Precise measurement of the atmospheric transparency for the cosmic ray energy calibration in the TA experiment

TA实验中宇宙线能量校准大气透明度的精确测量

基本信息

批准号：
18403004
负责人：
CHIKAWA Michiyuki
金额：
$ 10.68万
依托单位：
Kinki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

1. There are many experiments to measure the atmospheric properties, especially its transparency, in the field of meteolology, planet science, earth science, environmental science, biological and so on. The purposes of their experiments are really manifold and there are many theoretical models to explain. The atmosphere is consist of molecules of some chemical components and various aerosol, and has very important role for the weather condition and the thermal balance due to circulation in the troposphere.An atmospheric monitoring system has installed at Utah desert in the USA, to study the properties of atmosphere using a laser LIDAR(Light Detection And Ranging) system and an infra-red(IR) camera. Its original aim is to measure the atmospheric transparency for a cosmic rays experiment, the Telescope Array Experiment, which has many fluorescent light detectors. For this aim, the atmospheric extinction coefficient and the cloudiness should be determined precisely as possible, e.g. spati … More al resolution of less than 15m.2. What have done are ;(1) The LIDAR system consisits of a laser emitter and a light receiver with a photo multiplier tube(PMT) mounting on a steerable base. The laser emits pulse lights successively into the atmosphere and the receiver detects scattered faint lights by the PMT. To determine the atmospheric extinction coefficient, a large amount of data has been acquired using LIDAR system at the Utah desert commencing from July 2005. There are over 310,000 events data at the end of FY2007 and is analyzed by means of so-called the slope method and/or the Klett's method after due consideration of atmospheric pressure effect. A consistent result with a calculation of the Rayleigh scattering is obtained for the vertical extinction coefficient above an altitude of about ten kilometres in a calm weather. It is also found that the one-dimentional atmospheric density model is reasonable assumption within the accuracy of few percent uncertainty on a limitative condition in the Utah desert.(2) The LIDAR for LR site is still continued an R&D and shall expect to install in FY2008.(3) We can also suggests to distinguish the Rayleigh scattering (air molecular) component and the Mie(aerosol) scattering componet from the data analysis within several percents resolution comparing with a theoretical prediction.Also we have installed an infra-red camera at BRM site in March 2008 to measure cloud and/or water vapour component in the atmosphere. Less

1. 在气象学、行星科学、地球科学、环境科学、生物等领域有很多测量大气特性，特别是大气透明度的实验，其实验的目的非常多，并且有很多理论模型。解释一下。大气由一些化学成分的分子和各种气溶胶组成，由于对流层的环流，对天气状况和热平衡具有非常重要的作用。美国犹他州沙漠安装了大气监测系统，研究大气的特性激光雷达（光探测和测距）系统和红外（IR）相机的最初目的是测量宇宙射线实验的大气透明度，即望远镜阵列实验，为此目的有许多荧光探测器。，大气消光系数和云量应尽可能精确地确定，例如空间分辨率小于15m.2。激光发射器和安装在可操纵底座上的带有光电倍增管（PMT）的光接收器将激光连续发射到大气中，接收器通过 PMT 检测散射的微弱光来确定大气消光系数。从 2005 年 7 月开始，在犹他州沙漠使用 LIDAR 系统采集了 310,000 多个事件数据。截至 2007 财年末，有超过 310,000 个事件数据，并通过所谓的斜率法进行了分析和/或在适当考虑大气压力影响后的Klett方法对于在平静天气下大约10公里高度以上的垂直消光系数获得了与瑞利散射的计算一致的结果。 - 在犹他州沙漠的限制条件下，维度大气密度模型的准确性为百分之几的不确定性，是合理的假设。(2) LR 站点的 LIDAR 仍在继续研发，预计将安装在FY2008。(3) 我们还可以建议从数据分析中区分瑞利散射（空气分子）分量和米氏（气溶胶）散射分量，与理论预测相比，分辨率在几个百分点内。此外，我们还安装了红外摄像机2008 年 3 月在 BRM 现场测量大气中的云和/或水蒸气成分。