Spatial and Temporal Patterns in Atmospheric Deposition of Dissolved Organic Carbon
Spatial and Temporal Patterns in Atmospheric Deposition of Dissolved Organic Carbon
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DOI：
10.1029/2022gb007393
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发表时间：
2022-10
影响因子：
5.2
通讯作者：
D. Liptzin;J. Boy;J. Campbell;N. Clarke;J. Laclau;R. Godoy;S. Johnson;K. Kaiser;G. Likens;G. P. Karlsson;D. Markewitz;M. Rogora;S. Sebestyen;J. Shanley;E. Vanguelova;A. Verstraeten;W. Wilcke;F. Worrall;W. McDowell
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作者：
D. Liptzin;J. Boy;J. Campbell;N. Clarke;J. Laclau;R. Godoy;S. Johnson;K. Kaiser;G. Likens;G. P. Karlsson;D. Markewitz;M. Rogora;S. Sebestyen;J. Shanley;E. Vanguelova;A. Verstraeten;W. Wilcke;F. Worrall;W. McDowell
溶解有机碳（DOC）在陆地生态系统中的大气沉降是全球碳循环中一个很小的组成部分，但研究很少。挥发性有机化合物（VOC）和有机颗粒物的排放是大气碳的来源，沉积是大气中有机碳去除的主要途径。在这里，我们评估DOC沉积的空间和时间模式，使用70个数据集，至少一年的长度范围从南纬40°到北纬66°。在全球范围内，整体沉积物中DOC浓度的中位数为1.7 mg L−1。DOC浓度在热带（25°）纬度显著较高。DOC沉积显着较高的热带地区，因为较高的DOC浓度和降水。使用全球中位数或纬度特定DOC浓度，计算出的全球沉积量分别为202或295 Tg C yr-1。许多网站表现出DOC浓度的季节性变化。在温带地区，DOC浓度较高，在生长季节，在热带地区，DOC浓度较高，在旱季。在34个长期（>10年）数据集中，有13个数据显示DOC浓度随时间显著下降，其他数据则无显著变化。基于有机碳的各种来源的大气中的大小和时间，生物源VOCs可能解释的纬度模式和季节性模式在温带纬度，而人为排放量的减少是最有可能的解释DOC浓度的下降。
Atmospheric deposition of dissolved organic carbon (DOC) to terrestrial ecosystems is a small, but rarely studied component of the global carbon (C) cycle. Emissions of volatile organic compounds (VOC) and organic particulates are the sources of atmospheric C and deposition represents a major pathway for the removal of organic C from the atmosphere. Here, we evaluate the spatial and temporal patterns of DOC deposition using 70 data sets at least one year in length ranging from 40° south to 66° north latitude. Globally, the median DOC concentration in bulk deposition was 1.7 mg L−1. The DOC concentrations were significantly higher in tropical (25°) latitudes. DOC deposition was significantly higher in the tropics because of both higher DOC concentrations and precipitation. Using the global median or latitudinal specific DOC concentrations leads to a calculated global deposition of 202 or 295 Tg C yr−1 respectively. Many sites exhibited seasonal variability in DOC concentration. At temperate sites, DOC concentrations were higher during the growing season; at tropical sites, DOC concentrations were higher during the dry season. Thirteen of the thirty‐four long‐term (>10 years) data sets showed significant declines in DOC concentration over time with the others showing no significant change. Based on the magnitude and timing of the various sources of organic C to the atmosphere, biogenic VOCs likely explain the latitudinal pattern and the seasonal pattern at temperate latitudes while decreases in anthropogenic emissions are the most likely explanation for the declines in DOC concentration.