4. Conclusions

[62]  Thus we have considered some experimental data and model approximations of the impact of solar activity on weather and plausible mechanisms involved. As can be inferred from this review, the investigations carried out in recent years have shown that basic objections to the idea of existence of solar weather connection (see section 1 of this review) can be overruled. Indeed, a fairly careful analysis of experimental data reveals, in a number of cases, the reasons for "failures" in the observed links between variations in solar activity and some weather indices. As far as the disbalance between the power of atmospheric processes and the cosmic rays energy is concerned, the works discussed here point out at least two sources of the energy sought. These are the latent heat of vapor and ice formation and solar energy whose input rate into the lower atmosphere is controlled by variations in atmospheric transparency and cloudiness. As to the physical mechanisms, it should be admitted that, in spite of the fact that there are clear ideas about the general character of the processes in the cloud layer caused by invasion of energetic particles, there are still no quantitative characteristics of these processes, which, no doubt, greatly complicates the interpretation of experimental data.

[63]  The main results of the works discussed are that the authors have succeeded in outlining the chain of the processes responsible for the development of disturbances in the lower atmosphere caused by variations in solar activity. However, it should be emphasized that the chain itself has been outlined rather schematically. The main reason is that, in spite of numerous research efforts, the morphology of atmospheric disturbances has not been studied thoroughly enough. For instance, it is still unclear how the vertical temperature profile in the lower atmosphere varies with latitude during the disturbance and how this profile changes with volcano eruptions. It is also not clear in what way an increase in the cosmic ray flux causes an increase in the flux of solar energy penetrating into the lower atmosphere at middle latitudes. The relation between development of disturbances at high and tropic latitudes has not been studied. The list of unresolved questions could be continued. However, even this enumeration convincingly demonstrates that combined efforts of scientists all over the world are needed to solve the problem. In all probability, this will be accomplished in future.