice — specifically the start of the melt season in the Arctic, and what that means for the climate of the northern hemisphere.

What’s going on in the Arctic is rapid climate change, and it’s happening now. It’s changing the weather that most of the world experiences. It’s the most important and most visible of the multitude of climate impacts we’re forcing on the planet, and it’s worth watching every day. Will this year set a new record summer low for sea ice? It’s too early to call, but one thing is certain. Northern hemisphere climate has already changed, and will continue to change in ways we’re only beginning to fathom.

The continuing Arctic melt gives the lie to the “no warming since (pick a date)” meme being pushed by the usual suspects. In fact it does more than show Monckton and his sad supporters to be wrong — it shows them to be burying their heads so far into the septic sand that their arses are disappearing. I shall be returning to this theme as the Arctic summer progresses…