NOx and HOx production by energetic electrons and impacts on polar stratospheric ozone (NOHO)

高能电子产生 NOx 和 HOx 及其对极地平流层臭氧 (NOHO) 的影响

基本信息

批准号：
NE/J02077X/1
负责人：
John Plane
金额：
$ 28.31万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2013
资助国家：
英国
起止时间：
2013 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ02077X%2F1
关键词：
NOx HOx production energetic electrons

项目摘要

Predicting future climate change is intimately linked to understanding what is happening to the climate system in the present, and in the recent past. Studies in the Polar Regions provide vital clues in our understanding of global climate, and early indications of changes arising from the coupling of natural processes, such as variability in the amount of energy from the Sun reaching the Earth, and man-made factors. For example, the polar winter provides the extreme cold, dark conditions in the atmosphere which, combined with chemicals released from man-made chlorofluorocarbon (CFC) gases, has led to destruction of the stratospheric ozone layer 18-25 km above the ground every spring-time since the 1980's. The Southern hemisphere ozone 'hole' is now linked to observed changes in surface temperature and sea-ice across Antarctica, decreased uptake of carbon dioxide by the Southern Ocean, and perturbations to the atmospheric circulation that can affect weather patterns as far away as the Northern hemisphere.Recovery of the ozone layer is expected now that CFC's are banned by international protocols, but this may be delayed by other greenhouse gases we are releasing into the atmosphere and natural processes including changes in the Sun's output. Although the total amount of energy as sunlight changes by a small amount (~0.1%) over the typical 11-year solar cycle, the energetic electrons and protons streaming from the Sun changes dramatically on timescales from hours to years. These particles are guided by the Earth's magnetic field and can enter the upper atmosphere, most intensely over the Polar Regions. A visible effect is the aurora, but the particles can also significantly modify the chemistry of the atmosphere down to the stratospheric ozone layer. Powerful solar storms can also damage satellites and disrupt electrical power networks. However the mechanisms by which energetic electrons generated by the Sun enter the Earth's atmosphere, and the complex, interacting processes that affect stratospheric ozone are not well understood, which limits our ability to accurately predict future ozone changes and impacts on climate.We propose answering major unresolved questions about the impact of energetic electrons on stratospheric ozone by making observations of the middle atmosphere from Halley station in Antarctica. This location is directly under the main region where energetic electrons enter the atmosphere, making it ideal to observe the resulting effects. We will install a state-of-the-art microwave radiometer there alongside other equipment run by BAS scientists. By analysing the microwaves naturally emitted by the atmosphere high above us we can work out how much ozone there is 30-90 km above the ground as well as measuring chemicals produced in the atmosphere by energetic electrons that affect ozone. We will make observations throughout two complete Antarctic years/winters (1/2013-2/2015) and interpret them with the help of data from spacecraft that orbit the Earth and measure the energetic electrons entering the atmosphere. We will use the Antarctic observations and develop computer-based models to better understand the impact of energetic electrons on the atmosphere. The ultimate goal is to further understanding of the processes that lead to climate variability in the Polar Regions and globally - highly relevant for UK environmental science and collaborative research at an international level in which BAS and Leeds play a key role.

预测未来的气候变化与了解当前和过去的气候系统正在发生的事情密切相关。极地区域的研究为我们对全球气候的理解提供了重要的线索，以及自然过程耦合所产生的变化的早期迹象，例如从太阳到达地球的能量量的可变性以及人为的因素。例如，极地冬季在大气中提供了极端的寒冷，黑暗的条件，结合从人造氯氟碳（CFC）气体释放的化学物质，导致每年春季18-25 km上方18-25 km的平流层臭氧层破坏 - 自1980年代以来的时间。现在，南半球臭氧“孔”与观察到的南极的表面温度和海冰变化有关，南部海洋降低了二氧化碳的吸收，并与大气循环的扰动可能会影响天气模式，从而影响北部的天气模式半球。既然CFC被国际协议禁止，则预计臭氧层的发现可能会被其他温室气体延迟，而我们正在进入大气和自然过程中，包括太阳产量的变化。尽管在典型的11年太阳周期中，作为阳光的总能量随着阳光而变化少量（〜0.1％），但来自太阳流出的能量电子和质子在时间尺度上从小时到几年发生了巨大变化。这些颗粒由地球的磁场引导，并且可以进入高层大气，最强烈地在极地区域。可见的效果是极光，但是颗粒也可以显着将大气的化学变化为平流层臭氧层。强大的太阳风暴也会损坏卫星并破坏电力网络。然而，太阳产生的能量电子进入地球大气的机制以及影响平流层臭氧的复杂的，相互作用的过程尚不清楚，这限制了我们准确预测未来臭氧的变化和对气候的影响的能力。通过观察到南极洲的Halley Station的中间大气，对高能电子对平流层臭氧的影响的未解决问题。该位置直接在能量电子进入大气的主要区域下，使观察产生的影响是理想的选择。我们将与BAS科学家运行的其他设备一起在那里安装最先进的微波辐射计。通过分析高于我们上方的大气自然发射的微波，我们可以弄清地面上方有30-90公里的臭氧，并通过影响臭氧的能量电子在大气中产生的化学物质。我们将在两个完整的南极/冬季（1/2013-2/2015）中进行观察，并借助来自地球绕地球的航天器的数据来解释它们，并测量进入大气的能量电子。我们将使用南极观察结果并开发基于计算机的模型，以更好地了解能量电子对大气的影响。最终目标是进一步理解导致极地地区气候变化和全球气候变化的过程 - 与英国环境科学和协作研究高度相关，在国际层面上，BAS和利兹在该层面上起着关键作用。