A Case Study on Fog/Low Stratus Occurrence at Las Lomitas, Atacama Desert (Chile) as a Water Source for Biological Soil Crusts
A Case Study on Fog/Low Stratus Occurrence at Las Lomitas, Atacama Desert (Chile) as a Water Source for Biological Soil Crusts
复制标题
DOI：
10.4209/aaqr.2017.01.0021
复制
发表时间：
2018-01-01
影响因子：
4
通讯作者：
Bendix, Joerg
中科院分区：
文献类型：
--
作者：
Lehnert, Lukas W.;Thies, Boris;Bendix, Joerg
阿塔卡马沙漠以太平洋上空以低层云(LST)形式出现的大范围雾(空间范围：数百公里)而闻名。相比之下，小规模和异质性的雾(数百米)的出现，特别是在夏季，普遍没有考虑到。然而，这些事件对于当地的植被，特别是对广泛分布在这个极端生态系统中的生物土壤结壳(BSC)来说是重要的。因此，在潘德阿祖卡国家公园的一个典型雾化绿洲中进行了案例研究，以测试将现场测量、无人机剖面、遥感和数值模拟相结合的可行性，(I)调查雾型在动力学、物理性质和形成方面的具体差异，(Ii)测试基于现有低分辨率和拟议的新的高分辨率产品进行雾监测的遥感技术的适用性，以及(Iii)估计输入到BSC的相关雾水。观测到了两种雾。太平洋上出现的高航道、大空间范围的大雾/大雾甲板是第一种类型。第二类雾较零星，尺度较小，不一定与大洋上空的低层温度有关。相反，第二类雾的形成与热风系统有关，热风系统产生的浅层云比第一类云的水分少。一般来说，现有的遥感产品没有很好地捕捉到这种小范围的雾事件，但拟议的新的高分辨率产品可以探测到，这一产品提供了有希望的结果。这两种雾类型都是浮标系统的重要水资源，约有8%至24%的雾水通量可供浮标系统使用。结果表明，所提出的方法池在未来的高空间分辨率下估算BSCs的水量平衡是可行的。
The Atacama Desert is well known for the high occurrence of large-scale fog (spatial extents: hundreds of kilometers) emerging as low stratus (LST) decks over the Pacific Ocean. By contrast, the small-scale and heterogeneous occurrence of small-scale fog (hundreds of meters) particularly during summers is widely unconsidered. However, these events are important for the local vegetation and particularly for the biological soil crusts (BSC) that are widely distributed in this extreme ecosystem. Consequently, a case study in a typical fog oasis in the Pan de Azucar National Park was conducted to test the feasibility combining field measurements, drone profiling, remote sensing and numerical modeling (i) to investigate fog-type specific differences regarding dynamics, physical properties and formation, (ii) to test the applicability of remote sensing technology for fog monitoring based on existing low-resolution and a proposed new high-resolution product and (iii) to estimate the related fog water input to BSCs. Two types of fog were observed. The well-known fog/LST deck emerging from the Pacific Ocean with high water path and large spatial extent was the first type. Fog of the second type was patchier, small-scale and not necessarily connected to the LST over the ocean. Instead, fog formation of the second type was related to thermal breeze systems, which produced shallow clouds containing less water than those of type 1. In general, such small-scale fog events were not captured well by existing remote sensing products but could be detected with the proposed new high-resolution product which provided promising results. Both fog types were important water resources for the BSCs, with approximately 8% to 24% of the fog water flux available to the BSCs at the surface. The results indicated the feasibility of the proposed methods' pool to estimate the water budget of BSCs with a high spatial resolution in the future.