127 citations · 842 across the 19 of their papers we have counts for
4 papers · 1 filter
Warming the early Earth - CO2 reconsidered
P. von Paris, H. Rauer, L. Grenfell +5
Despite a fainter Sun, the surface of the early Earth was mostly ice-free. Proposed solutions to this so-called "faint young Sun problem" have usually involved higher amounts of gr…
Biomarker Response to Galactic Cosmic Ray-Induced NOx and the Methane Greenhouse Effect in the Atmosphere of an Earthlike Planet Orbiting an M-Dwarf Star
John Lee Grenfell, Jean-Mathias Griessmeier, Beate Patzer +6
Planets orbiting in the habitable zone (HZ) of M-Dwarf stars are subject to high levels of galactic cosmic rays (GCRs) which produce nitrogen oxides in earthlike atmospheres. We in…
The Response of Atmospheric Chemistry on Earthlike Planets around F, G and K Stars to Small Variations in Orbital Distance
John Lee Grenfell, Barbara Stracke, Philip von Paris +4
One of the prime goals of future investigations of extrasolar planets is to search for life as we know it. The Earth's biosphere is adapted to current conditions. How would the atm…
Potential of Ozone Formation by the Smog Mechanism to shield the surface of the Early Earth from UV radiation?
John Lee Grenfell, Barbara Stracke, Beate Patzer +2
We propose that the photochemical smog mechanism produced substantial ozone (O3) in the troposphere during the Proterozoic, which contributed to ultraviolet (UV) radiation shieldin…