| Abstrakt: |
Observations and theory relevant to evaluating the importance of the effect of Ionosphere‐Earth current density, JZ, in the global electric circuit on cloud microphysics and cloud opacity at high latitudes, with presumed consequences for surface pressure, are reviewed and updated. The day‐to‐day input variations are less than 10% of their mean values, as are the reported cloud and pressure effects, but could be indicative of more important longer‐term effects, and of neglected processes in aerosol‐cloud interactions. There is consistent evidence for responses to both externally (solar‐wind) and internally (thunderstorm and shower‐cloud) generated changes in JZ and cloud opacity. The pressure correlations show non‐stationary behavior, with changes in phase relative to that of the solar wind input and JZ variations on interdecadal timescales. These might be due to the non‐stationary nature of the solar wind, and non‐stationary aerosol populations. For modeling the cloud effects there are considerable uncertainties in the size and charge distributions of aerosol particles, droplets, and ice particles. The cloud radiative coupling with periodic solar wind inputs may nudge internal tropospheric waves into phase coherence at times when the amplitude of the solar input and the duration of the input trains exceed minimum values. Plain Language Summary: Correlations of small, day‐to‐day and decadal changes, in clouds and atmospheric dynamics with inputs from the solar wind have been reported for more than a century. We evaluate and update correlations of day‐to‐day cloud opacity and surface pressure at high latitudes with changes in the Ionosphere‐Earth current density in the global electric circuit. The current density is also affected by internal atmospheric (thunderstorm and shower cloud) generators, and similar correlations are reviewed. The consistency with a mechanism in which electrically charged aerosol particles interact with electrically charged droplets is discussed, with suggestions for work to resolve a number of outstanding issues. Key Points: Observations showing day‐to‐day correlations of clouds and surface pressure with electrical inputs from the solar wind and thunderstorms, are reviewed and updatedUncertainties in evaluating the agreement with a mechanism for electric charge effects on cloud microphysics are identifiedThe effects are small, but may be more important for decadal variations, and as a neglected process in cloud microphysics [ABSTRACT FROM AUTHOR] |
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