Rain-fed pulses of methane from East Africa during 2018-2019 contributed to atmospheric growth rate
Rain-fed pulses of methane from East Africa during 2018-2019 contributed to atmospheric growth rate
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DOI：
10.1088/1748-9326/abd8fa
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发表时间：
2021-02-01
影响因子：
6.7
通讯作者：
Boesch, Hartmut
中科院分区：
文献类型：
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作者：
Lunt, Mark F.;Palmer, Paul, I;Boesch, Hartmut
东非是湿地甲烷（CH 4）排放的一个关键地点，这是由降雨量的变化驱动的，而降雨量的变化又受到印度洋海面温度梯度的影响。利用甲烷的卫星观测和大气化学传输模型，我们量化了2018年和2019年东非的甲烷排放量，当时在2018年的长降雨（3月至5月）和2019年的短降雨（12月至12月）期间存在3 σ异常降雨。这些降雨异常导致6.2 +/- 0.3 Tg CH 4和8.6 +/- 0.3 Tg CH 4的排放量，在每三个月期间，分别代表了10%和37%的增长相比，在相反的一年，当降雨量接近长期的季节平均值。我们发现，额外的短降雨排放量相当于2019年全球排放量增长的四分之一以上，这凸显了东非在全球甲烷预算中的不成比例的作用。
East Africa is a key location for wetland emissions of methane (CH4), driven by variations in rainfall that are in turn influenced by sea-surface temperature gradients over the Indian Ocean. Using satellite observations of CH4 and an atmospheric chemistry-transport model, we quantified East African CH4 emissions during 2018 and 2019 when there was 3-sigma anomalous rainfall during the long rains (March-May) in 2018 and the short rains (October-December) in 2019. These rainfall anomalies resulted in CH4 emissions of 6.2 +/- 0.3 Tg CH4 and 8.6 +/- 0.3 Tg CH4, in each three month period, respectively, and represent a 10% and 37% increase compared to the equivalent season in the opposite year, when rainfall was close to the long-term seasonal mean. We find the additional short rains emissions were equivalent to over a quarter of the growth in global emissions in 2019, highlighting the disproportionate role of East Africa in the global CH4 budget.