Climate and topographic controls on snow phenology dynamics in the Tienshan Mountains, Central Asia
Climate and topographic controls on snow phenology dynamics in the Tienshan Mountains, Central Asia
复制标题
气候和地形对中亚天山雪物候动态的控制
DOI：
10.1016/j.atmosres.2019.104813
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发表时间：
2020-05-15
影响因子：
5.5
通讯作者：
Li, Zhi
中科院分区：
文献类型：
--
作者：
Li, Yupeng;Chen, Yaning;Li, Zhi
虽然以前的研究特点的季节性积雪的变化或预测积雪在气候变化，没有全面的时空分析天山，中亚地区的雪物候。根据2002/03-2017/18年中分辨率成像光谱仪（MODIS）的每日无云积雪覆盖率产品，雪覆盖持续时间（SCD）、雪开始日期（SOD）和雪结束日期（SED）），并分析了天山山区的特征。积雪物候的时空变化具有很强的海拔依赖性。SCD、SOD和SED随海拔的平均梯度分别为6.0、-2.55和3.44 d/100 m。由于太阳辐射和水汽来源的差异，北向地区的SCD一般比南向地区高，SOD一般比南向地区早，SED一般比南向地区晚。高海拔和低海拔地区的雪物候参数变化趋势相反。与近年来积雪面积的增加相一致，整个天山地区的SCD表现出明显的上升趋势，特别是在北方天山。这延长SCD更相关的先进的SOD比SED，在秋季气温下降，降水增加，有利于积雪。
Although previous studies have characterized changes in seasonal snow cover or made predictions about snow cover in a changing climate, no comprehensive spatiotemporal analysis of snow phenology has been presented for the Tienshan Mountains, Central Asia. Relying on daily cloud-free snow cover fraction products originating from Moderate Resolution Imaging Spectroradiometer (MODIS) for 2002/03-2017/18, the snow phenology parameters (i.e., snow cover duration [SCD], snow onset date [SOD] and snow end date [SED]) are derived for each hydrological year within the study period and the characteristics analyzed for the Tienshan Mountains. The spatiotemporal changes of snow phenology have strong altitude dependence. The mean gradients of SCD, SOD, and SED with elevation are 6.0, - 2.55, and 3.44 d/100 m, respectively. Because of differences in solar radiation and water vapor sources, the north-facing areas generally have a higher SCD, earlier SOD, and later SED than south-facing areas. Also, the trends of the snow phenology parameters at high and low altitudes show opposite changes. Consistent with the increase in snow cover area in recent years, SCD for the entire Tienshan region showed a clear uptick, especially in Northern Tienshan. This prolonged SCD was more related to advanced SOD than to SED, as decreased temperature and increased precipitation in autumn are conducive to snow accumulation.