Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change
Analyzing cloud base at local and regional scales to understand tropical montane cloud forest vulnerability to climate change
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分析当地和区域尺度的云底，以了解热带山地云林对气候变化的脆弱性
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
M. Scholl
中科院分区：
文献类型：
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作者：
A. V. Beusekom;G. González;M. Scholl
摘要。云浸没在降雨之外提供水分、抑制蒸腾作用以及在无雨时期维持热带山地云雾林（tmcf）的程度尚不清楚。如果由于区域变暖或森林砍伐导致云基高度上升，气候和土地利用变化将对这些森林构成威胁。为了建立量化未来云底变化的基线，我们在TMCF逆风的森林海拔100 m处安装了一个ceilometer，该森林海拔范围从~ 600 m到1,100 m，位于波多黎各东部的Luquillo山脉。利用机场自动地面观测系统（ASOS）的高度计数据、无线电探空数据以及云气溶胶激光雷达和红外探路者卫星观测（CALIPSO）的卫星数据，研究了加勒比海周边地区的季节性云基动态、信风逆温（TWI）高度和典型云厚度。山区附近的云基很少被量化，所以这些结果代表了对TMCF的季节和日云基动态的第一次观察。2013年5月至2016年8月，盛夏旱季云基最低，冬季旱季云基低于山顶的频率与雨季相同。最低云底最常出现在海拔600 m以上，740 ~ 964 m。Luquillo森林的低云基础高度比加勒比地区的其他六个站点高约200-600 m，突出了站点选择对测量地形对云高度的影响的重要性。靠近海洋云系统，其中浅积云在高度和覆盖上是季节性不变的，加上当地信风地形抬升和云的形成，可以解释旱季低云的形成。结果表明，气候变化对低海拔TMCFs的威胁不仅限于旱季；天气尺度天气模式的变化增加了雨季（云底较高的时期）干旱期的频率，也可能影响生态系统的健康。
Abstract. The degree to which cloud immersion provides water in addition to rainfall, suppresses transpiration, and sustains tropical montane cloud forests (TMCFs) during rainless periods is not well understood. Climate and land use changes represent a threat to these forests if cloud base altitude rises as a result of regional warming or deforestation. To establish a baseline for quantifying future changes in cloud base, we installed a ceilometer at 100 m altitude in the forest upwind of the TMCF that occupies an altitude range from ∼ 600 m to the peaks at 1100 m in the Luquillo Mountains of eastern Puerto Rico. Airport Automated Surface Observing System (ASOS) ceilometer data, radiosonde data, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite data were obtained to investigate seasonal cloud base dynamics, altitude of the trade-wind inversion (TWI), and typical cloud thickness for the surrounding Caribbean region. Cloud base is rarely quantified near mountains, so these results represent a first look at seasonal and diurnal cloud base dynamics for the TMCF. From May 2013 to August 2016, cloud base was lowest during the midsummer dry season, and cloud bases were lower than the mountaintops as often in the winter dry season as in the wet seasons. The lowest cloud bases most frequently occurred at higher elevation than 600 m, from 740 to 964 m. The Luquillo forest low cloud base altitudes were higher than six other sites in the Caribbean by ∼ 200–600 m, highlighting the importance of site selection to measure topographic influence on cloud height. Proximity to the oceanic cloud system where shallow cumulus clouds are seasonally invariant in altitude and cover, along with local trade-wind orographic lifting and cloud formation, may explain the dry season low clouds. The results indicate that climate change threats to low-elevation TMCFs are not limited to the dry season; changes in synoptic-scale weather patterns that increase frequency of drought periods during the wet seasons (periods of higher cloud base) may also impact ecosystem health.
使用统计方法从 MODIS（集合 051）白天数据检测山区地面雾
影响因子：
3.8
作者：
Schulz;Bendix
通讯作者：
Bendix