Dada Lubna, Okuljar Magdalena, Shen Jiali, Olin Miska, Wu Yusheng, Heimsch Laura, Herlin Ilkka, Kankaanrinta Saara, Lampimäki Markus, Kalliokoski Joni, Baalbaki Rima, Lohila Annalea, Petäjä Tuukka, Maso Miikka Dal, Duplissy Jonathan, Kerminen Veli-Matti, Kulmala Markku
Institute for Atmospheric and Earth System Research, University of Helsinki PO Box 64, 00014 Finland
Laboratory of Atmospheric Chemistry, Paul Scherrer Institute 5232 Villigen Switzerland.
Environ Sci Atmos. 2023 Jul 7;3(8):1195-1211. doi: 10.1039/d3ea00065f. eCollection 2023 Aug 10.
Agriculture provides people with food, but poses environmental challenges. comprehensive observations on an agricultural land at Qvidja in Southern Finland, we were able to show that soil-emitted compounds (mainly ammonia and amines), together with available sulfuric acid, form new aerosol particles which then grow to climate-relevant sizes by the condensation of extremely low volatile organic compounds originating from a side production of photosynthesis (compounds emitted by ground and surrounding vegetation). We found that intensive local clustering events, with particle formation rates at 3 nm about 5-10 times higher than typical rates in boreal forest environments, occur on around 30% of all days. The requirements for these clustering events to occur were found to be clear sky, a low wind speed to accumulate the emissions from local agricultural land, particularly ammonia, the presence of low volatile organic compounds, and sufficient gaseous sulfuric acid. The local clustering will then contribute to regional new particle formation. Since the agricultural land is much more effective per surface area than the boreal forest in producing aerosol particles, these findings provide insight into the participation of agricultural lands in climatic cooling, counteracting the climatic warming effects of farming.
农业为人们提供食物，但也带来了环境挑战。通过对芬兰南部奎维贾一块农田的全面观测，我们能够证明，土壤排放的化合物（主要是氨和胺）与可用硫酸一起，形成新的气溶胶颗粒，这些颗粒随后通过光合作用副产物中极低挥发性有机化合物（地面和周围植被排放的化合物）的凝结，生长到与气候相关的尺寸。我们发现，在大约30%的日子里会发生强烈的局部聚集事件，3纳米处的颗粒形成速率比北方森林环境中的典型速率高约5至10倍。这些聚集事件发生的条件是晴空、低风速以积累当地农田的排放物，特别是氨、低挥发性有机化合物的存在以及足够的气态硫酸。然后，局部聚集将有助于区域新颗粒的形成。由于农田每单位表面积在产生气溶胶颗粒方面比北方森林更有效，这些发现为农田参与气候降温、抵消农业的气候变暖效应提供了见解。
