Understanding the climate response to stratospheric ozone depletion

了解气候对平流层臭氧消耗的反应

• 批准号: NE/D000440/1
• 负责人: Nathan Gillett
• 金额: $ 6.61万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FD000440%2F1
• 关键词: Understanding; climate; response; stratospheric; ozone

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.

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，这就是它保护我们免受皮肤癌的原因。然而，这种被吸收的紫外线也会加热平流层，使其温度比正常情况下高得多。在过去的30年里，来自气溶胶喷雾罐和其他来源的化学物质在发生在寒冷的南极平流层的冰粒上的化学反应中破坏了臭氧。这导致了南极上空春季臭氧的大量减少：臭氧空洞。由于臭氧的变暖效应，臭氧空洞区域的温度比30年前要低得多，当时臭氧比30年前多得多。使用类似于英国气象局天气预报模型的气候模型进行的计算机模拟表明，臭氧空洞不仅对平流层的温度和风有影响，而且对地表的温度和风也有影响。这些模拟解释了过去三十年观测到的南极气候的大趋势，例如南大洋（环绕南极洲）上空的风力增强，南极洲大部分地区在夏季变冷，以及南极半岛变暖，2002年一个大冰架在那里坍塌。然而，没有人真正明白，地面以上10公里处臭氧的减少是如何对地表气候产生如此大的影响的。该项目旨在利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现实世界相比较。通过将该模型模拟的温度和风与简化二维模型模拟的温度和风进行比较，我们的目标是找出地表对臭氧消耗的响应有多少是由于热辐射（热）和紫外线辐射的变化，以及有多少是由于平流层风型的变化。我们还旨在找出更多关于这些反应是如何工作的。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，它们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状况会影响大约三周后的地面天气，我们的研究结果甚至可能有助于改善长期天气预报。