Abstrakt
The high-energy-density synthesis of N(x)O(y) species is simulated in gas mixtures representing an O(2)-free early-Earth atmosphere by terawatt-kilojoule-class laser-induced dielectric breakdown (LIDB). These experiments differ from previous LIDB experiments due to the 100 times greater energy delivered per pulse and sensitive analysis of products by high-resolution infrared spectroscopy.
The measured yields of NO, N2O, and NO2 are 0.08-8 x 10(15), 5 x 10(12), and 0.03-7 x 10(14) molec J(-1). The high N2O yield is above the upper-limit constraint of previous tabletop LIDB experiments and the expected yield of a thermochemical freeze-out at any temperature between 2000 and 5000 K, while the NO and NO2 yields are in broad agreement with freeze-out models.
Using a one dimensional chemical model of the Hadean atmosphere and a simple model of late bombardment, we compute the source flux of N2O assuming the same high production yield as measured experimentally and find the steady-state partial pressure of N2O is insufficient to warm the climate.