Why have space weather forecasts not improved for over a decade?

为什么太空天气预报十多年来没有改善？

• 批准号: NE/Y001052/1
• 负责人: Mathew Owens
• 金额: $ 50.41万
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY001052%2F1
• 关键词: Why; space; weather; forecasts; improved

The solar wind is a continual outflow of material from the Sun, which fills the solar system. Rapid changes in the solar wind conditions in near-Earth space have consequences for technologies in space and on the ground, most notably the power grid. It also poses a radiation threat to humans on high altitude flights and in space, such as future crewed missions to the moon and Mars. For these reasons, such "space weather" features prominently on the UK National Risk register; accurate space-weather forecasting a goal of critical importance.In order to mitigate against the costly, and sometimes dangerous, impacts of space weather, it is necessary to provide adequate warning time of an incoming event. As the solar wind always flows away from the Sun, forecasting further into the future effectively means starting the forecasts with information from closer to the Sun. Currently, the Met Office (and other international forecast agencies) uses remote observations of the Sun's surface and lower atmosphere in conjunction with computer models in order to forecast space weather 2-4 days into the future. Unfortunately, the accuracy with which these state-of-the-art methods can forecast the time of onset of the severe space weather is both insufficient to be useful for many applications, and has not improved for more than a decade. However, there are measurements of the solar wind being routinely made that are not currently being used by the models. Using methods developed at the University of Reading over the last 4-5 years, we have shown that solar wind forecasts can be significantly improved by ingesting these observations into the models using a technique called data assimilation (DA). We will employ our new solar wind DA methods to determine what factors most influence space-weather forecast accuracy and, consequently, what are the fundamental limits to how accurate forecasting can hope to reach. We will also adapt our solar wind DA methods to work with the Met Office's forecast models, providing a significant improvement in future space-weather forecasting. This will have wide societal benefits, as both satellite operation and the power grids can be impacted by space weather.

太阳风是太阳不断流出的物质，充满了太阳系。近地空间太阳风条件的快速变化对空间和地面技术，尤其是电网产生了影响。它还对高空飞行和太空中的人类构成辐射威胁，比如未来的月球和火星载人飞行任务。由于这些原因，这种“太空天气”在英国国家风险登记册上占有显著地位；准确的空间天气预报是一个至关重要的目标。为了减轻空间天气带来的代价高昂、有时甚至是危险的影响，有必要为即将到来的事件提供足够的预警时间。由于太阳风总是远离太阳的，所以预测未来就意味着从更接近太阳的信息开始预测。目前，英国气象局（和其他国际预报机构）利用对太阳表面和低层大气的远程观测，结合计算机模型来预测未来2-4天的太空天气。不幸的是，这些最先进的方法预测恶劣空间天气开始时间的准确性不仅不足以用于许多应用，而且十多年来没有得到改善。然而，有一些太阳风的常规测量，目前还没有被模型使用。利用雷丁大学在过去4-5年里开发的方法，我们已经证明，通过使用一种称为数据同化（DA）的技术将这些观测数据纳入模型，可以显著提高太阳风预报的质量。我们将采用新的太阳风数据分析方法来确定哪些因素最能影响空间天气预报的准确性，从而确定预测准确度的基本限制是什么。我们还将调整我们的太阳风数据分析方法，使之与英国气象局的预报模型协同工作，为未来的空间天气预报提供重大改进。这将带来广泛的社会效益，因为卫星运行和电网都可能受到太空天气的影响。