Technical Note: A diagnostic for ozone contributions of various NOx emissions in multi-decadal chemistry-climate model simulations

[摘要] Nitrogen oxide (NO_x=NO+NO₂) emissions from various sourcescontribute to the ozone budget. The identification of thesecontributions is important, e.g. for the assessment ofemissions from traffic. The non-linear character of ozonechemistry complicates the online diagnosis duringmulti-decadal chemistry-climate simulations. A methodologyis suggested, which is efficient enough to be incorporatedin multi-decadal simulations. Eight types of NO_x emissionsare included in the model. For eacha NO_y (=all N components, except N₂ and N₂O)tracer and an ozone tracer isincluded in the model, which experience the same emissions andloss processes like the online chemistry fields. To calculate theozone changes caused by an individual NO_x emission,the assumption is made thatthe NO_x relative contributions from various sourcesare identical to the NO_y relative contributions. To evaluatethis method each NO_x emissionhas been increased by 5% anda detailed error analysis is given. In the regions of themain impact of individual sourcesthe potential error of the calculated contributionis significantly smaller than the contribution.Moreover, the changes caused by an increase of theemissions of 5% were detected with a higher accuracythan the potential error of the absolute contribution.

[学科分类] 大气科学