Experimental study on the micro-physical process of ozone-hole depression by ice crystals in PSC

PSC中冰晶抑制臭氧空洞微物理过程的实验研究

• 批准号: 05455001
• 负责人: FURUKAWA Yoshinori
• 金额: $ 3.14万
• 依托单位: HOKKAIDO 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: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05455001/
• 关键词: Ozone hole; Polar stratosheric cloud; Ice crystals; Ellipsometry; Second harmonic generation; Molecular dynamics simulation; Surface transition layr; Fluorocarbon; フロンガス; 氷結晶; 表面構造; 表面融解; 極成層圏雲; オゾン層

1. Ozone-hole depression in the stratospheric atmosphere is enhanced by the ice crystals which are formed in the Polar Stratospheric Cloud (PSC). In order to measure the decomposition rate of ozone molecules on the ice crystal surfaces, an experiment was carried out using a newly developed chamber, which was combine with the optical detectors for the ice surface structures, such as an ellipsometer and a Surface Second Harmonic Generation (SSHG). specially, the SSH signal was first detected from the ice crystal surface, which was prepared by the negative-crystal method and molecularly flat. As a result, we claim that it was made possible to carry out the quantitative measurements for the decomposition rate of ozone molecules on the ice crystal surfaces.2. The physical process of the decomposition of ozone molecules on the ice crystal surfaces relates to the ice surface structures in molecular-level. A molecular dynamics simnlation for the ice surface was carried out in the wide temperature range. As a result, a thin transition layr with the disordered arrangement of water molecules was detected. Water molecules in such the transition layr may react to the HCl or CIONO_2 molecules, which are formed by the decomposition of fluorocarbon molecules in the stratosheric atmosphere. On the other hand, the molecular dynamics simulation for the ice/water (namely, ice/transition layr) interface also was carried out and we found the anisotropic properties for the difference of crystallographic orientations. This result means that the activity of ice crystals for the decomposition of ozone molecules may depend on the ice crystal shape.

1.极地平流层云（PSC）中形成的冰晶增强了平流层大气中的臭氧空洞低压。为了测量臭氧分子在冰晶表面的分解速率，利用一种新研制的臭氧分解室，将椭圆偏振仪和表面二次谐波发生器（SSHG）等用于探测冰晶表面结构的光学探测器与臭氧分解室联合收割机相结合，进行了臭氧分子在冰晶表面分解速率的测量。特别地，SSH信号首次从冰晶表面检测到，该冰晶表面是通过负晶体法制备的并且分子平坦。因此，我们声称，这是有可能进行定量测量臭氧分子在冰晶表面的分解率.臭氧分子在冰晶表面分解的物理过程与冰晶表面的分子结构有关。在较宽的温度范围内对冰面进行了分子动力学模拟。结果，检测到水分子无序排列的薄过渡层。过渡层中的水分子可能与平流层大气中氟碳化合物分解生成的HCl或ClONO_2分子发生反应。另一方面，对冰/水（即冰/过渡层）界面进行了分子动力学模拟，发现了由于晶体取向的不同而引起的各向异性。这一结果意味着冰晶分解臭氧分子的活性可能取决于冰晶的形状。

项目成果

Y.Furukawa: "Temperature dependence of the growth form of negative crystal in an ice single crystal and evaporation kinetics for its surface" J.Crystal Growth. 129. 571-581 (1993)

Y.Furukawa：“冰单晶中负晶体生长形式的温度依赖性及其表面蒸发动力学”J.Crystal Growth。

Y.Furukawa, H.Nada, T.Ishizaki: "Sturucture and dynamicproperties of transition layrs at surface and interfaces of ice crystals" J.Jpn Assoc.Cryst.Growth. 21 (in Japanese). S521-S528 (1994)

Y.Furukawa、H.Nada、T.Ishizaki：“冰晶表面和界面过渡层的结构和动态特性”J.Jpn Assoc.Cryst.Growth。

Y.Furukawa: "Direct evidence for melting transition at interface between ice crystal and glass substrate" J.Crystal Growth. 128. 1137-1142 (1993)

Y.Furukawa：“冰晶和玻璃基板之间界面熔化转变的直接证据”J.Crystal Growth。

H.Nada: "Arisotropic Properties of Ice/water Interface:A Molecular Dynamics Study" Jpn.J.Appl.Phy.34. 583-588 (1995)

H.Nada：“冰/水界面的各向异性特性：分子动力学研究”Jpn.J.Appl.Phy.34。

Yoshinori Furukawa,Shigetsugu Kohata: "Temperature dependence of the growth form of negative crystal in an ice sigle crystal and evaporation kinetics for its surface" Journal of Crystal Growth. 129. 571-581 (1993)

Yoshinori Furukawa、Shigetsugu Kohata：“冰单晶体中负晶体生长形式的温度依赖性及其表面的蒸发动力学”《晶体生长杂志》。