Direct Observations of Atmospheric Transport and Stratosphere-Troposphere Exchange from High-Precision Carbon Dioxide and Carbon Monoxide Profile Measurements

The balloon-borne Aircore campaign was conducted in Inner Mongolia,China,on June 13 and 14 2018,which detected carbon dioxide(CO_2) and carbon monoxide(CO) profiles from surface to 24 km,showing strong positive and negative correlations between 8 km and 10 km on 13 and 14 June,respectively.Backward trajectories,meteorological analyses,and CO_2 horizontal distributions were combined to interpret this phenomenon.The results indicated that the source region experienced a stratospheric intrusion and exhibited a large horizontal CO_2 gradient;namely,lower CO concentrations corresponded to higher CO_2 concentrations and vice versa.The laminar structure with multiple origins resulted in the highly negative correlation between CO_2 and CO in the upper troposphere on 14 June.The contribution of stratospheric air mass to the upper troposphere and that of tropospheric air mass to the lower stratosphere were 26.7% and24.3%,respectively,based on a mass balance approach.Another interesting phenomenon is that CO_2 and CO concentrations increased substantially at approximately 8 km on 13 June.An analysis based on the backward trajectory implied that the air mass possibly came from anthropogenic sources.The slope of CO_2/CO representing the anthropogenic sources was 87.3 ppm ppm~(-1).In addition,the CO_2 profile showed that there was a large CO_2 gradient of 4 ppm km-1 within the boundary layer on 13 June,and this gradient disappeared on 14 June.     

The possible influences of the increasing anthropogenic emissions in India on tropospheric ozone and OH

A 3-D chemical transport model (OSLO CTM2) is used to investigate the influences of the increasing anthropogenic emission in India. The model is capable of reproducing the observational results of the INDOEX experiment and the measurements in summer over India well. The model results show that when NOx and CO emissions in India are doubled, ozone concentration increases, and global average OH decreases a little. Under the effects of the Indian summer monsoon, NOx and CO in India are efficiently transported into the middle and upper troposphere by the upward current and the convective activities so that the NOx, CO, and ozone in the middle and upper troposphere significantly increase with the increasing NOx and CO emissions. These increases extensively influence a part of Asia, Africa, and Europe, and persist from June to September.     

一次典型梅雨锋锋面结构分析

1999年梅雨期在长江中下游维持着一条典型的梅雨锋 ,锋面和梅雨雨带呈东西走向 ,从中国的四川省一直延伸到日本。锋面两侧的温度及湿度对比明显 ,并且其上有数个中间尺度的低涡沿梅雨锋依次向东移动发展 ,在长江中下游造成严重的梅雨暴雨和洪涝。文中分析了 1999年这次典型梅雨锋的锋面结构。结果表明 ,从温度场看 ,由于梅雨区对流和降水的显著发展 ,梅雨锋的低层温度对比几近消失 ,其中上部仍具有典型的上宽下窄的锋面结构 ,锋面随高度向北倾斜。在低层经向温度场呈现复杂的暖 -冷 -暖的结构 ,即北部华北平原为地面感热加热造成的相对较暖的变性极地大陆气团 ,中间为冷空气南下和降水冷却造成的相对较冷的梅雨区 ,南部是相对较暖的热带海洋气团。在这种温度场下 ,由北部低层变性暖气团与梅雨区偏冷空气形成了明显的温度对比区 ,文中定义这个区域为梅雨赤道锋。因而 ,在低层东亚梅雨区的锋区结构由梅雨赤道锋和减弱的梅雨锋构成。在 6 0 0hPa以上前者消失 ,只有单一的极锋型的梅雨锋结构。在此分析的基础上文中给出了东亚梅雨期锋面结构模型图。另外还指出 ,从假相当位温场分析 ,主要表现出梅雨区的深厚对流。降雨引起了高θse带及其南北高θse梯度区 ,其北侧高θse梯度区大致相当于梅雨锋 ,而南侧高θs     

Late Mesozoic crust-mantle interaction and lower crust components in South China: A geochemical study of mafic granulite xenoliths from Cenozoic basalts

Mafic granulite xenoliths have been discovered in many volcanoes (especially alkali basalt and kimberlite) all over the world. They formed generally in lower crust, and recorded lots of in- formation on the lithosphere formation and crust-mantle interacti…     

中南半岛影响南海夏季风建立和维持的数值研究

利用美国大气研究中心研制的第三代公共气候模式(CCM3)模拟了中南半岛对南海夏季风的建立和维持的影响,数值试验结果表明,中南半岛对南海夏季风的建立和维持起了非常重要的作用.同时还就中南半岛影响南海夏季风建立和维持的机制进行了讨论.     

焦作市4—9月短期降水精细化预报系统

在降水时空变化研究的基础上，完成辖区降水区划；用计算机识别T213风场中槽线、切变线等影响系统，并按其相对于预报站方位，确定对其影响强度指数，组合预报因子，建立判别方程，制作分县0～12小时、12～24小时降水分级预报。经检验，系统对降水落区有较强预报能力。     

夏季青藏高原东部降水变化与副热带高压带活动的研究

用青藏高原上常规的台站资料和NCEP/NCAR的再分析资料,分析和研究了1993/1994年夏季5—8月青藏高原东部降水变化与西太平洋副热带高压南北移动的关系。结果表明:1993年夏季的副热带高压异常偏南,5—8月副高脊线北移过程中,还伴有准双周南北移动过程;而1994年夏季的副热带高压异常偏北,5—8月副高脊线北移过程中,则主要伴有30—60d的低频变化的南北移动过程。同时,在分析青藏高原上的天气变化特征时,发现这两年高原东部的降水变化特征也有明显的不同,夏季高原上降水的活跃和中断与副高脊线南北移动变化有类似的特征。因此,夏季西太平洋副热带高压南北移动可能与高原东部降水的中断/活跃有一定的关系。     

基于动力统计模型重构的副热带高压中长期预报

基于T106数值预报产品500 hPa位势高度场序列,用EOF方法对位势场序列进行时、空分解,在考虑相邻时段位势场空间模态基本稳定的前提下,引入动力系统重构的思想,以EOF分解的空间模态时间系数序列作为动力统计模型变量,用遗传算法全局搜索和并行计算优势,进行了模型参数的优化反演,建立了EOF分解的时间系数的非线性预报模型。通过模型积分和EOF的时、空重构,实现了副热带高压活动场的中长期预报。试验结果表明,在短期预报(1—5 d)该模型与T106模式的预报效果大致相当;但对于中长期预报(≥5 d),其预报效果优于T106预报产品;特别是10 d以上的预报结果对副热带高压的形态和范围仍然能较为准确地描述。该研究方法对副热带高压等复杂天气系统和要素场预报提供了一种新的思路。     

Element diffusion ability in metasomatic agents and its effect on chemical characteristics of metasomatized peridotites

The partial melting and metasomatism are two most important geological processes of changing chemical compositions of mantle. Extracting partial melt from primitive mantle leads residual mantle to deplete in- compatible elements, whereas the metasomatism …