Could Pacific Northwest heatwave, European floods have been caused by the Sun?

Posted: July 29, 2021 by oldbrew in Natural Variation, Uncertainty, weather
Tags: , , ,

Credit: The Weather Network

Of course they could have been. The question is, were they? Assigning weather events to ‘global warming’ is ambiguous without a full definition of what the assigner means by that term. Jet stream blocking events discussed below are well-known to meteorologists, and constantly claiming them as evidence of a new human-caused problem with the climate is a stretch, to say the least.
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The recent record-shattering heat wave in the Pacific northwest and devastating floods in western Europe have both been ascribed to global warming by many climate scientists, says Science Under Attack.

But an alternative explanation, voiced by some climatologists yet ignored by the mainstream media, is that the disasters were caused by the phenomenon of jet-stream blocking – which may or may not be a result of global warming, and could instead arise from a weakening of the sun’s output.

Blocking refers to the locking in place for several days or weeks of the jet stream, a narrow, high-altitude air current that flows rapidly from west to east in each hemisphere and governs much of our weather.

One of the more common blocking patterns is known as an “omega block,” a buckling of the jet stream named for its resemblance to the upper-case Greek letter omega, that produces alternating, stationary highs and lows in pressure as shown in the figure below. Under normal weather conditions, highs and lows move on quickly.

According to the blocking explanation, the torrential rains that hovered over parts of western Germany, Belgium and the Netherlands came from a low-pressure system trapped between two blocking highs to the west and east – the opposite situation to that shown in the figure.

Precipitation tends to increase in a warmer world because of enhanced evap­oration from tropical oceans, resulting in more water vapor in the atmosphere. So with a blocking low stuck over the Rhine valley and the ground already saturated from previous rainfall, it’s not surprising that swollen rivers overflowed and engulfed whole villages.

A similar argument can be invoked to explain the intense “heat dome” that parked itself over British Columbia, Washington and Oregon for five blisteringly hot days last month. In this case, it was a region of high pressure that was pinned in place by lows on either side, with the sweltering heat intensified by the effects of La Niña on North America.

Several Pacific northwest cities experienced temperatures a full 5 degrees Celsius (9 degrees Fahrenheit) above previous records.

There’s little doubt that both of these calamitous events resulted from jet-stream omega blocks. Blocking can also induce cold extremes, such as the deep freeze endured by Texas earlier this year. But how can blocking be caused by the sun?

Over the 11-year solar cycle, the sun’s heat and visible light fluctuate, as does its production of invisible UV, which varies much more than the tenth of a percent change in total solar output. It’s thought that changes in solar UV irradiance cause wind shifts in the stratosphere (the layer of the atmosphere above the troposphere), which in turn induce blocking in the tropospheric jet stream via a feedback effect.

Blocking can also stem from other mechanisms. In the North Atlantic at least, a 2008 research paper found that during periods of low solar activity, blocking events in more eastward locations are longer and more intense than during higher solar activity.

Right now we’re entering a stretch of diminished solar output, signified by a falloff in the average monthly number of sunspots as depicted in the next figure.

The decline in the maximum number of sunspots over the last few cycles likely heralds the onset of a grand solar minimum, which could usher in a period of global cooling.

Full article here.

  1. Gamecock says:

    Naval-gazing. It’s just weather.

    It’s necessary in today’s science politics to provide a counter, but, otherwise, it’s just silly.

  2. pochas94 says:

    To really control people you must feed them a continuous stream of lies and have the means to enforce “belief.”

  3. erl happ says:

    Currently, La Nina is intensifying. High latitudes in both hemisphere are much cooler as of the last two years, in fact back to 1948-2021 average. Extratropical lows are at 100 year intensity lowering surface pressure in high latitudes intensifying the flow of rivers of moisture from the tropics. Luck of the draw where that moisture precipitates but the Asian Monsoons are early and hard. Warm moist air will deliver precipitation when it gets cold. Yes, it looks like 100 year weather intensity. Its instructive to look at Null school images for surface pressure and wind flow for this day in previous years. Bear in mind that the cooling trend started in 2017.

    I reckon low solar activity yields a steady solar wind that is effective in twisting the atmosphere at the poles when its most ionized due to the impact of cosmic rays on the one hand and the reduced intensity of UVB and UVC that splits the ozone molecule apart. That intensifies the extratropical lows which in turn intensifies the mid latitude highs. Both are so extensive at the moment that they have migrated into each others space. Tropical air is drawn through between the pressure systems. Wind intensity severe, especially in the Western Pacific.

  4. Jamie Spry says:

    Reblogged this on Climatism and commented:
    Jet-stream blocking, as a result of weakening of the sun’s output, appears plausible, and certainly consistent with the current-and-rapid (~2 year) cooling cycle of the global atmosphere, despite record and rising CO₂ ’emissions’.

    Just don’t mention “the sun” – one might just as easily be cancelled, or labelled a “climate denier” … all under the guise of ‘science’ and scientific discovery, of course.

  5. tallbloke says:

    Thanks Erl for the interesting comment.
    Plenty of older papers in the literature confirm the Sun as the likely cause of loopy jet stream behaviour leading to blocking patterns.

  6. oldbrew says:

    Bloomberg’s version of recent events, poses questions but hedges on the answers. Enter M. Mann…

    Heat, Floods, Fires: Jet Stream Is Key Link in Climate Disasters

    Deadly weather as far apart as China, Germany and the U.S. reveals the devastating impact of a swinging jet stream.

    The situation in the atmosphere may have been brought on by jet stream weakening, “but it will require additional analysis to confirm,” said Michael Mann, an atmospheric science professor at Pennsylvania State University. “What is certainly true is that a slower summer jet stream, which is a robust prediction of a warming climate, allows these systems to persist in the same location for longer periods of time, contributing to many of these record rainfall totals we’re seeing in Europe and Eurasia,” he said.

    The question for scientists is to what extent climate change affected those disturbances in the jet stream. It takes time to do that kind of analysis. A rapid attribution study of the Europe floods has already begun, led by the German weather service, with results expected by mid-August.

    ‘A rapid attribution study ‘ – guess what that will say 🙄
    – – –
    Blaming a wiggly jet stream on climate change? Not so fast

    The hypothesis is easy to understand, but it’s far from a consensus.
    SCOTT K. JOHNSON – 2/22/2021

    A 2017 study, for one example, concluded that trends in the stratospheric polar vortex were likely to be the result of natural variability rather than human-caused sea ice loss. And an article published in the journal Nature Climate Change last November noted that observations and studies in the last few years haven’t strengthened the case. “The short-term tendencies from the late 1980s through to early 2010s that fueled the initial speculation of Arctic influence have not continued over the past decade,” the authors wrote. “Long-term trends in the Arctic Oscillation and [jet stream] waviness, updated to winter 2019/20, are small and indistinguishable from internal variability.”

    ‘indistinguishable from internal variability’ – if it walks like a duck and quacks like a duck…

  7. JB says:

    “The recent record-shattering heat wave in the Pacific northwest and devastating floods in western Europe have both been ascribed to global warming by many climate scientists, says Science Under Attack.”

    “Because many of the dominant theories of our time do not follow the rules of science, they should more properly be labeled pseudoscience. The people who tend to believe more in theories than in the scientific method of testing theories, and who ignore the evidence against the theories they believe in, should be considered pseudoscientists and not true scientists. To the extent that the professed beliefs are based on the desire for status, wealth, or political reasons, these people are scientific prostitutes.” The Farce of Physics DB Larson

  8. oldbrew says:

    The Chill of Solar Minimum

    The sun is entering one of the deepest Solar Minima of the Space Age. Sunspots have been absent for most of 2018, and the sun’s ultraviolet output has sharply dropped. New research shows that Earth’s upper atmosphere is responding.
    . . .
    When the thermosphere cools, it shrinks, literally decreasing the radius of Earth’s atmosphere.
    – – –
    If the Earth’s atmosphere shrinks, that could have an effect on the jet stream.

    That was also proposed here:
    Essay: Solar cycle wave frequency linked to jet stream changes

    NASA says, as we enter the solar minimum, our wispy atmosphere shrinks. NASA has learned to juggle satellites that drop into lower orbits during the solar cycle. Lower down in our atmosphere the sun drives our winds and the most important winds of all, that rule all the others, are the jet streams that power around the planet at well over 160 kilometres an hour.

    When the atmosphere contracts, the jets start to meander. The meandering happens because there is a space problem; the same jet stream is jammed into less volume within a shrunken atmosphere; hence the jet streams kink. The cloud levels are slightly but measurably lower as well.

    [NOTE: I don’t necessarily agree with this article, but thought it was worth discussing – Anthony (Watts)]

  9. oldbrew says:

    Climate Scientist Warns ‘Next 20-30 Years Will Be Cold’

    Climate scientist Dr. Willie Soon has urged his fellow academics to pay closer attention to the sun’s activity, which suggests several decades of global cooling rather than warming.

    Speaking this week with Alex Newman of the New American, Soon, a Malaysian astrophysicist and aerospace engineer, said that “what we predict is that the next 20-30 years will be cold. It will be cold, so it will be a very interesting thing for the IPCC to confront.”

    The sun is in a “weakened state” and far less active than during the 1980s and 1990s, Soon noted, which should last until “around 2050.”

    “The whole climate system is powered 99.1 percent by the sun’s energy,” he stated.

    Soon, a researcher at the Solar and Stellar Physics Division of the Harvard–Smithsonian Center for Astrophysics, said that global cooling is a far greater source of concern than global warming.
    – – –
    ‘urged his fellow academics to pay closer attention to the sun’s activity’
    – but demonising CO2, or pretending to, is usually better for job security 🤨

  10. erl happ says:

    A wiggly jet stream is where low and high pressure cells occupy the same band of latitude. It comes about when the lows get deeper and wider, moving into the latitudes of the highs and the highs have to occupy the space between the lows. Simple stuff. To explain it you have to realize that the lows generate the uplift and the highs have to adapt to that.

    This is a modification of the annular modes concept or in the old days it was called the Arctic Oscillation. But if you want to see it in extremis look at the southern hemisphere here:,-81.46,436/loc=-173.829,68.587

    The Antarctic trough has deepened in recent years. With solar minimum.

    Essence of the problem is to explain the deepening of the Polar Lows, also called the extratropical lows. There are generated at jet stream level and propagate to the surface. Big ones do. Little ones don’t. At Jet stream level there is a steep density gradient between very cold air descending from the mesosphere and warm, ozone rich air, warmed by the Earths infrared that is available 25/7/365 coming in from lower latitudes. Product is uplift to the 1hPa level. What goes up must come down. It comes down in the highs. Normally in the mid latitudes with the lows pole-wards, when the lows enlarge, the highs have to fit between them. Hence wavy jet stream.

    Bear in mind that a map of total column ozone is also a map of surface pressure. Its the upper half of the column that’s rarified due to ozone heating. That’s what deBort discovered with his balloons in 1890s and Dobson confirmed from the 1930s onward. Its the stratosphere that makes the weather, not the troposphere.

    When Sir F.Wit. took over from Dobson at Oxford he stopped the investigation of the relationship between geomagnetic activity and the Arctic Oscillation and went on to chair the climate working group at the UN and picked up a Nobel with Al Gore. Dobson retired to his garden shed and made his instrument for measuring total column ozone.

    So, for the northern hemisphere attention should be focused on the evolution of the strongest low pressure zone that is called the Aleutian Low. It is that which determines the pressure gradient between the Chilean High and the Maritime continent that drives the Trades and the upwelling that occurs in the region of the Galapagos. When the lows intensify globally so do the highs. Wind stress drives upwelling in the ocean globally. The cold water rises to the surface. We call it La Nina. Fishing is good. Now is the time to get out that dusty rod and reel.

  11. Phoenix44 says:

    Thankfully we understand the climate so we we can be absolutely certain what’s going to happen in 50 years time…

  12. Stephen Wilde says:

    Hi Erl.
    Good to see you commenting here since you have always had a good grip on the basic mechanics.
    I see nothing in your description that is inconsistent with my tropopause height see-saw proposal causing global cloudiness changes via wavier jets.

  13. oldbrew says:

    To sample more of Erl Happ’s informative climate analysis go here…

  14. JB says:

    Once again ( like hurricanes) we see a “perfect” example of the spiral effect inherent in Birkeland currents. Those who’ve played with the 60s spirographs will recognize the pattern immediately.

  15. oldbrew says:

    Arctic climate change may not be making winter jet stream weird after all

    New research is pouring cold water on once-hot theory

    An influential, highly publicized theory — that a warming Arctic is causing more intense winter outbreaks of cold and snow in midlatitudes — is hitting resistance from an ongoing sequence of studies, including the most comprehensive polar modeling to date.
    – – –
    Study: “Observed Statistical Connections Overestimate the Causal Effects of Arctic Sea Ice Changes on Midlatitude Winter Climate.”

    WashPo: In this study and others, Screen and Blackport suggest that the connection between Arctic sea ice loss and extreme midlatitude events is real, but not necessarily causal. Instead, they argue, a third factor — most likely large-scale changes in atmospheric circulation that may not be permanent — is probably driving both the sea ice loss and the extreme winter events.

    Could this ‘third factor’ be linked to the recent and ongoing low solar cycles by any chance?

  16. erl happ says:

    The basic problem in climate science, and its indeed a very basic problem, is an inability to differentiate between cause and effect. Its the old problem of the chicken and the egg.

    Letting the mathematicians into the act is the source of the difficulty. They see their responsibility as bringing their equations to bear. Cause and effect is ignored. Correlation is sufficient. Attribution is someone else’s problem. The guys who were concerned with attribution were pensioned off.

    In determining cause and effect one needs to have a focus on observation first and foremost.

    The modes of change are discernable in reanalysis data. It takes effort to examine what has happened at fifteen pressure levels in the atmosphere in all eighteen 10°latitude bands from pole to pole.

    We now have 74 years of reliable data. Its necessarily based on interpolation from sparse sampling but simple physical principles that are well understood govern the behaviour of gases.

    The answers are in the data. It’s not rocket science.

    First, discard the notion that CO2 might be relevant. The Southern Hemisphere has not warmed for three decades in December and January.

    Second, discard the notion that weather and climate, the winds and the currents are driven by the energy that is acquired in the tropics.

    Throw out fluid dynamics.

    The climate system is energized by what is described as ‘extratropical cyclones’. The name in itself is discouragement, because it leads people to believe that the tropical cyclone is the more important phenomenon. Better to call it a ‘polar cyclone’,. Wind intensity is the same as for a tropical cyclone but the area affected is 100 times as large. It’s genesis is not at the surface but at jet stream levels. If he were alive today, Bjerknes would improve his analysis of polar front phenomena because he would have access to Reanalysis data. He would also improve his description of ENSO.

    These polar lows tend to aggregate and become more severe at solar minimum. The most severe solar minimum is possibly seen on 200 year time scales.

    Observe that the atmosphere moves in the same direction as the Earth, but faster, and fastest at the winter pole. The solar wind is least disturbed and most consistent in its magnetic signature at solar minimum. It’s impact on the atmosphere depends on electromagnetic phenomena. The atmosphere will be more reactive when it is most ionized, more particles orienting themselves according to the magnetic field because and behaving like little magnets zipping along the lines of magnetic force and bumping the neutrals along with them. The atmosphere is most ionized at solar minimum because cosmic rays impacting the atmosphere are most intense when sunspot activity is least. Add to that the fact that UVB and UVC is least intense at solar minimum, the atmosphere is least inflated, more dense in neutrals where it is most ionized. Ozone is not neutral and it is least affected by short wave radiation at solar minimum. It is a superb absorber of the Earths long wave radiation that is available 24/7/365 and its partial pressure is greatest in the winter hemisphere. The ability of ozone to impart kinetic energy to nitrogen and oxygen is a function of the density of the atmosphere. At least two thirds of the depth of the atmospheric column at 50-70° of latitude, the most elevated two thirds of the column, has sufficient ozone to affect its temperature and density in winter. So, in these latitudes a map of total column ozone is also a map of surface pressure.

    The polar cyclone originates where the air density gradient is steepest. That’s where subtropical air is confronted by very cold air descending over the Antarctic continent to jet stream altitudes and below according to the flux in surface pressure over the continent that hits its maximum in winter.

    Polar cyclones involve the entirely of the atmospheric column. There is no troposphere in high latitudes in winter. The elevation of ozone in little spirals of disturbed air is observable at 10 hPa over the Arctic even in the height of summer. See nullschool. What goes up must come down. When it descends into the upper half of the troposphere in the mid latitudes it drives the comings and goings of ice cloud, the stuff that is ‘stratified’, indicating the direction of flow of the upper air.

    As polar cyclones intensify in high latitudes atmospheric mass is shifted from their zone of activity to essentially reactive centers of descending air (non initiating) that develop over the oceans where the cold surface favours descent.

    The Aleutian Low doesn’t develop particularly low surface pressures but it exhibits the widest fluctuation in surface pressure. It shifts to the stratosphere in summer and there is little to show for its activity in surface pressure data until conditions favour its genesis, like now for instance, August 2021. It fluctuates so much that it impacts the pressure regime in the Antarctic trough and over the Antarctic continent. Its evolution governs the pressure differential across the Pacific Ocean, the trade winds and upwelling phenomena that are the essence of ENSO. It does that by shifting atmospheric mass towards the southern hemisphere in a heroic fashion between September and March.

  17. oldbrew says:

    The next year or two of solar cycle 25 should be interesting. If it doesn’t burst into life soon it may not do much at all.