Just some thoughts on Cosmic rays, CO2 and clouds.
Around half the heat of the sun transferred to the earth’s surface leaves as evaporation. That latent heat cannot be lost until that water is condensed in those fluffy things in the air – which is the primary transportation mechanism for around half the solar heat hitting the earth.
Now, as that heat needs to be dissipated, and the amount of dissipation is proportional to the amount of water dissipated, whether or not it is triggered by cosmic rays really shouldn’t effect whether or not the heat is dissipated in any one volume of air that rises by convection. So more/less of an agent to trigger cloud formation shouldn’t effect how much cloud is formed by any one volume of air, but add CO2 and that does increase the rate of cooling of that air, and cosmic rays may trigger the earlier formation of clouds, with the result that any volume of air forms clouds quicker and cools quicker, thereby considerably enhancing the rate of cooling of the atmosphere … but paradoxically speeding the rate at which clouds are cleared from the sky.
<i>CO2 cooling … just as the physical properties of the CO2 molecule cause it to block IR, so those say properties cause it to emit IR … conveniently at wavelengths where other atmospheric molecules do not absorb. So, when CO2 is above the bulk of the atmosphere and particularly above the cloud layer, it is able to emit heat through the “window” where other molecules will not block it. In essence a “move heat direct to space” card.</i>
So, cosmic rays would see clouds forming earlier and CO2 would see them clearing earlier, but the net amount of cloud would be largely determined by the IR emissive cross section of the clouds and the rate of energy being delivered by evaporative-convective transport. But, as CO2 improves the rate of emission of IR, the air cools quicker and I presume the amount of clouds would be smaller … hence more warming as more sunshine gets through (oops can’t say that!!).
However, what if the cosmic rays caused “premature condensation”. What if the rays triggered cloud formation at a lower level, a level where the pressure reduction was insufficient to trigger “complete” condensation? The result would be to slow the rate of upward movement of the air, perhaps causing air to condense over a longer period of time so that instead of a sudden burst of cloud, the result would be a longer more sustained cloud which tended to block less sunshine but for longer, perhaps with a net cooling.
What about larger weather patterns? The above really is based on those fluffy summer clouds that form in clear skies and lead to promising mornings turning into cloudy afternoons. We know large scale movements of air lead to weather fronts. In effect we have air that rises in low pressure areas, falls at high pressure areas and creates frontal systems where warm moist area meets colder air.
Obviously, this system is also driven by solar energy … warming moist air, looses heat when the air condenses and then falls as dry cold air. Obviously, the amount of cloud droplets is determined by the amount of evaporation at the surface. But those weather systems hang around for days. So, the cloud potentially also hangs around for days and whereas cloud during the day prevents sunshine, cooling the earth, so increased cloud at night prevents IR loss so keeping the earth warm. Now this is a very different system, whereas the fluffy clouds on a summer day directly affect the area from whence the solar heat is obtained to produce the evaporation, the dense areas of cloud at a weather front obtain the energy from areas far away. But again some of the same effects will occur.
Cosmic rays, will tend to trigger clouds earlier, again CO2 could cause clouds to loose heat quicker — so the air which was warmed by the condensation energy of the water (the opposite of evaporative cooling).
In fact, I see a battle here: cosmic rays as triggering this condensing warming, and CO2 as acting to cool. The two mechanisms are essential in opposition in the droplet formation zone (aka clouds). Indeed, cosmic rays allow clouds to form earlier, CO2 (and other IR heat loss mechanisms) allows them to dispel earlier. (although I’m less certain as I reread it)
Now clouds that tend to form during the day and reach saturation and then disperse at night … here CO2 may be actively causing the clouds to dispel quicker. So, where you have dense cloud, which cannot be “punched through” by an increased rate of cooling by CO2 during the day, during the night when the solar energy driving the system drops, and the cloud begins to dispel, the CO2 can cause more rapid dispersal of the clouds – leading to those “cold starry nights” and hence lead to cooling.
But, argh it gets even worse … when we have multi-layer clouds. Stratospheric and tropospheric, whilst obviously CO2 cooling works to an open sky, it doesn’t work if you have stratospheric clouds (but where do they come from? Cosmic rays?).
But what happens when the moist air has to move considerable distances before it condenses. A typical cyclone is 600 miles across, the inner zone is cloudy, whilst the outer zone is the “heating zone”, so the distance between the two is around 150miles. I’m going to guess (as I can’t find a figure), that the average wind speed is 10-20mph. This means that the time for air to go from heating zone to cooling zone is around 7-15hours.
This effectively means that the cooling/heating effects of CO2 and cosmic rays would be reversed compared to the “summer days” clouds, because the heat is lost when the sun is in the opposite condition. So rather than more cloud cooling, more cloud would actually form a cloud blanket reducing heat loss. So, more cosmic rays would lead to warming and more CO2 (cloud dispersant) would lead to cooling.
All along I’ve been visualising cloud nuclei being formed in the droplet formation zone. I now realise that if suitably stable nuclei are formed, the cosmic ray production of nuclei could occur anywhere in the rising column of air … indeed anywhere in the whole air circulation pattern … indeed, the obvious way to measure nuclei production is to look at raindrops … because somewhere in each raindrop is the fingerprint of the nuclei that grew it!”