Traditionally only the solar irradiance changes are considered when evaluating the solar variability effects on climate. However, the Earth is also influenced by the effects of the continuously varying solar wind, the flow of plasma and embedded magnetic field from the Sun. Earlier studies have identified significant atmospheric effects due to solar wind disturbances. The suggested mechanisms are versatile, but mostly not quantitatively tested.
The largest interplanetary disturbances, in particular the coronal mass ejections (CME) and the high-speed solar wind streams (HSS) are known to cause dramatic effects in the near-Earth space, accelerating magnetospheric (in particular, auroral and ring current) particles to higher energies and enhancing particle precipitation into the atmosphere, especially in the mesosphere-upper thermosphere (MLT) region. Moreover, magnetospheric particle precipitation maintains and produces electric currents and fields that also affect the charged and neutral atmosphere below. The solar wind dynamic pressure is suggested to affect large-scale wave activity in the atmosphere, the circulation in the stratosphere and troposphere, and the coupling between the atmospheric layers. The effects are found to depend on the nature of the interplanetary disturbance and to be very different for CMEs and HSSs.
The aim of the Team is to summarize the present level of knowledge and to critically discuss new ideas about the effects of interplanetary disturbances on the Earth’s atmosphere and climate, and the mechanisms by which these influences are transmitted from the top to the bottom of the atmosphere.
An expected output of the Team is a review paper to comprehensively and critically present and discuss the various mechanisms and effects that the charged environment has upon the neutral atmosphere and climate. One of the novelties not covered in any earlier reviews is to take into account the possibly different affects of the above mentioned two main solar wind drivers.
The core team consists of experts covering a versatile range within solar-terrestrial sciences, including heliospheric physics, observations of energetic particles and the properties of the atmosphere at different altitudes, as well as modeling of atmospheric chemistry, dynamics and climate, as well as modeling of atmospheric chemistry and climate.
We plan to have two meetings of about 10-15 experts within July 2013 to December 2014 time frame.