Global long‐lived chemical modes excited in a 3‐D chemistry transport model: Stratospheric N2O, NOy, O3 and CH4 chemistry

The two longest-lived, major chemical response patterns (eigenmodes) of the atmosphere, coupling N2O and CH4, are identified with the UCI chemistry-transport model using a linearized (N2O, NO y , O3, CH4, H2O)-system for stratospheric chemistry and specified tropospheric losses. As in previous 1D and 2D studies, these century-long 3D simulations show that the e-folding decay time of a N2O perturbation (mode-1: 108.4 y) caused by a pulse emission of N2O is 10-years shorter than the N2O atmospheric lifetime (118.2 y). This mode-1 can also be excited by CH4emissions due to CH4-O3 stratospheric chemistry: a pulse emission of 100 Tg CH4 creates a +0.1 Tg N2O perturbation in mode-1 with a 108-yr e-folding decay time, thus increasing the CH4 global warming potential by 1.2%. Almost all of the 100 Tg CH4 appears in mode-2 (10.1 y).

[1]  L. Trefethen,et al.  Spectra and Pseudospectra , 2020 .

[2]  D. Fahey,et al.  Comparison of MkIV balloon and ER‐2 aircraft measurements of atmospheric trace gases , 1999 .

[3]  Richard G. Derwent,et al.  Transient Behaviour of Tropospheric Ozone Precursors in a Global 3-D CTM and Their Indirect Greenhouse Effects , 2001 .

[4]  M. Prather,et al.  Time scales in atmospheric chemistry: coupled perturbations to N2O, NOy, and O3 , 1998, Science.

[5]  C. McLinden,et al.  Understanding trends in stratospheric NOy and NO2 , 2001 .

[6]  W. V. Snyder,et al.  Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements , 2007 .

[7]  J. Lawton,et al.  Earth System Science , 2001, Science.

[8]  L. Trefethen.  Spectra and pseudospectra , 2005 .

[9]  C. McLinden,et al.  Stratospheric N20-NOs system' Testing uncertainties , 2001 .

[10]  O. Wild,et al.  Excitation of the primary tropospheric chemical mode in a global three-dimensional model , 2000 .

[11]  A. Mcculloch.  Halocarbon Scenarios, Ozone Depletion Potentials, and Global Warming Potentials , 2007 .

[12]  E. Dlugokencky,et al.  Atmospheric chemistry and greenhouse gases , 2001 .

[13]  H. Johnston.  Reduction of Stratospheric Ozone by Nitrogen Oxide Catalysts from Supersonic Transport Exhaust , 1971, Science.

[14]  Michael J. Prather,et al.  Lifetimes and eigenstates in atmospheric chemistry , 1994 .

[15]  M. Prather,et al.  Stratospheric variability and tropospheric ozone , 2009 .

[16]  D. Fahey,et al.  Reactive nitrogen and its correlation with ozone in the lower stratosphere and upper troposphere , 1993 .

[17]  R. Betts,et al.  Changes in Atmospheric Constituents and in Radiative Forcing. Chapter 2 , 2007 .

[18]  Hajime Akimoto,et al.  Indirect long‐term global radiative cooling from NOx Emissions , 2001 .

[19]  M. Prather.  Lifetimes and time scales in atmospheric chemistry , 2007, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[20]  Oliver Wild,et al.  Global tropospheric ozone modeling: Quantifying errors due to grid resolution , 2006 .