Understanding the climate response to stratospheric ozone depletion

臭氧层位于距地面10-30公里的平流层，吸收来自太阳的紫外线：这就是为什么它能保护我们免受皮肤癌的危害。然而，这种被吸收的紫外光也会加热平流层，使其比没有紫外线时要温暖得多。在过去的三十年里，来自喷雾罐和其他来源的化学物质在寒冷的南极平流层的冰粒上发生的化学反应中破坏了臭氧。这导致了南极洲上空春季臭氧的大幅减少：臭氧层空洞。由于臭氧的变暖效应，臭氧层空洞区域的温度比30年前要低得多，当时臭氧的存在要多得多。使用与英国气象局使用的天气预报模型类似的气候模型的计算机模拟表明，臭氧空洞不仅对平流层的温度和风产生了影响，而且一直影响到地面。这些模拟解释了过去30年观察到的南极气候的大趋势，如南大洋(南极洲周围)风的强度增加，南极洲大部分地区夏季降温，以及南极半岛变暖，那里的一个大冰架在2002年坍塌。然而，没有人真正理解臭氧在离地面10公里以上的地方减少如何会对地表的气候产生如此大的影响。这个项目的目的是用同样的气候模型来回答这个问题，该模型对臭氧消耗的反应已被证明与真实世界相比较好。通过将该模型模拟的温度和风与简化的二维模型模拟的温度和风进行比较，我们旨在找出地面对臭氧消耗的响应中有多少是由于热辐射(热)和紫外线辐射的变化，有多少是由于平流层风型的变化。我们还打算更多地了解这些反应是如何发挥作用的。我们的发现将提高我们对南极过去和未来气候变化的理解，也将有助于理解与北半球平流层相关的气候变化。由于一些研究人员发现，平流层的条件会在大约三周后影响地面天气，我们的结果甚至可能有助于改善长期天气预报。

The ozone layer, situated in the stratosphere 10-30 km above the ground, absorbs ultraviolet light from the sun: This is why it protects us from skin cancer. However, this absorbed ultraviolet light also heats the stratosphere, making it much warmer than it would otherwise be. Over the past thirty years, chemicals from aerosol spray cans and other sources have destroyed ozone in chemical reactions which take place on ice particles in the cold Antarctic stratosphere. This has led to large decreases in ozone in the spring above Antarctica: The ozone hole. Due to the warming effect of ozone, temperatures in the region of the ozone hole are much colder than they were thirty years ago when much more ozone was present. Computer simulations using a climate model similar to the weather-forecasting model used at the Met Office show that the ozone hole has had an effect on temperatures and winds not only in the stratosphere, but also all the way down to the surface. These simulations explain large trends in Antarctic climate observed over the last thirty years, such as an increase in the strength of the winds over the Southern Ocean (which surrounds Antarctica), a cooling of most of Antarctica during summer, and a warming of the Antarctic Peninsula, where a large ice shelf collapsed in 2002. However, nobody really understands how a reduction in ozone over 10 km above the ground can affect the climate at the surface so much. This project aims to answer this question using the same climate model whose response to ozone depletion has been shown to compare well with the real world. By comparing temperatures and winds simulated by this model with those from a simplified two-dimensional model, we aim to find out how much of the surface response to ozone depletion is due to changes in thermal radiation (heat) and ultraviolet radiation, and how much is due to changed wind patterns in the stratosphere. We also aim to find out more about how each of these responses works. Our findings will improve our understanding of past and future climate change in the Antarctic, and they will also be helpful for understanding climate change associated with the stratosphere in the Northern Hemisphere. Since some researchers find that conditions in the stratosphere affect surface weather around three weeks later, our results may even help to improve long range weather forecasts.