The processes leading to the development of hail and the distribution of these events worldwide are reviewed. Microphysical and physical characteristics of hail development are described to provide context of the notable gaps in our understanding of what drives hail to grow large, or what determines how it falls to the ground. Distributional characteristics of hail are explored, utilizing both surface observations of hailstones and remotely sensed observational data sets to identify opportunities and needs for new observations. These observational deficiencies contribute to our limited capacity to both forecast hail or its expected size and reduce the effectiveness of using favorable conditions for hail development as a proxy to frequency where observations are unavailable. Given the substantive influences of both climate variability and the changing Earth system on hail, the latest understanding of their contributions to risk are addressed. Applying this understanding of the distribution and physical characteristics of hail, the damage by hail to agriculture and insured property is assessed. Much remains unknown about the processes leading to hail growth and environmental controls on hail occurrence, size, and magnitude, particularly outside of the United States and Europe. A better understanding of the global occurrence of hail is also needed to better anticipate the hazard and associated impacts.

中文翻译：

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了解地球系统中的冰雹

回顾了导致冰雹发展和这些事件在全球分布的过程。冰雹发育的微观物理和物理特征被描述为我们理解哪些因素导致冰雹长大或决定冰雹如何掉落的认识上的明显空白提供了背景。探索冰雹的分布特征，同时利用冰雹的表面观测和遥感观测数据集来确定新观测的机会和需求。这些观测缺陷导致我们有限的能力，无法预测冰雹或其预期大小，并降低了使用有利的冰雹发展条件代替无法获得观测频率的有效性。考虑到气候多变性和不断变化的地球系统对冰雹的实质性影响，将介绍对它们对风险的贡献的最新理解。根据对冰雹分布和物理特征的了解，评估了冰雹对农业和保险财产的损害。关于导致冰雹生长的过程以及对冰雹的发生，大小和大小的环境控制（尤其是在美国和欧洲以外）的过程，目前还不清楚。还需要更好地了解全球冰雹的发生，以更好地预测危害和相关影响。评估冰雹对农业和保险财产的损害。关于导致冰雹生长的过程以及对冰雹的发生，大小和大小的环境控制（尤其是在美国和欧洲以外地区）的过程，目前仍然未知。还需要更好地了解全球冰雹的发生，以更好地预测危害和相关影响。评估冰雹对农业和保险财产的损害。关于导致冰雹生长的过程以及对冰雹的发生，大小和大小的环境控制（尤其是在美国和欧洲以外地区）的过程，目前仍然未知。还需要更好地了解全球冰雹的发生，以更好地预测危害和相关影响。