Details

Autor(en) / Beteiligte

• Na, MD
• Navarro-Gonzalez, R
• Raulin, F
• Coll, P
• McKay, C P
• Schwartz, AW

Titel

Atmospheric nitrogen fixation rate by lightning and coronae discharges over the earth's geologic history

Ist Teil von

• Origins of life and evolution of biospheres, 2002-12, Vol.32 (5-6), p.408-408

Erscheinungsjahr

2002

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The production of reactive nitrogen species in the troposphere by lightning and coronae discharges is the only natural source of fixed nitrogen to the biosphere today. In the early Earth, abiotic nitrogen fixation was a fundamental prerequisite for the origin and sustainability of life until the advent of biological nitrogen fixation. Reactive nitrogen could have been delivered to the early Earth by exogenous contributions or fixed by endogenous sources. It is predicted that the endogenous sources dominated the supply of nitrogenated compounds. Among these sources, electrical discharges during thunderstorm could have been an important source of reactive nitrogen (NO, NO sub(2), and N sub(2)O) in the terrestrial troposphere. Here we report the first experimental study of the variation of the atmospheric nitrogen fixation rate by cloud-to-ground lightning and by point discharges in the ground over the whole Earth's geologic history. The energy yields of nitric oxide, nitrous oxide and nitrogen dioxide were estimated over a wide range of atmospheric compositions, from neutral (CO sub(2) - N sub(2)) to oxidized conditions (O sub(2) - N sub(2)). In the absence of free oxygen, NO was identified as the sole N-product formed during lightning whereas during coronae processes N sub(2)O was produced as a secondary product. In the presence of molecular oxygen, among the nitrogen oxides produced NO sub(2) was the predominant form.