Abstract. Understanding the mechanisms controlling glacial retreat in the tropical Andes can strengthen future predictions of ice cover in the region. As glaciers are a dominant freshwater source in these regions, accurate ice cover predictions are necessary for developing effective strategies to protect future water resources. In this study, we investigated a 97-year dust record from two Nevado Illimani ice cores to determine the dominant factors controlling particle concentration and size distribution. In addition, we measured the area of a Nevado Illimani glacier (glacier n°8) using aerial photographs from 1956 and 2009. We identified two dustier periods during the 20th century (1930s–1940s and 1980s–2016), which were linked to reduced moisture transport from the Amazon basin. This promoted an unprecedented increase in the percentage of coarse dust particles (CPPn, ∅ > 10 μm) during the 1990s, as drier local conditions favored the emission and deposition of coarse particles on the glacier. Moisture advection from the Amazon basin to Nevado Illimani was influenced by tropical North Atlantic sea surface temperatures (TNA), which was supported by the correlation between TNA and CPPn (r = 0.52). Furthermore, glacial retreat has been accelerating since the 1980s, and a notable relationship between CPPn and the freezing level height (FLH, r = 0.41) was observed. This suggests that higher FLHs promote glacial retreat, which exposes fresh glacial sediments and facilitates the transport of coarse dust particles to the Nevado Illimani summit. Therefore, both the area of glacier n°8 and the ice core record of coarse dust particles were found to respond to climate variability—particularly to the warmer conditions across the southern tropical Andes and drier conditions over the Amazon basin.

中文翻译：

---

热带安第斯山脉（内华达州伊利马尼–玻利维亚）冰芯中的尘埃记录，可能对亚马逊河流域的气候变化进行分析

摘要。了解控制热带安第斯山脉冰川退缩的机制可以加强对该地区冰盖的未来预测。由于冰川是这些地区的主要淡水来源，因此准确的冰盖预测对于制定保护未来水资源的有效策略是必要的。在这项研究中，我们调查了两个内华达州伊利马尼冰芯的97年灰尘记录，以确定控制颗粒浓度和尺寸分布的主要因素。此外，我们使用1956年至2009年的航拍照片测量​​了内华达州伊利马尼冰川（n°8冰川）的面积。我们确定了20世纪的两个较尘埃期（1930s–1940s和1980s–2016年），这与减少来自亚马逊盆地的水分输送。在1990年代，由于干燥的当地条件有利于在冰川上散发和沉积粗颗粒，这促使粗尘颗粒（CPPn，∅> 10μm）的百分比空前增加。北亚热带海平面温度（TNA）影响了从亚马逊河流域到内华多伊利马尼河的平流，而TNA和CPPn之间的相关性支持了这一趋势（r = 0.52）。此外，自1980年代以来，冰川退缩一直在加速，并且观测到CPPn与冰冻高度之间的显着关系（FLH，r = 0.41）。这表明较高的FLH促进了冰川的退缩，从而使新鲜的冰川沉积物暴露出来，并促进了粗尘埃颗粒向内华达州伊利马尼峰的运输。因此，