"events strongly affect ozone at 60–80 km, leading to extremely large (up to 90%) short-term ozone depletion. This impact is comparable to that of large, but much less frequent, solar proton events. On solar cycle timescales, we find that EEP causes ozone variations of up to 34% at 70–80 km. With such a magnitude, it is reasonable to suspect that EEP could be an important part of solar influence on the atmosphere and climate system."
"On solar cycle scales, we find that EEP causes significant ozone variations of up to 34% at 70–80 km. As ozone is important to atmospheric heating and cooling rates, this level of ozone variation could significantly affect the local mesospheric temperature balance6. Our results emphasize the importance of the EEP effect on mesospheric ozone and significantly improve our understanding of the impacts of the energetic particles on the atmosphere."
"Most studies have concentrated on the so-called indirect particle precipitation effect caused by the production of odd nitrogen (NOx) in the polar upper atmosphere, its subsequent transport to lower altitudes inside the wintertime polar vortex, depletion of ozone in the stratosphere and effects on the radiative balance of the middle atmosphere10, 11, 12, 13. These effects may further couple to atmospheric dynamics and propagate downwards by changing polar winds and atmospheric wave propagation through wave—mean flow interaction14, 15, 16. Several studies have suggested links between the EPP indirect effect on ozone and regional wintertime tropospheric climate variability."
"Our results show that the direct, HOx-driven effect of EEP is causing significant, previously unaccounted for, ozone variability in the mesosphere that are observable on solar cycle timescales. Although these effects from EEP-HOx have not been considered in atmospheric and climate models to date, dynamical changes in the mesosphere and stratosphere have been reported as a result of SPEs and the indirect EEP impact on ozone19, 21."
"Considering the magnitude of the direct ozone effect, tens of percent in wintertime polar regions, it is reasonable to suspect that EEP could be an important contributor to the Sun-climate connection on solar cycle timescales. For comparison, the 11-year variability in UV radiation has a less than 10% effect on annual mean mesospheric ozone at mid-to-low latitude22, 23, 24. Thus, more research should be directed towards better understanding the potential further effects from EEP and its role in the overall Solar influence on climate. Currently, in most high-top climate models the solar input does not include EEP and it is completely missing from low-top models."Ozone is the 3rd most influential greenhouse gas in the atmosphere, after water vapor and CO2, as illustrated by the large cooling effects upon the stratosphere in this illustration:
3. Stratospheric cooling rates: The picture shows how water, cabon dioxide and ozone contribute to longwave cooling in the stratosphere. Colours from blue through red, yellow and to green show increasing cooling, grey areas show warming of the stratosphere. The tropopause is shown as dotted line (the troposphere below and the stratosphere above). For CO2 it is obvious that there is no cooling in the troposphere [or warming!], but a strong cooling effect in the stratosphere. Ozone, on the other hand, cools the upper stratosphere but warms the lower stratosphere. Figure from: Clough and Iacono, JGR, 1995; adapted from the SPARC Website. Please click to enlarge! (60 K) [Source] [Rebuttal] [Ozone O3 is shown as a cooling agent in the upper stratosphere, but a warming agent in the upper troposphere to lower stratosphere]
In addition to the large effects on ozone as a potential solar amplification mechanism, this paper begs the question how much of the alleged ozone hole over Antarctica is related to solar activity vs. man-made CFCs? As this paper notes, these solar effects on ozone are most pronounced over the poles where the Antarctic ozone hole is located. In addition, the wide variations in the Antarctic ozone hole from year to year indicate solar activity is more likely responsible rather than a continuous effect from CFCs. Is this why no significant trend in the ozone hole has been found now 30 years after the Montreal Protocol to outlaw CFCs?
Excerpts from full paper: