Title: Measuring and modeling the lifetime of nitrous oxide including its variability: NITROUS OXIDE AND ITS CHANGING LIFETIME

Abstract

The lifetime of nitrous oxide, the third-most-important human-emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross-section data for ozone and molecular oxygen plus kinetics for O(¹D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly-to-biennial variations in lifetime and tropical abundance are well matched by four independent chemistry-transport models driven by reanalysis meteorological fields for the period of observation (2005–2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry-climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N₂O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human-natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.

Authors:

Prather, Michael J. ^[1]; Hsu, Juno ^[1]; DeLuca, Nicole M. ^[1]; Jackman, Charles H. ^[2]; Oman, Luke D. ^[2]; Douglass, Anne R. ^[2]; Fleming, Eric L. ^[3]; Strahan, Susan E. ^[4]; Steenrod, Stephen D. ^[5]; Søvde, O. Amund ^[6]; Isaksen, Ivar S. A. ^[7]; Froidevaux, Lucien ^[8]; Funke, Bernd ^[9]

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+ Show Author Affiliations

1. Earth System Science, University of California Irvine, Irvine California USA
2. NASA Goddard Space Flight Center, Greenbelt Maryland USA
3. NASA Goddard Space Flight Center, Greenbelt Maryland USA, Science Systems and Applications, Inc., Lanham Maryland USA
4. Science Systems and Applications, Inc., Lanham Maryland USA
5. NASA Goddard Space Flight Center, Greenbelt Maryland USA, Goddard Earth Sciences Technology and Research Center, Universities Space Research Association, Columbia Maryland USA
6. Center for International Climate and Environmental Research-Oslo, Oslo Norway
7. Department of Geosciences, University of Oslo, Oslo Norway
8. Jet Propulsion Laboratory, Pasadena California USA
9. Instituto de Astrofísica de Andalucía, CSIC, Granada Spain

Publication Date:

Fri Jun 05 00:00:00 EDT 2015

Research Org.:

Univ. of California, Irvine, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1225771

Alternate Identifier(s):

OSTI ID: 1454734

Grant/Contract Number:  

SC0007021; AYA2011-23552; 1005042; SC0012536

Resource Type:

Published Article

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Volume: 120; Journal Issue: 11; Journal ID: ISSN 2169-897X

Publisher:

Wiley Blackwell (John Wiley & Sons)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; nitrous oxide; atmospheric lifetime; perturbation lifetime; stratospheric photochemistry; models and measurements; anthropogenic emissions