We examined the sensitivity of African easterly waves (AEWs) to elevated terrain over North Africa using a numerical weather prediction model. We formed five ensembles of simulated AEW activity with orographic features independently reduced in four key regions. The ensemble members consisted of 10 consecutive AEW seasons simulated separately. From the ensembles, the southern AEW stormtrack was most sensitive to the reduction of the Ethiopian highlands. Energy budgets showed that diminished diabatic heating associated with precipitating convection was the likely driver of the weaker AEWs. Baroclinic overturning was the dominant pathway for this response. The northern AEW stormtrack was most sensitive to the reduction of the Hoggar and Tibesti mountains. In this case, a reduction in the vertical shear and diminished baroclinic energy conversions from the background state was associated with weaker AEWs. Through terrain reduction, our results provide a view of thermodynamic and dynamic feedback in AEWs that is complementary to what has been shown in past studies.

中文翻译：

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地形学对非洲东风风暴轨迹的影响

我们使用数值天气预报模型检查了非洲东风（AEW）对北非高海拔地区的敏感性。我们形成了五个模拟AEW活动的合奏，其地形特征在四个关键区域独立减少。合奏成员包括分别模拟的10个连续的AEW季节。从整体来看，南部的AEW风暴轨迹对埃塞俄比亚高地的减少最为敏感。能源预算显示，与对流加剧有关的非绝热加热的减少可能是AEW减弱的原因。斜斜倾覆是该反应的主要途径。北部的AEW风暴径对Hoggar和Tibesti山脉的减少最为敏感。在这种情况下，与背景状态相比，垂直剪切力的降低和斜压能量转换的减少与较弱的AEW有关。通过减少地形，我们的结果提供了AEW中热力学和动态反馈的观点，与以前的研究结果相辅相成。