We quantified effects of dust load on the cloud top ice cloud fraction (ICF) in terms of the dust extinction coefficient (σext). We analyzed 3‐year data sets obtained from an active satellite sensor over middle to high latitudes in the northern hemisphere for temperatures (T) between 230 and 273 K and σext values between 0.005 and 0.145 km. At about 250 K, ICF changed by about 30% in response to the above range of σext, whereas at extreme T values, ICF was relatively insensitive to σext. Thus, we concluded that ICF was primarily determined by T, with substantial influence of σext at about 250 K, likely due to increased opportunities for freezing as σext increases. Sensitivity of ICFwas the lowest both at the largest σext and lowest T and at the smallest σext and highest T, while it was the highest at about 0.03 km −1 of σext and about 250 K. Plain Language Summary If there are any physical parameters that influence the ICF except temperature (T), how much does this parameter influence ICF in a given T? Dust particles have been long known as efficient ice nucleating particles. Although previous studies suggested that more dust particles increased ICF, they did not use quantitative parameters of the dust amount, but less‐quantitative indicators such as relative dust frequency. Therefore, we used the dust extinction coefficient (σext) as a quantitative parameter of dust amount and examined the relationship between the dust amount and ICF for T between 230 and 273 K. We observed the following phenomena from satellite data. At about 250 K, ICF substantially depended on σext likely due to increased opportunities for freezing as σext increases. However, at extreme T values, ICF was relatively insensitive to σext. Moreover, we found that sensitivity of ICF was the lowest both at the largest σext and lowest T and at the smallest σext and highest T, while it was the highest at about 0.03 km of σext and about 250 K. These behaviors of the ICF sensitivity could be understood from characteristics of T (the lower, the easier for freezing) and σext (the larger, the easier for freezing).

中文翻译：

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沙尘负荷对北中高纬度地区云顶冰水分布的影响与 CALIPSO 产品

我们根据尘埃消光系数 (σext) 量化了尘埃负荷对云顶冰云分数 (ICF) 的影响。我们分析了从北半球中高纬度的有源卫星传感器获得的 3 年数据集，其中温度 (T) 介于 230 和 273 K 之间，σext 值介于 0.005 和 0.145 公里之间。在大约 250 K 时，ICF 响应上述 σext 范围变化了约 30%，而在极端 T 值下，ICF 对 σext 相对不敏感。因此，我们得出结论，ICF 主要由 T 决定，σext 在大约 250 K 时有重大影响，这可能是由于随着 σext 增加冻结的机会增加。ICF的灵敏度在最大σext和最低T以及最小σext和最高T处最低，而在σext约0.03 km -1 和约250 K处灵敏度最高。简明语言总结 如果除了温度 (T) 之外，还有任何影响 ICF 的物理参数，那么在给定的 T 中，该参数对 ICF 的影响有多大？长期以来，灰尘颗粒一直被认为是有效的冰成核颗粒。虽然之前的研究表明，更多的灰尘颗粒会增加 ICF，但他们没有使用灰尘量的定量参数，而是使用较少量化的指标，例如相对灰尘频率。因此，我们使用消尘系数 (σext) 作为灰尘量的定量参数，并检查了 T 介于 230 和 273 K 之间的灰尘量与 ICF 之间的关系。我们从卫星数据中观察到以下现象。在大约 250 K 时，ICF 基本上依赖于 σext，这可能是因为随着 σext 增加冻结的机会增加。然而，在极端 T 值下，ICF 对 σext 相对不敏感。此外，我们发现ICF的灵敏度在最大σext和最低T以及最小σext和最高T处最低，而在σext约0.03 km和约250 K处最高。 ICF灵敏度的这些行为可以从T（越小越容易冻结）和σext（越大越容易冻结）的特征来理解。