Department of Thematic Studies - Environmental Change, Linköping University, Mäster Mattias väg, Linköping 58183, Sweden.
Department of Ecology, Evolution and Marine Biology, University of California, UCEN Rd, Santa Barbara, California 93117, United States.
Environ Sci Technol. 2023 Jun 13;57(23):8578-8587. doi: 10.1021/acs.est.2c09230. Epub 2023 May 30.
Large greenhouse gas emissions occur via the release of carbon dioxide (CO) and methane (CH) from the surface layer of lakes. Such emissions are modeled from the air-water gas concentration gradient and the gas transfer velocity (). The links between and the physical properties of the gas and water have led to the development of methods to convert between gases through Schmidt number normalization. However, recent observations have found that such normalization of apparent estimates from field measurements can yield different results for CH and CO. We estimated for CO and CH from measurements of concentration gradients and fluxes in four contrasting lakes and found consistently higher (on an average 1.7 times) normalized apparent values for CO than CH. From these results, we infer that several gas-specific factors, including chemical and biological processes within the water surface microlayer, can influence apparent estimates. We highlight the importance of accurately measuring relevant air-water gas concentration gradients and considering gas-specific processes when estimating .
大量温室气体排放是通过湖泊表层释放二氧化碳（CO）和甲烷（CH）而产生的。这些排放是通过空气-水气体浓度梯度和气体转移速度（）来模拟的。和气体与水的物理性质之间的联系，导致了通过施密特数归一化将气体之间的转换的方法的发展。然而，最近的观测结果发现，这种对来自实地测量的表观值的归一化估计，对于 CH 和 CO 可能会产生不同的结果。我们从四个对比湖泊的浓度梯度和通量测量中估计了 CO 和 CH 的值，发现 CO 的归一化表观值始终高于 CH（平均高 1.7 倍）。根据这些结果，我们推断，包括水面微层内的化学和生物过程在内的几个特定气体的因素，可能会影响表观值的估计。我们强调了在估计时准确测量相关的空气-水气体浓度梯度和考虑气体特异性过程的重要性。
