Organohalogen emissions from saline environments – spatial extrapolation using remote sensing as most promising tool
Organohalogen emissions from saline environments – spatial extrapolation using remote sensing as most promising tool
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DOI：
10.5194/bg-9-1225-2012
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发表时间：
2011-07
期刊：
影响因子：
4.9
通讯作者：
K. Kotte;F. Löw;Stefan G. Huber;T. Krause;I. Mulder;H. Schöler
中科院分区：
文献类型：
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作者：
K. Kotte;F. Löw;Stefan G. Huber;T. Krause;I. Mulder;H. Schöler
抽象。由于其负水收支，最近的半干旱/干旱地区的特点是大量蒸发（盐湖和咸土壤）。我们最近发现，这些高盐环境是大量挥发性卤代有机卤素（VOX）的额外来源。这些化合物可以影响平流层的臭氧层，并在气溶胶的产生中发挥关键作用。在南咸海盆地进行了遥感分析，提供了主要土壤类型及其范围和时空演变的信息。在干燥和潮湿的土壤样品中测定了24小时后的VOX产量。在高盐表土剖面中发现了几种C1-和C2有机卤素，包括CH 3Cl，CH 3Br，CHBr 3和CHCl 3。有机卤素的范围还包括反式-1，2-二氯乙烯（DCE），这是第一次在自然界中产生。使用中分辨率成像光谱仪时间序列和监督图像分类的每日生产率的DCE已计算为15 000平方公里的测距研究区在南部Aralkum。应用的实验室设置模拟气候条件的短期变化，从干燥的盐渍土开始，在降雨或洪水期间立即加湿。它描述了一般VOX生产潜力，但只允许粗略估计产生的排放量。由于咸海的退化，受盐影响的土壤面积正在扩大，预计未来VOX排放量将增加。讨论了基于卫星的快速变化检测和盐分类的机会、限制和要求。
Abstract. Due to their negative water budget most recent semi-/arid regions are characterized by vast evaporates (salt lakes and salty soils). We recently identified those hyper-saline environments as additional sources for a multitude of volatile halogenated organohalogens (VOX). These compounds can affect the ozone layer of the stratosphere and play a key role in the production of aerosols. A remote sensing based analysis was performed in the Southern Aral Sea basin, providing information of major soil types as well as their extent and spatial and temporal evolution. VOX production has been determined in dry and moist soil samples after 24 h. Several C1- and C2 organohalogens have been found in hyper-saline topsoil profiles, including CH3Cl, CH3Br, CHBr3 and CHCl3. The range of organohalogens also includes trans-1,2-dichloroethene (DCE), which is reported here to be produced naturally for the first time. Using MODIS time series and supervised image classification a daily production rate for DCE has been calculated for the 15 000 km2 ranging research area in the southern Aralkum. The applied laboratory setup simulates a short-term change in climatic conditions, starting from dried-out saline soil that is instantly humidified during rain events or flooding. It describes the general VOX production potential, but allows only for a rough estimation of resulting emission loads. VOX emissions are expected to increase in the future since the area of salt affected soils is expanding due to the regressing Aral Sea. Opportunities, limits and requirements of satellite based rapid change detection and salt classification are discussed.