大气透明度数值计算模式研究

In view of the fact that the important meaning and physical demand of Chinese site survey,modeling of calculating transparency over China is proposed,and the research mainly includes aerosol and precipitable water vapor.Meteorological parameters of astronomical observatories are obtained by using the atmospheric numerical models,then pricipitable water vapor is calculated with the mothod of water vapor mixture ratio parametrization model,and through the atmospheric numerical model computation output aerosol parameters,and this method has been confirmed feasible for site assessment.By using atmospheric numerical model,the distribution and variation of meteorological parameters 、aerosol(optical thickness) and precipitable water vapor of observatoies are obtained,and its mature reliable application can bring the enormous convenience for site survey:1)the method can be used for transparency of atmospheric in site survey all over China,2)for long-term variation of transparency of atmospheric,3)for the analysis of atmospheric characteristic comparison in regional site survey,4)for site survey on high fraction image and other technologies,5)for the forecast of site survey for ultra-large telescope.The project will fill an extremely important research blank for the remote study of site survey,and the research technology will be highly enhanced,and the demand for solar site survey and spatial project will be satisfied,quickening the pace of site survey.

鉴于中国天文选址的重要意义和实际需求，提出开展中国地域的大气透明度数值计算方法研究，研究参量气溶胶和大气水汽含量。利用大气模型数值计算得到天文台址的气象参数，然后以水汽混合比参量化模型计算大气水汽含量，且通过大气数值模型计算输出气溶胶参数，已证实是一种可行的台址评价方法。通过大气模型数值计算，能够获得台址区域的气象要素、气溶胶（光学厚度）、大气水汽含量的分布和变动情况，其成熟可靠的应用将为天文选址工作带来极大便利：1）用于进行全国大范围的大气透明度选址调查，2）用于研究大气透明度的长期变化，3）用于各地天文台站大气特性的横向比较，4）用于高分率成像等技术的天文观测，5）用于超大型望远镜台站的观测预报。项目实施将为天文选址远程研究填补一项极重要的研究空白，极大提高天文选址远程研究技术，满足后期太阳选址和空间项目的选址需求，加快选址进程。

基于中国西部天文战略选址的重要意义和实际需求，开展大气透明度数值计算方法研究。利用美国NCEP/NCAR的WRF-CHRM耦合模式及FNL再分析资料计算得到区域及具体站点的各项气象参数，通过水汽混合比参量化模型计算大气水汽含量，通过消光系数计算气溶胶参数，计算获得全国及青藏高原地区各项气象要素、大气水汽含量及气溶胶参量的分布和变化特征。