Polar Stratospheric Clouds: Satellite Observations, Processes, and Role in Ozone Depletion
Polar Stratospheric Clouds: Satellite Observations, Processes, and Role in Ozone Depletion
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DOI：
10.1029/2020rg000702
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发表时间：
2021-03
影响因子：
25.2
通讯作者：
I. Tritscher;M. Pitts;L. Poole;T. Peter
中科院分区：
文献类型：
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作者：
I. Tritscher;M. Pitts;L. Poole;T. Peter
极地平流层云（PSC）在冬季和春季高纬度地区的平流层臭氧消耗中起着重要作用（例如，南极臭氧层空洞）。PSC颗粒为多相反应提供场所，该多相反应将稳定的氯储库物质转化为催化破坏臭氧的自由基。PSC还通过大硝酸三水合物（NAT）和冰粒的沉降去除气相HNO 3和H2O来延迟氯失活，从而延长臭氧消耗。星载仪器迈克尔逊被动大气探测干涉仪（MIPAS）、微波临边探测仪（MLS）和正交偏振云气溶胶激光雷达（CALIOP）的当代观测提供了前所未有的极地涡旋范围内的气候学观点两个半球的PSC发生和组成。这些数据促进了我们对PSC形成和相关动力学过程的理解，特别是NAT和冰PSC粒子的广泛异质成核的有力证据，也许是陨石起源的核。非均相氯活化似乎是很好理解的。液滴上/液滴中的反应系数已经被精确测量，虽然固体NAT和冰粒上的反应仍然存在不确定性，但它们被认为相对不重要，因为在大多数条件下，氯活化发生在液滴上/液滴中。在化学输送和化学气候模型再现从空间观测到的PSC时空分布和组成的能力方面取得了显著进展。持续的空间PSC观测将有助于进一步改进PSC过程在全球模型中的表现，并能够更准确地预测极地臭氧和全球臭氧层随气候变化的演变情况。
Polar stratospheric clouds (PSCs) play important roles in stratospheric ozone depletion during winter and spring at high latitudes (e.g., the Antarctic ozone hole). PSC particles provide sites for heterogeneous reactions that convert stable chlorine reservoir species to radicals that destroy ozone catalytically. PSCs also prolong ozone depletion by delaying chlorine deactivation through the removal of gas‐phase HNO3 and H2O by sedimentation of large nitric acid trihydrate (NAT) and ice particles. Contemporary observations by the spaceborne instruments Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), Microwave Limb Sounder (MLS), and Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) have provided an unprecedented polar vortex‐wide climatological view of PSC occurrence and composition in both hemispheres. These data have spurred advances in our understanding of PSC formation and related dynamical processes, especially the firm evidence of widespread heterogeneous nucleation of both NAT and ice PSC particles, perhaps on nuclei of meteoritic origin. Heterogeneous chlorine activation appears to be well understood. Reaction coefficients on/in liquid droplets have been measured accurately, and while uncertainties remain for reactions on solid NAT and ice particles, they are considered relatively unimportant since under most conditions chlorine activation occurs on/in liquid droplets. There have been notable advances in the ability of chemical transport and chemistry‐climate models to reproduce PSC temporal/spatial distributions and composition observed from space. Continued spaceborne PSC observations will facilitate further improvements in the representation of PSC processes in global models and enable more accurate projections of the evolution of polar ozone and the global ozone layer as climate changes.