Potential methane emission from north-temperate lakes following ice melt
Potential methane emission from north-temperate lakes following ice melt
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DOI：
10.4319/lo.1996.41.5.0985
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发表时间：
1996-07
影响因子：
4.5
通讯作者：
Catherine M. Michmerhuizen;R. Striegl;M. E. McDonald
中科院分区：
文献类型：
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作者：
Catherine M. Michmerhuizen;R. Striegl;M. E. McDonald
甲烷是一种具有辐射活性的温室气体，在整个开放水域季节从湖泊排放到大气中。然而，每年的湖泊CH 4排放量计算完全从开放水域的测量，不包括春季冰融化的时间可能大大低估了湖泊CH 4源强度。我们估计了北方明尼苏达州和威斯康星州的19个湖泊在冰融化时的潜在春季CH 4排放。湖泊面积从2.7公顷到57 300公顷不等，沿岸的沉积物类型各不相同。回归分析表明，湖泊面积解释了相对未受干扰的湖泊的潜在CH 4排放的变异的38%，作为湖泊面积增加潜在的CH 4排放每单位面积减少。列入第二个任期占软有机丰富的滨海区沉积物的存在或不存在解释83%的潜在春季CH 4排放的方差。假定软沿岸的沉积物与硬沿岸的沉积物湖泊的比例为1：1，则明尼苏达州45°以北、面积≥4公顷的所有湖泊1993年春季的CH 4排放总量估计为1.5 x 10 8 mol CH 4。排放量估计值范围从5.3x10 - 7摩尔（假设没有湖泊有软质有机物丰富的沿岸的沉积物）到4.5x10 - 8摩尔（假设所有湖泊都有软质有机物丰富的沿岸的沉积物）不等。今年春季的CH 4脉冲可能占小型湖泊每年排放到大气中的CH 4的40%。
Methane, a radiatively active greenhouse gas, is emitted from lakes to the atmosphere throughout the open-water season. However, annual lake CH 4 emissions calculated solely from open-water measurements that exclude the time of spring ice melt may substantially underestimate the lake CH 4 source strength. We estimated potential spring CH 4 emission at the time of ice melt for 19 lakes in northern Minnesota and Wisconsin. Lakes ranged in area from 2.7 to 57,300 ha and varied in littoral zone sediment type. Regression analyses indicated that lake area explained 38% of the variance in potential CH 4 emission for relatively undisturbed lakes ; as lake area increases potential CH 4 emission per unit area decreases. Inclusion of a second term accounting for the presence or absence of soft organic-rich littoral-zone sediments explained 83% of the variance in potential spring CH 4 emission. Total estimated spring CH 4 emission for 1993 for all Minnesota lakes north of 45° with areas ≥4 ha was 1.5 x 10 8 mol CH 4 assuming a 1 : 1 ratio of soft littoral sediment to hard littoral sediment lakes. Emission estimates ranged from 5.3x10 7 mol assuming no lakes have soft organic-rich littoral sediments to 4.5 x 10 8 mol assuming all lakes have soft organic-rich littoral sediments. This spring CH 4 pulse may make up as much as 40% of the CH 4 annually emitted to the atmosphere by small lakes.