Fernandez Rafael P, Barrera Javier A, López-Noreña Ana Isabel, Kinnison Douglas E, Nicely Julie, Salawitch Ross J, Wales Pamela A, Toselli Beatriz M, Tilmes Simone, Lamarque Jean-François, Cuevas Carlos A, Saiz-Lopez Alfonso
Department of Atmospheric Chemistry and Climate Institute of Physical Chemistry Rocasolano CSIC Madrid Spain.
Institute for Interdisciplinary Science National Research Council (ICB-CONICET) Mendoza Argentina.
Geophys Res Lett. 2021 Feb 28;48(4):e2020GL091125. doi: 10.1029/2020GL091125. Epub 2021 Feb 23.
Many Chemistry-Climate Models (CCMs) include a simplified treatment of brominated very short-lived (VSL) species by assuming CHBr as a surrogate for VSL. However, neglecting a comprehensive treatment of VSL in CCMs may yield an unrealistic representation of the associated impacts. Here, we use the Community Atmospheric Model with Chemistry (CAM-Chem) CCM to quantify the tropospheric and stratospheric changes between various VSL chemical approaches with increasing degrees of complexity (i.e., surrogate, explicit, and full). Our CAM-Chem results highlight the improved accuracy achieved by considering a detailed treatment of VSL photochemistry, including sea-salt aerosol dehalogenation and heterogeneous recycling on ice-crystals. Differences between the full and surrogate schemes maximize in the lowermost stratosphere and midlatitude free troposphere, resulting in a latitudinally dependent reduction of ∼1-7 DU in total ozone column and a ∼5%-15% decrease of the OH/HO ratio. We encourage all CCMs to include a complete chemical treatment of VSL in the troposphere and stratosphere.
许多化学气候模型（CCMs）通过假定CHBr作为极短寿命（VSL）物种的替代物，对溴化极短寿命物种进行了简化处理。然而，在CCMs中忽略对VSL的全面处理可能会导致对相关影响的不切实际的描述。在这里，我们使用带有化学模块的社区大气模型（CAM-Chem）CCM来量化随着复杂度增加（即替代、显式和完整）的各种VSL化学方法之间对流层和平流层的变化。我们的CAM-Chem结果突出了通过考虑对VSL光化学的详细处理所实现的更高精度，包括海盐气溶胶脱卤和冰晶上的非均相再循环。完整方案和替代方案之间的差异在最低平流层和中纬度自由对流层中最大，导致总臭氧柱在纬度上依赖的减少约1 - 7杜，以及OH/HO比率降低约5% - 15%。我们鼓励所有CCMs对流层和平流层中的VSL进行完整的化学处理。
