Development of the evaluation technique on diffusion coefficient of snowpack for carbon dioxide using acoustical property

利用声学特性评价积雪二氧化碳扩散系数技术的开发

• 批准号: 17540421
• 负责人: KOMINAMI Yasuhiro
• 金额: $ 2.02万
• 依托单位: National Agricultural Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17540421/
• 关键词: carbon dioxide; snowpack; sound velocity; acoustic attenuation coefficient; gas diffusivity; CO2; フラックス; 音響; 透過係数; 減衰係数; CO_2; 溶存二酸化炭素; PCO_2

1. Sound velocity and the acoustic attenuation coefficient of the snowpack of various snow conditions were measured, and relation between physical properties of snow and acoustical property were examined. The sound source used are sine wave from 200Hz to 8000Hz every 1/3 octaves.(1) The sound velocity of the air of the snowpack depends on the winding level of the diffusion mute just like the gas diffusion coefficient. However it has been understood that the sound passes the beeline in the winding space while the gas diffusion coefficient depends on the mean distance of the winding space.(2) The acoustic attenuation coefficient that spread in the space air was in inverse proportion to the square of the space sire, and it was confirmed that it was a phenomenon similar to the attenuation of the mass flow in the space caused by the pressure fluctuation. And the acoustic attenuation coefficient of the uniting snow particles is in inverse proportion to the snow density, and guessed to be the one by the mechanism of the interception by the effect of mass to the damping coefficient of the spreading sound.2. The carbon dioxide concentration was continuously measured in three depth of the natural snowfall, and the phenomenon of the gas diffusivity of the appearance of the snow in the vicinity of the surface increasing by the wind was confirmed. From the above result, the sound velocity and the acoustic attenuation coefficient of the snowpack are related to the character to decide the gaseous environment of the snowpack..

1、测量了各种雪况下积雪的声速和声衰减系数，考察了雪的物理特性与声学特性之间的关系。使用的声源是200Hz到8000Hz每1/3倍频程的正弦波。 (1)积雪空气的声速取决于扩散静音器的缠绕水平，就像气体扩散系数一样。然而，人们知道，声音在蜿蜒空间中沿直线传播，而气体扩散系数取决于蜿蜒空间的平均距离。（2）在空间空气中传播的声衰减系数与平方成反比。空间君王的气息，被证实是一种类似于压力波动导致空间内质量流量衰减的现象。联合雪粒的声衰减系数与雪的密度成反比，推测是通过质量对传播声阻尼系数的影响而拦截的机理。 2．在自然降雪的三个深度处连续测量二氧化碳浓度，并证实了雪表面附近的气体扩散率因风而增加的现象。由以上结果可知，积雪的声速和声衰减系数与决定积雪气体环境的特性有关。

项目成果

The role of seasonal snow cover on carbon dioxide cycle.

季节性积雪对二氧化碳循环的作用。

• 发表时间: 2006
• 期刊: Applied Meteorology and Climate Resources 19
• 作者: KOMINAMI;Y.
• 通讯作者: Y.

Relation between acoustic attenuation coefficient and characteristic of snow.

声衰减系数与雪特性的关系。

• 发表时间: 2008
• 作者: KOMINAMI;Y.;YOKOYAMA;Y.
• 通讯作者: Y.

Measurement of Dissolved Carbon dioxide in Runoff of Snow Melt Water(2).

雪融水径流中溶解二氧化碳的测量(2)。

• 发表时间: 2006
• 作者: KOMINAMI;Y.;YOKOYAMA;K.
• 通讯作者: K.

Measurement of Sound Velocity in Deposited Snow.

沉积雪中声速的测量。

• 发表时间: 2008
• 作者: KOMINAMI;Y.;YOKOYAMA;Y.
• 通讯作者: Y.

安価なCO2センサーを大気中のフラックス測定に使ってみた

我尝试使用廉价的二氧化碳传感器来测量大气通量。

• 发表时间: 2007
• 作者: KOMINAMI;Y.;YOKOYAMA;Y.;小南靖弘
• 通讯作者: 小南靖弘