JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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Global confusion: Turns out global warming doesn’t cause wandering Jet Stream “extreme weather”

It’s a flip on a flop. After all the media headlines, a new paper suggests that some climate scientists are not just wrong, they got cause and effect mixed up, and that the wandering “blocking” jet streams are not caused by warmer arctic, but may be causing the temperature changes instead.

“”The well-publicised idea that Arctic warming is leading to a wavier jet stream just does not hold up to scrutiny,” says Screen.

“With the benefit of ten more years of data and model experiments, we find no evidence of long-term changes in waviness despite on-going Arctic warming.””

The truth is that most big models loosely predicted that global warming would make the jet streams less wiggly, but from the mid 1980s the jet-stream-trend was the other way. As the Arctic warmed the “waviness of jet streams increased”. So in 2012 a few modelers came up with a post hoc rationalization of why, really, truly, actually a warmer Arctic meant that the jets streams would wander more. The media enthusiastically repeated it, though it was contentious and disagreed with most models. But oh dear, by golly, by 2015 the trend started to reverse again. Now in [...]

SSW, Sudden Stratospheric Warming hitting a record over Antarctica, Ozone hole almost gone already?

Two days ago over the Antarctic the SSW or Sudden Stratospheric Warming was still running strong up at 10 hPa or around 30 km high.

NIWA claim it may be the strongest SSW seen in the Southern Hemisphere ever (which means the last 50 years).

Temperatures in the  green circle marked in the centre were 11C, instead of minus 40 to minus 60C. As we mentioned before, this is extremely rare, and the likely implications are that sometime in the next few weeks a cold beast will hit somewhere in the Southern Hemisphere, but no one really knows where. The Australian BOM are rather bravely predicting a warmer less rainy spring for NSW and QLD. (See below).

If only we really understood the major drivers of our climate we might have predicted this more than a few weeks in advance. Perhaps it is caused by some of those solar factors that the big GCM’s completely ignore?

From Nullschool:

Stratospheric Sudden Warming, Southern Hemisphere, Antarctica.

Two years ago, same time, we see a single large polar jetstream at 10hPA and temperatures of around minus 40C in the warmest part and minus 60 elsewhere in the jetstream. These normal winds flow [...]

Rare: Sudden Stratospheric Warming in the Southern Hemisphere — cold weather coming?

Right now a very rare southern SSW (Sudden Stratospheric Warming) is taking place, possibly peaking today or this weekend over Antarctica. In the Northern Hemisphere SSW’s happen more often and in the month afterwards, wild polar blasts like the “Beast from the East” can peel off. So somewhere way up at 10hPa or 30 – 50 km, there is an area that’s warmed from -60C  to close to zero. The warming up high throws a spanner in the normal jet streams and weeks later, down at the surface, blobs of  cold air from the poles may end up wandering far from “home”.

We (as in Africa, Australia, Argentina, or New Zealand) may get bumper snow and severe frosts, or we may not. Some researchers are getting excited and are using the word “historic”.

These are rare over the Southern Hemisphere — due to Antarctica being shaped like a circular cheesecake right over the pole and surrounded by water. The geography is cleaner and simpler than at the north pole, and that generates a strong circumpolar jetstream.  The strong pattern normally stops these sudden warmings up high which occur with wandering jetstreams.

In the Southern Hemisphere there have only [...]

Is the Sun driving ozone and changing the climate?

In 2015 the hunt for clues continues…

The central mystery in climate science is the Sun. The direct energy from the 1.4 million-kilometer-wide flaming ball stays remarkably constant. The radiation pours down on us but the relentless sameness of the watts can’t be causing of the swings in temperature on Earth. Something else is going on with the Sun. For one thing, the total light energy coming off the Sun stays almost the same but the type of light changes — the spectrum shifts –  with more shorter wavelengths at one point in the cycle and longer wavelengths at the opposite part of the cycle. These have different effects. Shorter wavelengths (UV) generate ozone in the stratosphere and penetrate the ocean. Longer wavelengths don’t. But the Sun is also sending out charged particles and driving a massive fluctuating magnetic field, both of which affect Earth’s atmosphere.

But the tiny changes in total sunlight (TSI) may still be leaving us clues about other things going on with the Sun. David Evans’ notch-delay theory is that TSI is a leading indicator, and after solar TSI peaks, the temperatures on Earth follows with a peak roughly 11 years or so later (or one [...]

Be afraid! Trapped atmospheric waves on the rise. Extreme heatwaves to come.

There are waves piling on waves in the weather.

A new press release tells us that there have been an “exceptional” number of weather extremes in summer.

Weather extremes in the summer — such as the record heat wave in the United States that hit corn farmers and worsened wildfires in 2012 — have reached an exceptional number in the last ten years. Human-made global warming can explain a gradual increase in periods of severe heat, but the observed change in the magnitude and duration of some events is not so easily explained.

Heatwaves lend themselves to headlines. Not only are they scary, but for climate researchers at a loose end, there are 1,000 flavors of wave to comb through. Is that a 3 day, 4 day or 7 day wave you are interested in? Is the cut-off 40C, 38C, 35C or a flexible percentile anomaly above the monthly average? Is it a statewide average, a national record, or a hot week in Houston? Shall we analyze that in seasons, by months, years, or part thereof? The combinations and permutations can keep a supercomputer up late at night. There’s a whole field of cherry trees ripe for the plucking.

It [...]

The North Atlantic jet stream correlates with Solar output over a millennium

A new paper (Moffa-Sánchez et al) reports that they looked at layers of dead plankton in ocean mud (otherwise known as foraminifera in marine sediments) and have reconstructed the temperature and salinity of a couple of spots in the North Atlantic between 818AD – 1780 with data on δ18O and the Mg/Ca ratios. One immediate thought, an aside, is that if this technique works, there is no shortage of ocean mud, surely, and perhaps we could drill and analyze more mud for solar correlations in other places. (I hear foraminifera live in the Southern Hemisphere too). Perhaps no one is looking for the connection with the sun?

Moffa-Sánchez et al find the big climate shifts (the 100-year variations) correlate with total solar irradiance (TSI). See especially that orange line black line track in the d graph below. I stress, correlations don’t mean causation and the mechanism is mere speculation. But I find the graph intruiging. There are a lot of turning points, and in pure “curve fitting” type of analysis, this is a better curve fit than the one with CO2. (Find me a turning point that matches with carbon dioxide!) I suspect we’ll be referring back to this paper, and I [...]

Paper suggests solar magnetic influence on Earth’s atmospheric pressure

 “…the role of the Sun is one of the largest unknowns in the climate system”

Meteorologists are already aware that changes in the interplanetary magnetic field (IMF) can affect the polar regions of Earth. Now, for the first time Lam et al report the magnetic field appears to influence atmospheric pressure in the mid latitudes. Lam compared the average surface pressure at times when the magnetic field is either very strong or very weak and found a statistically significant wave structure similar to an atmospheric Rossby wave. They claim to show that this works through a mechanism that is a conventional meteorological process, and that the effect is large enough to influence weather patterns in the mid-latitudes. The size of the effect is similar to “initial analysis uncertainties” in “ensemble numerical weather prediction” (which I take to mean “climate models”).

They are suggesting that small changes in this solar influence on the upper atmosphere could produce important changes through  “non-linear evolution of atmospheric dynamics”.

Jo suggests that IPCC-favoured climate models don’t include any solar magnetic effect at all, which is just one of many reasons why they don’t work.

The large scale wandering convolutions of the jet stream [...]