Revisiting HCN formation in Earth's early atmosphere

Feng Tian; J. F. Kasting; K. Zahnle

doi:10.1016/j.epsl.2011.06.011

Revisiting HCN formation in Earth's early atmosphere

Feng Tian
, J. F. Kasting
, K. Zahnle

Research output: Contribution to journal › Article › peer-review

127 Scopus citations

Abstract

Using a new photochemical model, the HCN chemistry in Earth's early atmosphere is revisited. We find that HCN production in a CH₄-rich early atmosphere could have been efficient, similar to the results of a previous study (Zahnle, 1986). For an assumed CH₄ mixing ratio of 1000ppmv, HCN surface deposition increases from 2×10⁹cm^-2s^-1 at fCO₂=3% to more than 1×10¹⁰cm^-2s^-1 (30Tg/yr) at fCO₂=0.3% and 1%. These conditions may well have applied throughout much of the Archean eon, 3.8-2.5Ga. Prior to the origin of life and the advent of methanogens, HCN production rates would likely have been at 1×10⁷cm^-2s^-1 or lower, thereby providing a modest source of HCN for prebiotic synthesis.

Original language	English (US)
Pages (from-to)	417-423
Number of pages	7
Journal	Earth and Planetary Science Letters
Volume	308
Issue number	3-4
DOIs	https://doi.org/10.1016/j.epsl.2011.06.011
State	Published - Aug 15 2011

All Science Journal Classification (ASJC) codes

Geophysics
Geochemistry and Petrology
Earth and Planetary Sciences (miscellaneous)
Space and Planetary Science

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10.1016/j.epsl.2011.06.011

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title = "Revisiting HCN formation in Earth's early atmosphere",

abstract = "Using a new photochemical model, the HCN chemistry in Earth's early atmosphere is revisited. We find that HCN production in a CH4-rich early atmosphere could have been efficient, similar to the results of a previous study (Zahnle, 1986). For an assumed CH4 mixing ratio of 1000ppmv, HCN surface deposition increases from 2×109cm-2s-1 at fCO2=3\% to more than 1×1010cm-2s-1 (30Tg/yr) at fCO2=0.3\% and 1\%. These conditions may well have applied throughout much of the Archean eon, 3.8-2.5Ga. Prior to the origin of life and the advent of methanogens, HCN production rates would likely have been at 1×107cm-2s-1 or lower, thereby providing a modest source of HCN for prebiotic synthesis.",

author = "Feng Tian and Kasting, \{J. F.\} and K. Zahnle",

note = "Funding Information: We thank 3 anonymous reviewers for their constructive comments. F.T. thanks Dr. R.V. Yelle for helpful discussions on HCN chemistry in Titan's atmosphere and Dr. V. Veronique for help with HCN photolysis cross sections. F.T. and O.B.T. are partially supported by NASA Award\# NNX10AR17G . ",

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doi = "10.1016/j.epsl.2011.06.011",

language = "English (US)",

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journal = "Earth and Planetary Science Letters",

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TY - JOUR

T1 - Revisiting HCN formation in Earth's early atmosphere

AU - Tian, Feng

AU - Kasting, J. F.

AU - Zahnle, K.

N1 - Funding Information: We thank 3 anonymous reviewers for their constructive comments. F.T. thanks Dr. R.V. Yelle for helpful discussions on HCN chemistry in Titan's atmosphere and Dr. V. Veronique for help with HCN photolysis cross sections. F.T. and O.B.T. are partially supported by NASA Award# NNX10AR17G .

PY - 2011/8/15

Y1 - 2011/8/15

N2 - Using a new photochemical model, the HCN chemistry in Earth's early atmosphere is revisited. We find that HCN production in a CH4-rich early atmosphere could have been efficient, similar to the results of a previous study (Zahnle, 1986). For an assumed CH4 mixing ratio of 1000ppmv, HCN surface deposition increases from 2×109cm-2s-1 at fCO2=3% to more than 1×1010cm-2s-1 (30Tg/yr) at fCO2=0.3% and 1%. These conditions may well have applied throughout much of the Archean eon, 3.8-2.5Ga. Prior to the origin of life and the advent of methanogens, HCN production rates would likely have been at 1×107cm-2s-1 or lower, thereby providing a modest source of HCN for prebiotic synthesis.

AB - Using a new photochemical model, the HCN chemistry in Earth's early atmosphere is revisited. We find that HCN production in a CH4-rich early atmosphere could have been efficient, similar to the results of a previous study (Zahnle, 1986). For an assumed CH4 mixing ratio of 1000ppmv, HCN surface deposition increases from 2×109cm-2s-1 at fCO2=3% to more than 1×1010cm-2s-1 (30Tg/yr) at fCO2=0.3% and 1%. These conditions may well have applied throughout much of the Archean eon, 3.8-2.5Ga. Prior to the origin of life and the advent of methanogens, HCN production rates would likely have been at 1×107cm-2s-1 or lower, thereby providing a modest source of HCN for prebiotic synthesis.

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DO - 10.1016/j.epsl.2011.06.011

M3 - Article

AN - SCOPUS:79960557435

SN - 0012-821X

VL - 308

SP - 417

EP - 423

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

IS - 3-4

ER -

Revisiting HCN formation in Earth's early atmosphere

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