How does the aurora heat the upper atmosphere?

极光如何加热高层大气？

• 批准号: NE/S015167/1
• 负责人: Daniel Whiter
• 金额: $ 67.51万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS015167%2F1
• 关键词: How; does; aurora; heat; upper

My research will study the aurora, a beautiful display caused by energetic particles from space hitting the Earth's atmosphere at about 40 million mph. The aurora typically deposits 50 GW of power into the atmosphere, comparable to the electricity consumption of the UK. This huge energy source has considerable influence on the temperature and composition of the upper atmosphere, particularly in polar regions. The aurora is therefore one of many ingredients needed for computer simulations of the whole atmosphere, which predict changes to Earth's climate and to concentrations of gases such as ozone.Intense currents flow within and around aurora, heating the atmosphere just as an electric current heats a resistor. This heating has dramatic effects on the upper atmosphere, but several fundamental aspects remain undetermined. Previously it has been very difficult to measure the temperature of the atmosphere at auroral heights; it is too high for weather balloons, but too low for spacecraft. However, I recently made the exciting discovery, through experiment and theory, that the ratio of brightnesses of two specific auroral colours depends on the temperature of the atmosphere; therefore by observing these wavelengths in the aurora we can calculate the temperature. My idea is to use extremely sensitive cameras equipped with colour filters to make maps of atmospheric temperature, just like a thermal imaging camera. These temperature maps can be combined with radar measurements of the upper atmosphere to estimate the electrical conductivity, which is an important property influencing the flow of electric current through near-Earth space and the atmosphere. A computer simulation will help me to understand how different types of aurora are produced, what electric currents they generate, and how the aurora affects the temperature and chemistry of the upper atmosphere.

我的研究将研究极光，这是一种美丽的显示，是由来自太空的高能粒子以每小时4000万英里的速度撞击地球大气层造成的。极光通常会向大气中沉积50吉瓦的电力，相当于英国的电力消耗。这种巨大的能源对高层大气的温度和组成有相当大的影响，特别是在极地地区。因此，极光是计算机模拟整个大气层所需的众多成分之一，这些成分可以预测地球气候和臭氧等气体浓度的变化。极光内部和周围有强烈的电流流动，加热大气层，就像电流加热电阻器一样。这种加热对高层大气产生了巨大的影响，但几个基本方面仍然没有确定。以前，测量极光高度的大气温度非常困难;它对气象气球来说太高，但对航天器来说又太低。然而，我最近通过实验和理论取得了令人兴奋的发现，即两种特定极光颜色的亮度比率取决于大气温度;因此，通过观察极光中的这些波长，我们可以计算温度。我的想法是使用配备彩色滤光片的极敏感相机来绘制大气温度图，就像热成像相机一样。这些温度图可与高层大气的雷达测量相结合，以估计电导率，电导率是影响电流在近地空间和大气中流动的一个重要特性。计算机模拟将帮助我了解不同类型的极光是如何产生的，它们产生什么电流，以及极光如何影响高层大气的温度和化学成分。

项目成果

Multiscale Observation of Two Polar Cap Arcs Occurring on Different Magnetic Field Topologies

• DOI: 10.1029/2019ja027611
• 发表时间: 2020-08
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: J. Reidy;J. Reidy;R. Fear;D. Whiter;B. Lanchester;A. Kavanagh;Daniel J. Price;J. Chadney;Yongliang Zhang;L. Paxton

Diffuse and Pulsating Aurora

• DOI: 10.1007/s11214-019-0629-3
• 发表时间: 2020-01
• 期刊: Space Science Reviews
• 影响因子: 10.3
• 作者: Y. Nishimura;M. Lessard;Y. Katoh;Y. Miyoshi;E. Grono;N. Partamies;Nithin Sivadas;K. Hosokawa;M. Fukizawa;M. Samara;R. Michell;R. Kataoka;T. Sakanoi;D. Whiter;S. Oyama;Y. Ogawa;S. Kurita

Fine-Scale Electric Fields and Joule Heating From Observations of the Aurora

极光观测中的精细电场和焦耳热

• DOI: 10.1029/2022ja030628
• 发表时间: 2023
• 期刊: Space Physics
• 作者: Krcelic P

Morphological evolution and spatial profile changes of poleward moving auroral forms

• DOI: 10.5194/angeo-41-115-2023
• 发表时间: 2023-03
• 期刊: Annales Geophysicae
• 影响因子: 1.9
• 作者: A. Goertz;N. Partamies;D. Whiter;L. Baddeley

Characteristics of fragmented aurora-like emissions (FAEs) observed on Svalbard

在斯瓦尔巴群岛观测到的碎片状极光发射（FAE）的特征

• DOI: 10.5194/angeo-39-277-2021
• 发表时间: 2021
• 期刊: Annales Geophysicae
• 影响因子: 1.9
• 作者: Dreyer J