Robert sent in the link to www.sciencealert.com/natural-radio-emission-has-been-discovered-in-the-a… … in July of 2020 the Parker solar probe swooped low around Venus and discovered something odd. At 517 miles above the Venusian surface it recorded a low frequency radio signal. This suggest the probe had skimmed through the top of the ionosphere.
There are some lessons to be learned, we might think, which may equally apply to the Earth. Worth noting. The Parker solar probe uses Venus for gravity assist in order to sling the probe into a different trajectory and change its velocity. There was a familiar ring to the radio noise as the same had been observed on another mission, recorded by the Galileo probe when it skimmed the ionosphere of Jupiter's moons. In the ionosphere solar radiation from the Sun is ionised resulting in a charged plasma that produces low frequencies radio emissions.
It seems the ionosphere of Venus shrink during solar minimum = low solar activity. This occurs at the end of 11 year solar cycles, as opposed to widening at solar maximum = the mid point of 11 year solar cycles. This is where the analogy with the earth is interesting as it implies the same must be true. The ionosphere expands during mid solar cycle and shrinks towards the end of the solar cycle. On top of that we have prolonged solar minimums – periods of low solar activity over a long period. This was one of the features of the Little Ice Age, the Maunder minimum for example. The implication is that in the 16th and 17th centuries the ionosphere may have shrunk and may explain the many reports of enhanced meteoric activity and other atmospheric events, usually passed off as superstition by our illustrious historical talking heads. Let us take an example. The 2013 Chelyabinsk meteor exploded in the upper atmosphere in mid term of an 11 year solar cycle – when the ionosphere was at its most swollen. The explosion was too high to cause damage on the surface of the earth – although superficial damage to buildings, especially windows, was reported by the Russian authorities. If the meteor had arrived 5 years later the ionosphere would have been smaller – and the meteor may have exploded at a lower altitude [causing structural damage to buildings] etc. However, when it comes to the annual meteor stream encounters, such as the Geminids, these too would have been burning up much lower in the atmosphere, back in the Little Ice Age. One may wonder if this kind of phenomenon sparked a latent memory of past events and led to such things as religious conflict and mass hysteria, even the witch hunts.
See also https://phys.org/news/2021-05-parker-natural-radio-emission-venus.html …
Robert also sent in another link vaguely connected to the above – www.sciencealert.com/study-shows-how-lightning-actually-helps-earth-s-at… … Robert compares what occurs on earth, via lightning, to what has been observed to happen on Mars – see for example www.futurity.org/mars-dust-storms-perchlorate-1898402-2/ … and comments, 'it appears that electric discharge plays an important role in the atmosphere and surface electrochemical processes on planets within our solar system'. That is an astute appraisal of the evidence. It is well known that lightning bolts scrub the air by creating nitric oxide and hydroxide to flush out various greenhouse gases. Lightning, in general, and not just the dramatic bolts that strike buildings and trees, or the occasional hapless human and animal victim, is unfriendly to methane for example, and carbon monoxide in the atmosphere. Lightning produces high levels of oxidants such as hydroxyl and hydroperoxyl radicals. These observed reactions are taking place mostly in the clouds – although lightning bolts can reach the surface. The piece goes on to tell us that global warming will mean more thunderstorms and lightning which will impact the greenhouse gases in the atmosphere, without mentioning the frequency of thunderstorms and lightning in current tropical regions. Are they supposing the tropical region is going to expand at the expense of the temperate zone? Is that at all possible? At the same time it is worth noting that lightning's effect on co2 is glaringly omitted from the scare mongering. If it can severely deplete methane and then why not co2?