Mysterious Activities of Our Magnificent Sun

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

With previous NSF support, the PI has constructed theoretical models of the solar chromosphere. He has identified acoustic waves as sources of the heating of non-magnetic regions, and longitudinal and transverse tube waves as sources of the heating of magnetic flux tubes; both acoustic and magnetic waves were generated in the solar convection zone. The PI's main conclusion was that the waves alone could not supply enough energy to explain all activity observed in the uppermost chromospheric layers, the solar transition region, and in the solar corona. He also constructed theoretical models of the solar wind that were based on momentum deposition by magnetic waves, and he found that a force exerted by these waves on the background medium contributed significantly to the acceleration of the solar wind. The identification of heating mechanisms operating in the solar atmosphere and the explanation of solar activity resulting from this heating are important and still unsolved problems in solar physics research. The PI proposes to attack these problems by developing a novel approach allowing him to construct models to describe the entire solar atmosphere and account for atmospheric oscillations. The proposed models will be theoretical, self-consistent, and time-dependent, and they will be constructed after comprehensive studies of wave generation and the efficiency of non-wave (reconnection) mechanisms are completed. The most challenging task will be to incorporate a reconnection heating mechanism into the models. The PI's resulting models will then be used to predict activity in the solar chromosphere, transition region, and coronal holes. By comparing these predictions with solar observational data, the PI will be able to determine the basic heating and wind acceleration mechanisms operating in different regions of the solar atmosphere. The proposed research will play an important role in ongoing efforts to understand the principal energy sources of the solar atmosphere and the basic physical processes responsible for creating the heliosphere. The PI plans a public outreach program centered on several planetarium shows devoted to the Sun, and presented to students and the general public in a new campus facility.