TY - JOUR
T1 - The impact of NOx emissions from lightning on the production of aviation-induced ozone
AU - Khodayari, Arezoo
AU - Vitt, Francis
AU - Phoenix, Daniel
AU - Wuebbles, Donald J.
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/8
Y1 - 2018/8
N2 - Due to the non-linear nature of ozone production in the troposphere, ozone production as a function of aviation nitrogen oxide (NOx = NO + NO2) emissions varies based on the background NOx levels. Of the several different sources of background NOx in the atmosphere, NOx from lightning (LNOx) contributes a substantial amount of NOx to the upper troposphere and has an effect on the ozone production efficiency, even though the LNOx source still has significant uncertainty. In this study, CAM5, the atmospheric component of the Community Earth System Model (CESM), was used to study the effect of uncertainties in NOx emissions from lightning on the production of aviation-induced ozone. Three sensitivity studies were analyzed with varying LNOx values of 3.7, 5, and 7.4 TgN/yr, representing the best current range estimates for LNOx. Results show a decrease in the aviation-induced ozone production rate and radiative forcing (RF) as LNOx increases. This is tied to the decreased ozone production under NOx saturated conditions. The ozone production per unit of NOx emission from lightning ranges from 2.38 TgO3/TgN for the case with 3.7 TgN from lightning to 0.97 TgO3/TgN for the case with 7.4 TgN from lightning. Similarly, the O3 RF decreases from 43.9 mW/m2 for the 3.7 TgN/yr case to 34.3 mW/m2 for 7.4 TgN/yr case. Understanding the current sensitivity of aviation-induced ozone production to the LNOx strength is important for reducing the uncertainty in ozone production from aviation NOx emissions.
AB - Due to the non-linear nature of ozone production in the troposphere, ozone production as a function of aviation nitrogen oxide (NOx = NO + NO2) emissions varies based on the background NOx levels. Of the several different sources of background NOx in the atmosphere, NOx from lightning (LNOx) contributes a substantial amount of NOx to the upper troposphere and has an effect on the ozone production efficiency, even though the LNOx source still has significant uncertainty. In this study, CAM5, the atmospheric component of the Community Earth System Model (CESM), was used to study the effect of uncertainties in NOx emissions from lightning on the production of aviation-induced ozone. Three sensitivity studies were analyzed with varying LNOx values of 3.7, 5, and 7.4 TgN/yr, representing the best current range estimates for LNOx. Results show a decrease in the aviation-induced ozone production rate and radiative forcing (RF) as LNOx increases. This is tied to the decreased ozone production under NOx saturated conditions. The ozone production per unit of NOx emission from lightning ranges from 2.38 TgO3/TgN for the case with 3.7 TgN from lightning to 0.97 TgO3/TgN for the case with 7.4 TgN from lightning. Similarly, the O3 RF decreases from 43.9 mW/m2 for the 3.7 TgN/yr case to 34.3 mW/m2 for 7.4 TgN/yr case. Understanding the current sensitivity of aviation-induced ozone production to the LNOx strength is important for reducing the uncertainty in ozone production from aviation NOx emissions.
KW - Aviation-induced ozone
KW - lightning NOx
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U2 - 10.1016/j.atmosenv.2018.05.057
DO - 10.1016/j.atmosenv.2018.05.057
M3 - Article
AN - SCOPUS:85048446534
SN - 1352-2310
VL - 187
SP - 410
EP - 416
JO - Atmospheric Environment
JF - Atmospheric Environment
ER -