Impact of volcanic aerosols on stratospheric ozone recovery
Impact of volcanic aerosols on stratospheric ozone recovery
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火山气溶胶对平流层臭氧恢复的影响
DOI：
10.1002/2016jd025808
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
M. Lin
中科院分区：
文献类型：
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作者：
V. Naik;L. Horowitz;M. Daniel Schwarzkopf;M. Lin
我们使用瞬态GFDL-CM 3化学气候模式模拟2006-2100年期间，以显示火山气溶胶对臭氧恢复的程度和时间的影响如何随（a）未来温室气体情景（代表性浓度途径（RCP）4.5和RCP 8.5）和（B）卤素负荷而变化。目前的理解是，升高的火山气溶胶在高卤素负荷下减少臭氧，但在低卤素负荷下增加臭氧，当化学反应更多地是NOx主导时。在气溶胶载量极低的情况下（此处称为“背景”），在RCP8.5假设情景中，全球平流层臭氧负担模拟将在2050年左右恢复到1980年的水平，但在RCP4.5假设情景中，整个世纪仍低于1980年的水平。相比之下，随着火山气溶胶的增加，臭氧柱恢复到1980年水平的速度更快，RCP8.5的恢复日期从21世纪40年代中期到RCP4.5的21世纪50年代中期到21世纪70年代初。臭氧在两种未来排放情景中的响应随着火山气溶胶的增加而增加。到2100年，与使用极低背景气溶胶的模拟相比，在RCP8.5中，1980年基线调整后的全球平流层臭氧柱预计将增加20-40%，在RCP4.5中，火山气溶胶增加110-200%。在2100年，RCP8.5中由于火山气溶胶升高而产生的臭氧增强比RCP4.5中的臭氧增强弱，这是由于RCP8.5中的甲烷比RCP4.5高2.5倍。我们的研究结果表明，在平流层臭氧预测和预期的恢复日期引起的火山气溶胶扰动，需要考虑在未来的模式臭氧预测的重大不确定性。
We use transient GFDL‐CM3 chemistry‐climate model simulations over the 2006–2100 period to show how the influence of volcanic aerosols on the extent and timing of ozone recovery varies with (a) future greenhouse gas scenarios (Representative Concentration Pathway (RCP)4.5 and RCP8.5) and (b) halogen loading. Current understanding is that elevated volcanic aerosols reduce ozone under high halogen loading but increase ozone under low halogen loading when the chemistry is more NOx dominated. With extremely low aerosol loadings (designated here as “background”), global stratospheric ozone burden is simulated to return to 1980 levels around 2050 in the RCP8.5 scenario but remains below 1980 levels throughout the 21st century in the RCP4.5 scenario. In contrast, with elevated volcanic aerosols, ozone column recovers more quickly to 1980 levels, with recovery dates ranging from the mid‐2040s in RCP8.5 to the mid‐2050s to early 2070s in RCP4.5. The ozone response in both future emission scenarios increases with enhanced volcanic aerosols. By 2100, the 1980 baseline‐adjusted global stratospheric ozone column is projected to be 20–40% greater in RCP8.5 and 110–200% greater in RCP4.5 with elevated volcanic aerosols compared to simulations with the extremely low background aerosols. The weaker ozone enhancement at 2100 in RCP8.5 than in RCP4.5 in response to elevated volcanic aerosols is due to a factor of 2.5 greater methane in RCP8.5 compared with RCP4.5. Our results demonstrate the substantial uncertainties in stratospheric ozone projections and expected recovery dates induced by volcanic aerosol perturbations that need to be considered in future model ozone projections.