Comparison of the Double Summer Monsoon Troughs over East Asia

Based on NCEP/NCAR reanalysis data, an investigation has been carried on the comparison of the double summer monsoon troughs over East Asia, which refer to the subtropical summer monsoon trough (subtropical-trough) and the South China Sea summer monsoon trough (SCS trough), respectively. The results show that the SCS trough is stronger than the subtropical-trough either in convergence or convection. The subtropical-trough extends up to higher levels and inclines northward with altitude, while, the SCS trough extends up to a lower level, and its position is seldom changed. The SCS trough establishes early and abruptly with the low level positive relative vorticity appearing suddenly, and retreats slowly, but the subtropical-trough establishes step by step with the positive relative vorticity initially over the Yunnan-Guizhou Plateau and Guangxi areas spreading gradually northeastward, and withdraws rapidly. The onset of SCS trough is obviously indicated by the reverse of the easterly, but the establishment of the subtropical-trough is characteristic of the westerly enhancement. The subtropical-trough has clearly frontal property, yet the SCS trough has not.     

腾格里沙漠东南缘晚第三纪古风成砂及其环境

通过对地层、沉积构造、粒度、石英砂表面微结构及动物群、孢粉组合的分析表明,晚第三纪期间腾格里沙漠东南缘及附近地区曾呈现类似现代风沙迁移、堆积的风沙地貌过程。当时气候炎热干旱,干湿季变化明显,生物气候带为亚热带疏林草原甚至荒漠草原。     

湛江港浮游硅藻类初步调查报告

湛江港位于N21°10’，E110°24’，地处热带与亚热带交界处。气候温和，年平均气温为33.5℃左右。湛江港港湾宽阔，从港口至港尾长达六十多公里，整个湛江港海域分为外海和内湾两个区：硇洲岛和东海岛的东南沿海属外海区，这个海区的海水受南海潮流、鉴江河、     

Modeling and Diagnostic Studies on the Variations of the Subtropical High over the Western Pacific from 1880 to 1999

Index series of Subtropical High over the western Pacific was extended to AD 1880 by using of statistical and modeling method.Reconstructed indices by both methods show good accordance each other.Association of the indices to the rainfall patterns over eastern China indicated the robustness of the reconstructions.     

我国亚热带西部山区积温有效性研究

本文通过亚热带西部山区与亚热带东部地区积温有效性的对比指出,西部亚热带山区无效积温少,有效积温高于或相当于东部地区;西部的日温周期更适宜于亚热带植物的生长,西部山区能量等效积温比实际积溫高500—1000℃。最后提出划分亚热带西北界限的指标为≥10℃积温>4000℃(湿润区)和>4200℃(半干旱区)。     

气候变化背景下秦岭-淮河地区亚热带北界变化

基于1970—2019年秦岭-淮河地区气象站点观测数据,以日均温稳定≥10℃持续日为主要指标,以1月平均气温为辅助指标,借助薄盘样条插值（TPS）及基于数字高程模型（DEM）的普通克里金插值法,探讨秦岭-淮河地区亚热带北界对全球气候变暖及变暖“停滞”现象的响应及变化。结果表明,1970—2019年秦岭-淮河地区日均温稳定≥10℃持续日及1月平均气温均呈不同程度的上升趋势,但二者高低值的分布年份并不相同;50年来亚热带北界在秦岭段出现了明显的向高海拔地区移动的趋势,其中,秦岭南坡共计抬升153.3 m,北坡抬升148.8 m。在变暖“停滞”期间,秦岭南、北坡亚热带北界所处海拔的变化具有较高的同步性,但在1980s至1990s期间差异性较大。1970—2019年亚热带北界在淮河段北移1.3个纬度以上,在115°E附近甚至达到3个纬度,与中国过去2000年亚热带北界曾到达的最北位置相仿;从年代际上来看,亚热带北界在1990s期间北移最明显,黄河流域下游部分区域已由暖温带逐渐转化为亚热带。