Irreversible loss of ice nucleation active sites in mineral dust particles caused by sulphuric acid condensation
Irreversible loss of ice nucleation active sites in mineral dust particles caused by sulphuric acid condensation
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硫酸凝结导致矿物尘埃颗粒中冰核活性位点不可逆损失
DOI：
10.5194/acp-10-11471-2010
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发表时间：
2010
影响因子：
6.3
通讯作者：
B. Sierau
中科院分区：
文献类型：
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作者：
R. Sullivan;M. Petters;P. DeMott;S. Kreidenweis;H. Wex;D. Niedermeier;S. Hartmann;T. Clauss;F. Stratmann;P. Reitz;J. Schneider;B. Sierau
抽象的。在FROST-2（FReezing的灰尘）在莱比锡气溶胶云相互作用模拟器（LACIS）进行的测量活动，我们调查了300纳米亚利桑那州测试灰尘矿物颗粒的冰成核性能的变化热化学处理后，通过不同的量和组合的暴露于硫酸蒸汽，氨气，水蒸汽和热量。使用科罗拉多州立大学的连续流扩散室，在-30 °C和-25 °C的水亚饱和和过饱和湿度状态下测定了经处理的颗粒的非均质冰成核特性。通过气溶胶质谱仪和CCN衍生的吸湿性测量来估计硫酸涂层材料的量。硫酸的冷凝降低了粉尘颗粒的冰核能力，与硫酸的加入量成比例。在250 °C的热扩散器中加热涂覆的颗粒-旨在蒸发硫酸涂层-进一步降低了它们的冷冻能力。我们把这种行为归因于冰的活性表面位点被热加速的酸消化。将硫酸涂层粉尘暴露于氨气产生的颗粒具有同样差的冻结潜力;然而，在热扩散器中加热后，它们的冰成核能力的一部分可以恢复。在任何情况下，热化学处理的任何组合与未处理的粉尘相比，都没有增加涂覆的矿物粉尘颗粒的冰成核能力。这些第一次测量的影响相同的化学处理的尘埃粒子对他们的冰成核能力在水的亚饱和和混合相过饱和云的条件下显示，冰成核是更敏感的所有涂层处理在水的亚饱和制度。结果清楚地表明，在这两个制度后，浓缩硫酸冷凝的冰成核活性的不可逆损害。这意味着硫酸涂层引起冰活性表面位点的永久性化学和/或物理改性;液滴活化期间涂层的可能溶解没有恢复所有浸没/冷凝-冷冻能力。
Abstract. During the FROST-2 (FReezing Of duST) measurement campaign conducted at the Leipzig Aerosol Cloud Interaction Simulator (LACIS), we investigated changes in the ice nucleation properties of 300 nm Arizona Test Dust mineral particles following thermochemical processing by varying amounts and combinations of exposure to sulphuric acid vapour, ammonia gas, water vapour, and heat. The processed particles' heterogeneous ice nucleation properties were determined in both the water subsaturated and supersaturated humidity regimes at −30 °C and −25 °C using Colorado State University's continuous flow diffusion chamber. The amount of sulphuric acid coating material was estimated by an aerosol mass spectrometer and from CCN-derived hygroscopicity measurements. The condensation of sulphuric acid decreased the dust particles' ice nucleation ability in proportion to the amount of sulphuric acid added. Heating the coated particles in a thermodenuder at 250 °C – intended to evaporate the sulphuric acid coating – reduced their freezing ability even further. We attribute this behaviour to accelerated acid digestion of ice active surface sites by heat. Exposing sulphuric acid coated dust to ammonia gas produced particles with similarly poor freezing potential; however a portion of their ice nucleation ability could be restored after heating in the thermodenuder. In no case did any combination of thermochemical treatments increase the ice nucleation ability of the coated mineral dust particles compared to unprocessed dust. These first measurements of the effect of identical chemical processing of dust particles on their ice nucleation ability under both water subsaturated and mixed-phase supersaturated cloud conditions revealed that ice nucleation was more sensitive to all coating treatments in the water subsaturated regime. The results clearly indicate irreversible impairment of ice nucleation activity in both regimes after condensation of concentrated sulphuric acid. This implies that the sulphuric acid coating caused permanent chemical and/or physical modification of the ice active surface sites; the possible dissolution of the coating during droplet activation did not restore all immersion/condensation-freezing ability.
影响因子：
5.2
作者：
M. Eastwood;S. Cremel;Michael B. Wheeler;B. Murray;É. Girard;A. Bertram
通讯作者：
M. Eastwood;S. Cremel;Michael B. Wheeler;B. Murray;É. Girard;A. Bertram
影响因子：
6.3
作者：
通讯作者：
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