论文标题
Chajnantor地区的PWV测量二十年
Twenty years of PWV measurements in the Chajnantor Area
论文作者
论文摘要
语境。由于其良好的大气条件，人们对使用Chajnantor区域用于毫米和亚毫米天文学的兴趣正在增加。了解可降水蒸气（PWV）的一般地点年度变异性可以促进该地区新的观测值的规划。目标。我们寻求使用单个常见的物理单位为北部智利的Chajnantor地区创建一个20年的大气数据库（1997-2017），PWV。我们计划在Chajnantor Plateau和Cerro Chajnantor峰会之间提取天气关系，以评估更高位置的望远镜的潜在敏感性改进。我们旨在验证在其他站点使用亚毫米吹牛的使用，并使用PWV数据库来检测20年来当地气候变化的潜在签名。方法。我们修改了从亚毫米台台的不透明度转换为PWV的方法。现在，我们将接地温度作为转换方案的输入参数，因此可以达到更高的转化精度。结果。我们发现，相对于高原为28％的Cerro Chajnantor山顶的测得的PWV下降。此外，我们发现Chajnantor高原的两个位点之间的PWV差异为1：9％：Atacama Pathfinder实验（APEX）和宇宙背景成像仪（CBI）在Atacama大型毫米阵列（ALMA）中心附近。这种差异可能是由于局部地形条件有利于PWV中的差异。高原的尺度高度是从高原和Cerro Chajnantor峰会的测量值中提取的，值为1537 m。考虑到这项工作中从长期研究中获得的结果，我们看不到在分析的20年期间PWV趋势的证据，这些证据表明在这种时间范围内将表明气候变化。
Context. Interest in the use of the Chajnantor area for millimeter and submillimeter astronomy is increasing because of its excellent atmospheric conditions. Knowing the general site annual variability in precipitable water vapor (PWV) can contribute to the planning of new observatories in the area. Aims. We seek to create a 20-year atmospheric database (1997 - 2017) for the Chajnantor area in northern Chile using a single common physical unit, PWV.We plan to extract weather relations between the Chajnantor Plateau and the summit of Cerro Chajnantor to evaluate potential sensitivity improvements for telescopes fielded in the higher site. We aim to validate the use of submillimeter tippers to be used at other sites and use the PWV database to detect a potential signature for local climate change over 20 years. Methods. We revised our method to convert from submillimeter tipper opacity to PWV. We now include the ground temperature as an input parameter to the conversion scheme and, therefore, achieve a higher conversion accuracy. Results.We found a decrease in the measured PWV at the summit of Cerro Chajnantor with respect to the plateau of 28%. In addition, we found a PWV difference of 1:9% with only 27 m of altitude difference between two sites in the Chajnantor Plateau: the Atacama Pathfinder Experiment (APEX) and the Cosmic Background Imager (CBI) near the Atacama Large Millimeter Array (ALMA) center. This difference is possibly due to local topographic conditions that favor the discrepancy in PWV. The scale height for the plateau was extracted from the measurements of the plateau and the Cerro Chajnantor summit, giving a value of 1537 m. Considering the results obtained in this work from the long-term study, we do not see evidence of PWV trends in the 20-year period of the analysis that would suggest climate change in such a timescale.
