基于全球超导重力仪观测研究海潮和固体潮模型的适定性

利用国际地球动力学合作观测网络中20个台站22个高精度重力潮汐观测系列综合研究了目前使用的海潮和固体潮模型的适定性. 对原始观测数据实施仔细的预处理, 利用国际标准算法计算了潮汐重力参数. 基于负荷理论和不同全球海潮模型获得了8个主波的重力负荷矢量, 用二维平面插值技术获得了14个小波的负荷改正值. 顾及不同潮波振幅特征, 提出了计算台站平均观测残差和剩余残差矢量的“非等权均值法”, 分析了海潮负荷改正的有效性和振幅因子与理论模型间的差异, 同时还讨论了仪器标定问题. 获得了经海潮负荷改正后全球各台站平均潮汐重力参数, 结果说明观测与理论模型间的差异小于0.3%, 最大仪器标定误差不超过0.5%. 另外文章还用地表重力实测数据证实了Mathews理论中相对于周日O₁波而言, K₁波相位滞后略呈正值的结论.     

PRIMARY STUDY OF SULFATE AND CARBONACEOUS AEROSOLS IN BEIJING

Results of our aerosol study, performed during 1983-1984 in Beijing, demonstrate that ambient carbonaceous aerosols are derived mainly from coal combustion. Different SO, oxidation processes have been observed in summer and winter. The winter sulfate appears to be produced locally and associated with products of incomplete combustion.     

利用FM-CW雷达研究对流层降水过程

由于FM-CW雷达硬件、信号处理以及多普勒偏振FM-CW雷达DARR可用性方面的进步,FM-CW对流层雷达领域可能出现新的突破。DARR具有很高的距离、多普勒速度和偏振分辨率。该雷达能获得每秒几厘米的多普勒分辨率,及每秒±9米的最大多普勒范围。使用两个直接安装在发射和接收天线中心馈电器后面的机械偏振器,工作时偏振角的范围在±90度之间。本文给出了实测的多普勒速度和测偏振反射率廓线。根据这些廓线对层状云降雨融化过程和雨滴谱进行了模拟和验证。     

大气中的臭氧和影响它的各种微量物质

一、引言近年来自然因素和人为因素引起气候变化和气候变迁问题,日益引起国际社会的注意。在多种气候变量中,臭氧是人们十分注意的一种,他的自然变化很大,同时人类活动又可能改变它。因为臭氧在大气辐射过程中起着重要作用,因而不只影响生物过程,而且也是控制地球气候系统的重要因素。大气中的臭氧受着它与各种微量成分的化学反应的强烈影响,事实上,它的破坏率就大受这些微量成分的浓度的制约。这方面最重要的化学反应涉及到氢、氨和具有催化性质的氯的化合物。众所周知,臭氧强烈地吸收太阳紫外辐射,主要吸收带(哈特雷带)在200到300nm(1nm=10~(-9)米)。另外,臭氧在红外波段有许多旋转振动吸收带,其中最强的在9570nm附近。由于吸收紫外辐     

Mesoscale Vortex Generation and Merging Process： A Case Study Associated with a Post-Landfall Tropical Depression

An observational analysis of satellite blackbody temperature (TBB) data and radar images suggests that the mesoscale vortex generation and merging process appeared to be essential for a tropical-depression-related heavy rain event in Shanghai, China. A numerical simulation reproduced the observed mesoscale vortex generation and merging process and the corresponding rain pattern, and then the model outputs were used to study the related dynamics through diagnosing the potential vorticity (PV) equation. The t...     

用微型干涉仪测地终端设备(MITES)测量基线的精度估计

<正> 1980年12月17日将轻便的MITES天线(见Bull.Geod.53,139—163,1979)设在Haystack天文台附近三座测量标志的顶部。这些天线获得了全球定位系统卫星(NAVSTAR/GPS)的射电干涉测量结果,经过分析后,便确定了这些测量标志之间的基线向量。     

Preface to Special Issue on the National Report to the IUGG Centennial by CNC-IAMAS(2011–2018)

正The 27th General Assembly of the International Union of Geodesy and Geophysics(IUGG), which also marks the 100 th anniversary of IUGG, will be held during 8–18 July 2019 in Montréal, Canada. The Chinese National Committee(CNC)for the International Association of Meteorology and Atmospheric Sciences(IAMAS) has a more than 30-year tradition of     

Retrieval of water vapor profiles with radio occultation measurements using an artificial neural network

A new method applying an artificial neural network （ANN） to retrieve water vapor profiles in the troposphere is presented. In this paper, a fully-connected, three-layer network based on the backpropagation algorithm is constructed. Month, latitude, altitude and bending angle are chosen as the input vectors and water vapor pressure as the output vector. There are 130 groups of occultation measurements from June to November 2002 in the dataset. Seventy pairs of bending angles and water vapor pressure profiles are used to train the ANN, and the sixty remaining pairs of profiles are applied to the validation of the retrieval. By comparing the retrieved profiles with the corresponding ones from the Information System and Data Center of the Challenging Mini-Satellite Payload for Geoscientific Research and Application （CHAMP-ISDC）, it can be concluded that the ANN is relatively convenient and accurate. Its results can be provided as the first guess for the iterative methods or the non-linear optimal estimation inverse method.     

一堆气候模式的灵敏度分析

在本文中我们设计了一个只有垂直方向的一维气候模式。该模式可以用来研究大气中CO_2气体浓度从330增加到660ppm时地面温度的变化。同时我们将分析几个反馈机制对气候系统灵敏度的贡献,其中包括大气湿度反馈、云反馈和地面反射率反馈等机制。     

Large Scale Perturbations in Extratropical Atmosphere-Part Ⅱ: On Geostrophic Waves

We have examined, in Part Ⅰ, the propagation mechanism and geostrophic property of classical Rossby waves in a non-divergent barotropic atmosphere. As we found that the non-divergent Rossby waves do not propagate in a hydrostatically equilibrium atmosphere, and do not manifest a good geostrophic property, an alternative large scale circulation pattern of geostrophic waves has been proposed (McHall, 1991a). The propagation mechanism and geostrophic property of these waves are examined in the present study.