Abstract Explosive volcanic eruptions can inject large amounts of ash and gases into the atmosphere. Such volcanic aerosols can have a significant impact on the surrounding environment, and there is the need to closely investigate their effects on meteorology on local, regional, and even continental scale. This work presents a study of the 2010 Eyjafjallajokull volcanic eruption the resulting ash dispersion and its radiative feedback effects on the meteorological conditions with the Weather Research Forecasting model with on-line Chemistry (WRF-Chem). Two model runs, one meteorology-only simulation (without chemistry) and one that considers gas- and aerosol chemistry as well as direct- and semidirect aerosol feedbacks were performed and compared. Results for daily values show that aerosol radiative feedback effects can cool the atmosphere close to the surface on average by 1 °C with maximum cooling exceeding even 2 °C for the considered episode. Near-surface atmospheric wind speed changed on average by 0.5 m/s with maximum values above 2 m/s. Furthermore, the presence of ash aerosols affected the vertical shape of the profiles of wind speed and temperature and resulted in a better agreement with radiosonde measurements when radiative feedback effects were considered. Although the modeling of the dispersion of volcanic ash clouds is subject to large uncertainties, we have demonstrated that the WRF-Chem model can reproduce observations at surface levels and vertical profiles more realistically when radiative feedback effects are considered in the simulations.

中文翻译：

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2010 年 4 月和 5 月 Eyjafjallajökull 喷发期间使用 WRF-Chem 模拟火山气溶胶辐射反馈的影响

摘要 火山爆发会向大气中注入大量的火山灰和气体。此类火山气溶胶会对周围环境产生重大影响，需要在局地、区域甚至大陆尺度上密切研究它们对气象的影响。这项工作通过天气研究预测模型和在线化学 (WRF-Chem) 对 2010 年埃亚菲亚德拉冰盖火山喷发、由此产生的灰烬扩散及其对气象条件的辐射反馈影响进行了研究。执行并比较了两个模型运行，一个仅用于气象学的模拟（没有化学）和一个考虑气体和气溶胶化学以及直接和半直接气溶胶反馈的模拟。每日值的结果表明，气溶胶辐射反馈效应可以将接近地表的大气平均冷却 1°C，对于所考虑的事件，最大冷却甚至超过 2°C。近地表大气风速平均变化 0.5 m/s，最大值超过 2 m/s。此外，灰气溶胶的存在影响了风速和温度剖面的垂直形状，并在考虑辐射反馈效应时与无线电探空仪测量结果更好地吻合。尽管火山灰云扩散的建模存在很大的不确定性，但我们已经证明，当在模拟中考虑辐射反馈效应时，WRF-Chem 模型可以更真实地再现地表和垂直剖面的观测结果。