• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Atmospheric chemistry and physics >Insights into the role of soot aerosols in cirrus cloud formation
【24h】

Insights into the role of soot aerosols in cirrus cloud formation

机译：深入了解烟尘气溶胶在卷云形成中的作用

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cirrus cloud formation is believed to be dominated by homogeneous freezingof supercooled liquid aerosols in many instances. Heterogeneous ice nucleisuch as mineral dust, metallic, and soot particles, and some crystallinesolids within partially soluble aerosols are suspected to modulate cirrusproperties. Among those, the role of ubiquitous soot particles is perhapsthe least understood. Because aviation is a major source of uppertropospheric soot particles, we put emphasis on ice formation in dispersingaircraft plumes. The effect of aircraft soot on cirrus formation in theabsence of contrails is highly complex and depends on a wide array ofemission and environmental parameters. We use a microphysical-chemical modelpredicting the formation of internally mixed, soot-containing particles up totwo days after emission, and suggest two principal scenarios: highconcentrations of original soot emissions could slightly increase the numberof ice crystals; low concentrations of particles originating from coagulationof emitted soot with background aerosols could lead to a significant reductionin ice crystal number. Both scenarios assume soot particles to be moderate icenuclei relative to cirrus formation by homogeneous freezing in the presence offew efficient dust ice nuclei. A critical discussion of laboratory experimentsreveals that the ice nucleation efficiency of soot particles depends stronglyon their source, and, by inference, on atmospheric aging processes. Mass andchemistry of soluble surface coatings appear to be crucial factors. Immersedsoot particles tend to be poor ice nuclei, some bare ones nucleate ice at lowsupersaturations. However, a fundamental understanding of these studies islacking, rendering extrapolations to atmospheric conditions speculative. Inparticular, we cannot yet decide which indirect aircraft effect scenario ismore plausible, and options suggested to mitigate the problem remain uncertain.
机译：在许多情况下，认为卷云的形成主要是过冷液态气溶胶的均匀冻结所致。怀疑是非均质的冰核，例如矿物粉尘，金属颗粒和烟灰颗粒，以及部分可溶的气溶胶中的某些结晶固体，可调节卷云特性。其中，普遍了解的烟灰颗粒的作用可能是最少了解的。因为航空是对流层上烟尘颗粒的主要来源，所以我们在分散飞机羽流时着重冰的形成。在没有凝结尾迹的情况下，航空煤烟对卷云形成的影响非常复杂，并取决于各种各样的排放和环境参数。我们使用微物理化学模型预测排放后两天内部混合的含碳烟颗粒的形成，并提出了两种主要情况：高浓度的原始碳烟排放可能会略微增加冰晶的数量;排放烟灰与背景气溶胶凝结而产生的低浓度颗粒可导致冰晶数量显着减少。两种情况均假设烟灰颗粒相对于通过形成有效的粉尘冰核均匀冻结而形成的卷云为中等的冰核。对实验室实验的严格讨论表明，烟尘颗粒的冰核效率主要取决于其来源，并据此推断取决于大气老化过程。可溶性表面涂层的质量和化学性质似乎是关键因素。浸没的煤烟颗粒往往是较弱的冰核，一些裸露的核则以低过饱和度使冰成核。但是，对这些研究缺乏基本的了解，从而推测了大气条件。特别是，我们尚无法确定哪种间接飞机影响情景更合理，建议减轻该问题的方案仍不确定。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号