Abstract The variables of snow cover extent (SCE), snow cover duration (SCD), and snow albedo (SAL) are primary factors determining the surface energy balance and hydrological response of the cryosphere, influencing snow pack and glacier mass-balance, melt, and runoff conditions. This study examines spatiotemporal patterns and trends in SCE, SCD, and SAL (2000–2016; 16 years) for central Chilean and Argentinean Andes using the MODIS MOD10A1 C6 daily snow product. Observed changes in these variables are analyzed in relation to climatic variability by using ground truth observations (meteorological data from the El Yeso Embalse and Valle Nevado weather stations) and the Multivariate El Nino index (MEI) data. We identified significant downward trends in both SCE and SAL, especially during the onset and offset of snow seasons. SCE and SAL showed high inter-annual variability which correlate significantly with MEI applied with a one-month time-lag. SCE and SCD decreased by an average of ~13 ± 2% and 43 ± 20 days respectively, over the study period. Analysis of spatial pattern of SCE indicates a slightly greater reduction on the eastern side (~14 ± 2%) of the Andes Cordillera compared to the western side (~12 ± 3%). The downward SCE, SAL, and SCD trends identified in this study are likely to have adverse impacts on downstream water resource availability to agricultural and densely populated regions in central Chile and Argentina.

中文翻译：

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智利和阿根廷中部安第斯山脉的积雪和积雪反照率变化来自每日 MODIS 观测（2000-2016）

摘要 积雪范围（SCE）、积雪持续时间（SCD）和积雪反照率（SAL）变量是决定冰冻圈表面能量平衡和水文响应的主要因素，影响积雪和冰川质量平衡、融化、和径流条件。本研究使用 MODIS MOD10A1 C6 日积雪检查智利中部和阿根廷安第斯山脉的 SCE、SCD 和 SAL（2000-2016 年；16 年）的时空模式和趋势。通过使用地面实况观测（来自 El Yeso Embalse 和 Valle Nevado 气象站的气象数据）和多变量厄尔尼诺指数 (MEI) 数据，分析这些变量中观测到的变化与气候变异的关系。我们确定了 SCE 和 SAL 的显着下降趋势，尤其是在雪季开始和偏移期间。SCE 和 SAL 显示出较高的年际变异性，这与应用的 MEI 显着相关，时滞为 1 个月。在研究期间，SCE 和 SCD 分别平均下降了约 13 ± 2% 和 43 ± 20 天。对 SCE 空间格局的分析表明，与西侧 (~12 ± 3%) 相比，安第斯山脉东侧 (~14 ± 2%) 的减少幅度略大。本研究中确定的 SCE、SAL 和 SCD 下降趋势可能会对智利中部和阿根廷中部农业和人口稠密地区的下游水资源可用性产生不利影响。对 SCE 空间格局的分析表明，与西侧 (~12 ± 3%) 相比，安第斯山脉东侧 (~14 ± 2%) 的减少幅度略大。本研究中确定的 SCE、SAL 和 SCD 下降趋势可能会对智利中部和阿根廷中部农业和人口稠密地区的下游水资源可用性产生不利影响。对 SCE 空间格局的分析表明，与西侧 (~12 ± 3%) 相比，安第斯山脉东侧 (~14 ± 2%) 的减少幅度略大。本研究中确定的 SCE、SAL 和 SCD 下降趋势可能会对智利中部和阿根廷中部农业和人口稠密地区的下游水资源可用性产生不利影响。