A new run of the CLOUD experiment examines the direct effect of cosmic rays on clouds

Posted: October 16, 2019 by oldbrew in Astrophysics, atmosphere, Clouds, cosmic rays, research

As this is going on, cosmic rays are near a record high since measurements began. Researchers are using natural cosmic rays this time.

CERN’s colossal complex of accelerators is in the midst of a two-year shutdown for upgrade work.

But that doesn’t mean all experiments at the Laboratory have ceased to operate.

The CLOUD experiment, for example, has just started a data run that will last until the end of November, reports Phys.org.

The CLOUD experiment studies how ions produced by high-energy particles called cosmic rays affect aerosol particles, clouds and the climate.

It uses a special cloud chamber and a beam of particles from the Proton Synchrotron to provide an artificial source of cosmic rays. For this run, however, the cosmic rays are instead natural high-energy particles from cosmic objects such as exploding stars.

“Cosmic rays, whether natural or artificial, leave a trail of ions in the chamber,” explains CLOUD spokesperson Jasper Kirkby, “but the Proton Synchrotron provides cosmic rays that can be adjusted over the full range of ionisation rates occurring in the troposphere, which comprises the lowest ten kilometres of the atmosphere. That said, we can also make progress with the steady flux of natural cosmic rays that make it into our chamber, and this is what we’re doing now.”

In its 10 years of operation, CLOUD has made several important discoveries on the vapours that form aerosol particles in the atmosphere and can seed clouds.

Although most aerosol particle formation requires sulphuric acid, CLOUD has shown that aerosols can form purely from biogenic vapours emitted by trees, and that their formation rate is enhanced by cosmic rays by up to a factor 100.

Most of CLOUD’s data runs are aerosol runs, in which aerosols form and grow inside the chamber under simulated conditions of sunlight and cosmic-ray ionisation.

The run that has just started is of the “CLOUDy” type, which studies the ice- and liquid-cloud-seeding properties of various aerosol species grown in the chamber, and direct effects of cosmic-ray ionisation on clouds.

The present run uses the most comprehensive array of instruments ever assembled for CLOUDy experiments, including several instruments dedicated to measuring the ice- and liquid-cloud-seeding properties of aerosols over the full range of tropospheric temperatures.

In addition, the CERN CLOUD team has built a novel generator of electrically charged cloud seeds to investigate the effects of charged aerosols on cloud formation and dynamics.

“Direct effects of cosmic-ray ionisation on the formation of fair-weather clouds are highly speculative and almost completely unexplored experimentally,” says Kirkby. “So this run could be the most boring we’ve ever done—or the most exciting! We won’t know until we try, but by the end of the CLOUD experiment, we want to be able to answer definitively whether cosmic rays affect clouds and the climate, and not leave any stone unturned.”


  1. Pablo says:

    Off topic, but people should read this… on the falsehood of “greenhouse gas” theory via Joe Postma’s site.

    Click to access climate-3.pdf

  2. kate gibbens says:

    Provocative link Pablo for a layman, thanks a lot!
    So alarmists are flat-earthers who want us all to go cold turkey on real climate and reject rocket science while dividing the sun’s heat by 4 and human testicles by 2!?
    (just my layman’s input on inputting output…)

  3. oldbrew says:

    Postma is correct that daytime and nighttime have to be treated differently. ‘Standard’ energy budget diagrams ignore that.

  4. It doesn't add up... says:

    Will Jasper Kirby and team be allowed to publish his findings this time?

  5. oldbrew says:

    Tiny particles lead to brighter clouds in the tropics
    October 16, 2019 , University of Colorado at Boulder

    ‘Clouds alter Earth’s radiative balance, and ultimately climate, depending on how bright they are. And the new paper describes a process that may occur over 40 percent of the Earth’s surface, which may mean today’s climate models underestimate the cooling impact of some clouds.
    . . .
    Exactly how aerosols and clouds affect radiation is a big source of uncertainty in climate models. “We want to properly represent clouds in climate models,” said Williamson. “Observations like the ones in this study will help us better constrain aerosols and clouds in our models and can direct model improvements.” ‘


    Er…just a minute – ‘a big source of uncertainty in climate models’? How many of those are there?

  6. oldbrew says:

    Physicists: CO2 Molecules Retain Heat Just 0.0001 Of A Second, Meaning CO2-Driven Warming ‘Not Possible’
    By Kenneth Richard on 17. October 2019


    Stick that on your banners, Extinction rabble 😎 – then go home.

  7. oldbrew says:

    Why are cosmic rays intensifying? The main reason is the sun. Solar storm clouds such as coronal mass ejections (CMEs) sweep aside cosmic rays when they pass by Earth. During Solar Maximum, CMEs are abundant and cosmic rays are held at bay. Now, however, the solar cycle is swinging toward Solar Minimum, allowing cosmic rays to return. Another reason could be the weakening of Earth’s magnetic field, which helps protect us from deep-space radiation.

    https://spaceweather.com/archive.php [today’s date]

  8. oldbrew says:

    OCTOBER 16, 2019
    Scientists closer to understanding nature of ultrahigh-energy cosmic rays
    – by National Research Nuclear University

    The origin of cosmic rays (high-energy protons and atomic nuclei) is one of the most important mysteries of modern science. Upon solving it, humanity may come closer to creating new sources of super-high energy. For example, space-based particle accelerators could provide billions of times more acceleration energy than the most powerful particle accelerator on Earth, the Large Hadron Collider.

    – – –
    NASA Mission Discovers Particle Accelerator in Heart of Van Allen Radiation Belts

    WASHINGTON — Using data from a NASA satellite, scientists have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, a region of super-energetic, charged particles surrounding the globe and known as the Van Allen radiation belts.

    New results from NASA’s Van Allen Probes show the acceleration energy is in the belts themselves. Local bumps of energy kick particles inside the belts to ever-faster speeds, much like a well-timed push on a moving swing. [bold added]


    In other words, resonance…

    a vibration of large amplitude in a mechanical or electrical system caused by a relatively small periodic stimulus of the same or nearly the same period as the natural vibration period of the system [bold added]


  9. David says:

    Oldbrew says “Physicists: CO2 Molecules Retain Heat Just 0.0001 Of A Second, Meaning CO2-Driven Warming ‘Not Possible’
    By Kenneth Richard on 17. October ”

    I thought the residence time increase was due to random redirection of said LWIR. ( About 50 percent back towards the surface.)

  10. oldbrew says:

    Even more saliently, Nahle determined that the rate at which CO2 molecules can retain heat at the surface may only last about 0.0001 of a second (Nahle, 2011b).

    CO2 is a tiny 0.04% of the atmosphere, and much of that has been around for a very long time already.

  11. David A says:

    Oldbrew, I see the surface level retention is equally short, although there conduction is I understand the much more common transmission of energy. At any rate the actual residence time increase of LWIR appears to he dwarfed by any change in ocean absorption due to solar flux and or cloud cover and W/V flux.

  12. Thank you for this great post! I really enjoyed reading it and learning from your thoughts! I have recently published an article on my blog about cloud seeding and it’s effectiveness. If you have time, it would be great if you could check out my article and let me know your thoughts! Thanks 🙂