Northern lakes are considered a major source of atmospheric methane (CH₄), a potent GHG^1,2. However, large uncertainties in their emissions (7–26 Tg CH₄ yr^–1; ref. ²) arise from challenges in upscaling field data, including fluxes by ebullition (bubbling), the dominant emission pathway². Remote sensing of ebullition would allow detailed mapping of regional emissions but has hitherto not been developed. Here, we show that lake ebullition can be imaged using synthetic aperture radar remote sensing during ice-cover periods by exploiting the effect of ebullition on the texture of the ice–water interface. Applying this method to five Alaska regions and combining spatial remote sensing information with year-round bubble-trap flux measurements, we create ebullition-flux maps for 5,143 Alaskan lakes. Regional lake CH₄ emissions, based on satellite remote sensing analyses, were lower compared to previous estimates based on upscaling from individual lakes^2,3 and were consistent with independent airborne CH₄ observations. Thermokarst lakes formed by thaw of organic-rich permafrost had the highest fluxes, although lake density and lake size distributions also controlled regional emissions. This new remote sensing approach offers an opportunity to improve knowledge about Arctic CH₄ fluxes and helps to explain long-standing discrepancies between estimates of CH₄ emissions from atmospheric measurements and data upscaled from individual lakes.

北部湖泊被认为是大气甲烷（CH ₄）的主要来源，这是一种有力的GHG ^1,2。但是，其排放的不确定性很大（7–26 Tg CH ₄  yr ^–1；参考文献²）是由于现场数据的升级所带来的挑战，包括以磁通量（鼓泡）为主的排放途径²。遥感白化可以对区域排放物进行详细的制图，但迄今尚未开发。在这里，我们展示了利用冰盖作用对冰水界面纹理的影响，在合成冰覆盖期间，可以使用合成孔径雷达遥感对湖泊的冰盖作用进行成像。将这种方法应用于阿拉斯加的五个地区，并将空间遥感信息与全年的气泡阱通量测量值相结合，我们为5143个阿拉斯加湖泊创建了通量通量图。基于卫星遥感分析得出的区域性CH ₄排放低于先前基于各个湖泊^2,3的放大比例得出的估计值，并且与独立的机载CH ₄一致观察。尽管湖泊密度和湖泊大小分布也控制了区域排放，但是由富含有机物的多年冻土融化形成的热喀斯特湖的通量最高。这种新的遥感方法为提高对北极CH ₄通量的认识提供了机会，并有助于解释大气测量结果中的CH ₄排放估算值与各个湖泊的放大数据之间的长期差异。