DOI: 10.1002/jgrd.50517
论文题名: A new theoretical method for calculating temperature and water vapor saturation ratio in an expansion cloud chamber
作者: Moteki N. ; Kondo Y.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 12 起始页码: 6633
结束页码: 6642
语种: 英语
英文关键词: Atmospheric thermodynamics
; cloud physics
; expansion chamber
; supersaturation
Scopus关键词: Atmospheric thermodynamics
; Differential equations
; Measurement errors
; Precipitation (meteorology)
; Supersaturation
; Thermodynamic properties
; Water vapor
; Classical thermodynamics
; Cloud physics
; Expansion chamber
; Finite time resolution
; Quantitative interpretation
; Theoretical calculations
; Time evolution equations
; Time-dependent temperature
; Cloud chambers
; aerosol
; air temperature
; cloud microphysics
; condensation
; droplet
; experimental study
; graphical method
; theoretical study
; thermodynamics
; time dependent behavior
; water vapor
英文摘要: The expansion cloud chamber is a widely used apparatus for investigating the dynamics of condensational growth of aerosols and clouds. Theoretical calculations of temperature T and water vapor saturation ratio S are necessary for quantitative interpretations of experimental data obtained from the expansion cloud chamber. In this paper, we revisit the thermodynamics associated with the underlying assumptions for calculating the time-dependent temperature T(t) and saturation ratio S(t) in an expansion chamber as a function of experimentally observable parameters. We introduce an intuitive and robust method, the virtual path (VP) method, by which changes in the thermodynamic state of a moist air parcel containing cloud droplets are schematically represented on a thermodynamic diagram. The validity of the VP method is confirmed by comparisons with the differential equation (DE) method, which is a numerical simulation of real physical processes according to the time evolution equations involving T and S. In contrast to the conventional DE method, the governing equations of the VP method do not involve time t, an irrelevant parameter in the framework of classical thermodynamics. The VP method is advantageous compared to the DE method because the former is applicable to the raw experimental data acquired with a finite time resolution, allowing a robust calculation of the T and S values and the errors that are only caused by the measurement errors of the input data. Key Points The exact and comprehensive thermodynamic theory for an expansion cloud chamber A new intuitive and robust method for calculating water vapor saturation ratio Graphical analysis of moist air under super/subsaturated conditions © 2013. American Geophysical Union. All Rights Reserved. 资助项目: 23221001
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63656
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
Recommended Citation:
Moteki N.,Kondo Y.. A new theoretical method for calculating temperature and water vapor saturation ratio in an expansion cloud chamber[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(12)