Affiliation:
1. Department of Physics and Astronomy University of Exeter Exeter UK
2. Met Office Exeter UK
3. NASA Goddard Space Flight Center Greenbelt MD USA
Abstract
AbstractWe present results from 3D simulations of the Archean Earth including a prescribed (non‐interactive) spherical haze generated through a 1D photochemical model. Our simulations suggest that a thin haze layer, formed when CH4/CO2 = 0.1, leads to global warming of ∼10.6 K due to the change of water vapor and cloud feedback, compared to the simulation without any haze. However, a thicker haze layer, formed when CH4/CO2 > 0.1, leads to global cooling of up to ∼65 K as the scattering and absorption of shortwave radiation from the haze reduces the radiation from reaching the planetary surface. A thermal inversion is formed with a lower tropopause as the CH4/CO2 ratio increases. The haze reaches an optical threshold thickness when CH4/CO2 ∼ 0.175 beyond which the atmospheric structure and the global surface temperature do not vary much.
Publisher
American Geophysical Union (AGU)
Subject
Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Atmospheric Science,Geophysics