Spectral analysis of planetary waves seen in ionospheric total electron content (TEC): First results using GPS differential TEC and stratospheric reanalyses

The coupling of the neutral atmosphere and the ionosphere through planetary waves (PW) (zonal wavenumber 0–5) is investigated by spherical harmonic analyses of the ionospheric total electron content (TEC). These analyses detect mean variations, standing and travelling waves which are assumed to be signatures of PW. Database used for TEC analyses are 3 years of hourly TEC maps covering the higher middle and polar latitudes. They are regularly produced by DLR Neustrelitz. The obtained results are compared with PW analyses using NCEP/NCAR and Met Office stratospheric reanalyses. Case studies show that signatures of PW occur simultaneously in the middle atmosphere and ionosphere.     

青藏铁路沿线的天灾及其预测方法探索

本文统计了青藏铁路沿线50多年来的强地震、雪灾和夏季旱涝,并根据地气耦合原理对其成因进行了分析,找到了一些很好的预报因子,初步得出了以下结论：未来10年35оN以南的沿线地区将很少会发生Ms＞6级的强震;“本区强震年”和8月沿线为地热涡控制时铁路沿线会发生雪灾;本区冬季为地冷涡控制时一般为夏旱年.     

耦合模式对印度洋偶极子的模拟研究

利用一个海洋-大气-陆面系统耦合模式,模拟分析了热带印度洋的季节和年际气候变化特征。该模式很好地模拟出热带印度洋区域的季节变化特征,对热带印度洋强的局地年际耦合信号-偶极子模拟也比较成功,模拟结果与已有的观测分析以及高分辨率耦合模式模拟结果接近。     

Saltzman气候模式的新格式及其应用

云反馈是影响气候变化的重要因子,它导致气候模拟的不确定性。为此,针对云反馈提出了一种参数化方案,随后推导一个包含云反馈在内的大气海洋海冰模式。云反馈是通过短波辐射引入的,而二氧化碳温室效应是在长波辐射中引入的。经过繁杂的推导,得到了模式方程组,它是一个双变量非线性常微分方程组。通过数值计算模拟了 Ｃ Ｏ２ 变化时气候系统的增温量。平衡试验表明,当 Ｃ Ｏ２ 从３３０×１０－ ６增加到６６０×１０－ ６时,全球平均增温量为１７℃,瞬变试验时,增温量为１３℃。     

副高的地气耦合效应

中国是季风气候,每年西太平洋副高要北移和南退。在它的边缘上降大雨,有时会致洪。本指出这种副高压在地面上时,在其边缘上地层会产生引张环。此环内地下水铁于逸出,可迭加在绕副高边缘运移的水汽中,如有北方冷空气南下相遇,则增加降雨强度。另外,引张环中还有温室气体逸出,可使低层大气增温,这有助于副高边缘区降大雨致洪。这就是副高的地－气耦合效应。如果引张环和外侧有地震活动,则地下活动相对剧烈,副高的地－气耦合效应加强,同时也有利于副高向地震活动区移动。     

一、二维耦合模式在“胶莱运河”中的应用

运用一、二维耦合模型,考虑季节性风生海流和潮流的作用,对开凿胶莱运河改善渤海水质的效果进行了初步研究.以海水半交换周期和运河的净流量为衡量的主要指标,进行四种运河规模的模拟实验,评估各种开渠规模治污的效益.模拟结果显示,开凿运河后,运河的流向随潮汐过程变化,但能够形成少量由胶州湾向莱州湾的净流量,通过运河的年净流量与运河规模成正比,为渤海海峡年过水量的1‰-2.5‰.运河规模达到5000m(宽)×20m(深),海水半交换周期仅缩短3%.因此,开凿胶莱运河改善渤海水质的效果不明显,渤海污染治理的关键应该是污染源头控制和管理.     

川西前陆盆地侏罗纪构造层序地层格架内沉积充填特征

为了研究侏罗纪龙门山造山带与川西前陆盆地盆山关系,以侏罗系3个构造层序(TS1~TS3)体系域(BE, BW)为研究的基本单元,通过对川西前陆盆地构造层序充填特征的研究发现:龙门山造山带构造运动与沉积盆地的构造层序充填特征吻合较好,并且龙门山造山带北段,中段,南段在各期次构造活动中活动情况具有差异。TS1BE期,川西前陆盆地北部和南部地区都发育有冲积扇-扇三角洲沉积,中部地区为三角洲沉积,显示该期龙门山造山带北段和南段构造活动可能较为剧烈,中段相对较平缓。TS1BW期,川西前陆盆地北部和南部地区都以湖泊沉积为特征,仅在川西前陆盆地中部地区发育有三角洲沉积,显示本期龙门山造山带构造活动不发育,较为平稳。TS2BE期,川西前陆盆地北部和南部地区自西而东为冲积扇,三角洲—滨湖、浅湖沉积环境,中部地区为三角洲沉积,显示龙门山造山带又一次剧烈隆升,且北段和南段活动较为剧烈,中段相对较弱。TS2BW期,层序充填结构表明龙门山造山带北段和中段活动情况再次趋缓,但南段构造活动仍然较为活跃。TS3BE期,川西前陆盆地北部和南部地区发育有冲积扇沉积,中部则以三角洲-湖泊沉积为特征,显示该期龙门山造山带北段和南段都发生了较为剧烈的构造隆升运动,龙门山造山带中段,构造活动相对较为平缓。TS3BW期,龙门山造山带北段和中段构造活动减弱,南段活动持续加剧,于芦山两河口地区沉积有巨厚的冲积扇沉积物。     

高层建筑物荷载与地下水开采叠加作用下的地面沉降特征

在地下水开采和高层建筑荷载叠加作用下,城市地面沉降分布愈加复杂.以天津塘沽地区为例,考虑到土体在固结沉降中的平衡条件、弹性本构条件、变形协调条件和水流连续条件,以比奥固结理论为基础,建立了高层建筑荷载和地下水开采叠加作用下三维地面沉降模型,采用有限元方法进行了数值计算.结果表明,高层建筑物的附加荷载作用在其建成后的3～...     

Coupling action of rainfall and vehicle loads impact on the stability of loess slopes based on the iso-water content layer

To clarify the changes in slope stability of loess slopes under the coupling action of rainfall and vehicle loads. Experiments with different water contents under different environmental conditions were carried out indoors, and the relationship function between water content and shear strength parameters was obtained; Secondly, based on Geostudio, an equivalent layered calculation model of water content-strength parameters of loess slope was established, the variation law of soil sample matrix suction with volumetric water content was measured by volumetric pressure plate tester. Finally, by using a combination of finite element analysis of saturated/unsaturated seepage and limit equilibrium analysis of slope stability, the SLOPE/W module in the modeling software GeoStudio is used to calculate and analyze the effects of vehicle loads, rainfall intensity, rainfall duration, and other working conditions on the stability of loess slopes, respectively. The results show that when the lane is in the middle of the slope, the vehicle load parameters have little effect on the uphill stability, but have a greater impact on the downhill; With the increase in rainfall, the change curves of the slope safety coefficient gradually overlap when the vehicle loads are four-axis,five-axis, and six-axis. This shows that when studying the change of slope safety factor under the dual influence of vehicle loads and rainfall, rainfall is the main cause of slope stability; The change rate of slope safety factor increases gradually with the increase of rainfall, and the change trends of the upper, lower and overall parts of the slope are similar.