[A-OS11] Continental Oceanic Mutual Interaction - Planetary Scale Material Circulation

[AOS11-01] Impact of Extreme Events on Earth and Its Implications to Early Earth

★Invited Papers

*Vladimir Airapetian^1,2, Howard Chen³, Guillaume Gronoff⁴, Meng Jin⁵, Junxiang Hu^1,6 (1.NASA Goddard Space Flight Center, 2.American University, 3.Florida Institute of Technology, 4.NASA LaRC/SSAI, 5.LMSAL, 6.University of Alabama at Huntsville)

Keywords:Early Earth, CMEs, SEPs

Our Sun sporadically produces powerful eruptive events in the form of flares and coronal mass ejections (CMEs), that can produce highly intense fluxes of solar energetic particles (SEPs), which escape into interplanetary space and interact with Earth’s atmosphere. Magnetic storms associated with CMEs and SEP events are capable of severely impacting the technological infrastructure of the modern world including human health. The XUV fluxes and magnetospheric input in the form of electron precipitation and enhanced Joule heating may also cause detrimental effects on the Earth’s upper atmosphere including variability of its neutral density and temperature as well as changes in atmospheric chemistry and the planet’s global climate. Geomagnetic disturbances also cause geomagnetically induced currents (GIC) to flow in power grids, pipelines, and railway systems. Understanding extreme solar events and their impact on Earth’s infrastructure will not only help in mitigating their harmful consequences on modern life and communication systems but will also help with understanding complex geomagnetic and atmospheric processes. While the famous Carrington event of 1859 CE is considered one of the strongest known solar storms to hit the Earth, recent detections of enhancements in ¹⁴C, ³⁶Cl, ¹⁰Be in tree rings and ice cores suggest that our Sun has produced 8 extreme events (or superflares) with energies possibly up to 10³⁴ ergs. The 774/5 CE SEP event was found to be one of the strongest in the past millennia. This suggests that the terrestrial impact of a similar eruptive event on our technologically based society could be severe. In my talk I will address the following question: What are the impacts of the 774/5 event’s XUV flux, the dynamic pressure and magnetic field of associated CME-driven shocks, and the impact of shock-accelerated particles on space weather and the chemistry of the mid and lower atmosphere, specifically ozone destruction, impact on climate? I will discuss how we can reconstruct a fast and energetic CME and (super)flare event from the SEP fluences derived from the data of cosmogenic isotopes. I will then discuss the impact of such extreme CME on the magnetosphere of our planet. This methodology has been earlier applied by our team to model extreme and frequent CME impact on the current and early Earth. Finally, I will show the results of a coupled upper/middle/lower ionization chemistry model, AEROPLANETS, with the Whole Atmosphere Community Climate Model (WACCM) that provides the response of middle and lower atmospheric chemistry on ozone destruction and global climate of Earth. I will also discuss implications of this model for the climate of Hadean Earth.