Einbock Annika, Burtscher Emma, Frey Claudia, Conen Franz
Department of Environmental Sciences, University of Basel, Bernoullistrasse 30, 4056 Basel Switzerland.
R Soc Open Sci. 2023 Feb 8;10(2):220878. doi: 10.1098/rsos.220878. eCollection 2023 Feb.
We examined ice-nucleating particles (INPs) in the plumes of the Tocantins and Amazon rivers, which drain watersheds with different proportions of degraded land. The concentration of INPs active at -15°C (INP) was an order of magnitude lower in the Tocantins (mean = 13.2 ml; s.d. = 7.8 ml), draining the more degraded watershed, compared with the Amazon (mean = 175.8 ml; s.d. = 11.2 ml), where the concentration was also significantly higher than in Atlantic surface waters (mean = 3.2 ml; s.d. = 2.3 ml). Differences in heat tolerance suggest that INPs emitted by the Amazon rainforest to the atmosphere or washed into the river might originate from contrasting sources on top of and below the rainforest canopy, respectively. For the Amazon River, we estimate a daily discharge of 10 INP to Atlantic waters. Rivers in cooler climate zones tend to have much higher concentrations of INPs and could, despite a smaller water volume discharged, transfer even larger absolute numbers of INP to shelf waters than does the Amazon. To what extent these terrestrial INPs become aerosolized by breaking waves and bubble-bursting remains an open question.
我们研究了托坎廷斯河和亚马逊河羽流中的冰核粒子（INPs），这两条河流经不同比例退化土地的流域。与亚马逊河（平均值 = 175.8毫升；标准差 = 11.2毫升）相比，流经退化程度更高流域的托坎廷斯河在-15°C时活跃的冰核粒子（INP）浓度低一个数量级（平均值 = 13.2毫升；标准差 = 7.8毫升），亚马逊河的浓度也显著高于大西洋表层水（平均值 = 3.2毫升；标准差 = 2.3毫升）。耐热性的差异表明，亚马逊雨林排放到大气中或冲入河流的冰核粒子可能分别来自雨林冠层之上和之下的不同来源。对于亚马逊河，我们估计每天有10个冰核粒子排放到大西洋水域。气候较凉爽地区的河流往往含有更高浓度的冰核粒子，尽管其排水量较小，但与亚马逊河相比，它们向陆架水域输送的冰核粒子绝对数量可能更大。这些陆地冰核粒子在多大程度上因海浪破碎和气泡破裂而雾化仍是一个悬而未决的问题。
