Do stratospheric aerosol droplets freeze above the ice frost point
Do stratospheric aerosol droplets freeze above the ice frost point
复制标题
平流层气溶胶液滴会在冰霜点以上冻结吗
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
T. Peter
中科院分区：
文献类型：
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作者：
T. Koop;U. Biermann;W. Raber;B. Luo;P. Crutzen;T. Peter
实验室实验表明，液态平流层气溶胶滴极地冬季条件下不冻结的温度高于水冰饱和温度（霜点）。量热测量冻结过冷H2SO 4/HNO 3/H2O散装溶液的浓度典型的极地平流层气溶胶表现出非常小的冻结率，这排除了均匀冻结的液滴的温度高于冰点的可能性。即使在这些温度下H2SO 4和HNO 3水合物的非均相形成也是一个非常低效的过程，除非平流层提供比实验室实验中存在的更适合成核的核，这似乎是不可能的。只有冰被发现是适合水合物形成的潜在核，这可能导致水合物在冰点以下的温度下冻结。
Laboratory experiments are presented which show that liquid stratospheric aerosol droplets under polar winter conditions do not freeze for temperatures higher than the water ice saturation temperature (frost point). Calorimetric measurements of the freezing of supercooled H2SO4/HNO3/H2O bulk solutions with concentrations typical of the polar stratospheric aerosol exhibit very small freezing rates, which excludes the possibility of homogeneous freezing of the droplets for temperatures above the frost point. Even heterogeneous formation of H2SO4 and HNO3 hydrates at these temperatures is a very inefficient process unless the stratosphere offers nuclei better suited for nucleation than those present in the laboratory experiments, which appears to be unlikely. Only ice was found to be a potential nucleus suited for the formation of the hydrates, which could cause the hydrates to freeze at temperatures below the frost point.