Experimental Study on Formation Process of Ice Particles in Stratospheric Clouds

平流层云中冰粒形成过程的实验研究

基本信息

批准号：
06452086
负责人：
ISHIZAKA Yutaka
金额：
$ 0.83万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06452086/
关键词：
Stratospheric clouds Freezing of acid droplets NAT particles Sulfuric acid droplets Freezing nuclei Ozone depletion Nitric acid 凍結核成層圏氷晶の凍結核酸性水滴の凍結温度成層圏雲粒子

项目摘要

Freezing points of acid droplets were measured in a cryostat under the stratospheric condition and chemical composition of ice particles formed in a cryostat was determined with an electron microscope using thin-film chemical methods. Acid droplets were suspended on the tungsten wires in the sample holder. Size range of the acid droplets was from 10 to 50 mum in diameter. Sulfuric acid, nitric acid, hydrochloric acid and methanesulfonic acid solutions were used to make acid droplets. Droplets were observed with a CCD camera through the microscope. Freezing temperature of droplets was determined by detecting ice embryos in the droplet. It was found from the experiment that freezing point of sulfuric acid droplets decreased linearly with increasing acid concentration. Freezing point of sulfuric acid droplets with acid concentration of 70%wt was about -80ﾟC.Freezing point of nitric acid droplets did not depend strongly on acid concertration, and it was lower than that of sulfuric acid droplets above 35%wt of acid concentration. Hydrochloric acid droplets froze at lower temperatures than freezing points of sulfuric acid and nitric acid droplets. On the other hand, melting points of ice particles were also measured by increasing temperatures of ice particles after acid droplets froze. Further, some of particles before and after freezing of sulfuric acid particles under the supply of nitric acid and water vapor were sampled on an electron microscope mesh covered with barium chloride and nitron films. NO3- ion was not detected in acid droplets, but it was detected in ice particles. The result indicates that nitric acid vapor can be absorbed in ice particles during their growth after acid droplets froze.The results of this laboratory experiments strongly suggests that ice and NAT particles can be formed by freezing of sulfuric acid particles in the stratosphere.

在平流层条件下在低温恒温器中测量酸滴的凝固点，并使用薄膜化学方法用电子显微镜测定低温恒温器中形成的冰粒的化学成分。酸滴悬浮在样品架中的钨丝上。酸滴的尺寸范围为直径10至50μm，使用硫酸、硝酸、盐酸和甲磺酸溶液来制备酸滴。通过显微镜观察液滴的冰点，通过检测液滴中的冰胚，发现硫酸液滴的冰点随着酸浓度的增加而线性降低。酸浓度为70%wt的液滴约为-80℃。硝酸液滴的凝固点不依赖于酸浓度，比硝酸液滴的凝固点低。酸浓度高于 35%wt 的硫酸滴在比硫酸和硝酸滴的冰点更低的温度下冻结。另一方面，还通过酸后升高冰粒的温度来测量冰粒的熔点。此外，在覆盖有钡的电子显微镜网上对硫酸颗粒在供给硝酸和水蒸气的情况下冻结之前和之后的一些颗粒进行取样。酸滴中未检测到氯离子和硝基离子，但在冰粒中检测到了NO3-离子。结果表明，酸滴冻结后，冰粒在生长过程中会吸收硝酸蒸气。强烈表明冰和 NAT 颗粒可以通过平流层中的硫酸颗粒冻结而形成。