Interrelation between QBO and 11-year solar cycle effects in total column ozone over Europe     

Sergei A. Sitnov 《Climate Dynamics》2009,33(5):591-602

On the basis of total column ozone (TO) data obtained in the period of 1957–2007 at 10 ground-based European stations, characterized by long and highly reliable measurements, the effects of the quasi-biennial oscillation (QBO) and 11-year solar cycle (11-year SC), manifesting in TO are investigated. The results of comparative analysis of seasonal differences between different QBO/solar extremes convincingly demonstrate interrelation between the QBO and 11-year SC effects. It is shown that solar activity modulates the phase of the QBO effect so that the quasi-biennial TO signals during solar maximum and solar minimum are nearly in opposite phase. It is also demonstrated that isolated under permanent conditions of solar minimum or solar maximum the QBO effects in TO have the time scale of about 20 months. Solar modulation of the QBO effect makes the QBO a conductor of the solar cycle impact on TO over Europe. The mechanism of influence of the 11-year SC on the QBO and probably includes its impact on the QBO amplitude in the equatorial lower stratosphere, mainly through weakening of the equatorial easterlies during solar maximum.  相似文献   

Influence of the 11-year solar cycle on the effects of the equatorial quasi-biennial oscillation, manifesting in the extratropical northern atmosphere   总被引：1，自引：1，他引：0  

S. A. Sitnov 《Climate Dynamics》2009,32(1):1-17

Using the longest and most reliable ozonesonde data sets grouped for four regions (Japan, Europe, as well as temperate and polar latitudes of Canada) the comparative analysis of regional responses of ozone, temperature, horizontal wind, tropopause and surface pressure on the equatorial quasi-biennial oscillation (QBO effects), manifesting in opposite phases of the 11-year solar cycle (11-yr SC) was carried out. The impact of solar cycle is found to be the strongest at the Canadian Arctic, near one of two climatological centres of polar vortex, where in solar maximum conditions the QBO signals in ozone and temperature have much larger amplitudes, embrace greater range of heights, and are maximized much higher than those in solar minimum conditions. The strengthening of the temperature QBO effect during solar maxima can explain why correlation between the 11-yr SC and polar winter stratospheric temperature is reversed in the opposite QBO phases. At the border of polar vortex the 11-yr SC also modulates the QBO effect in zonal wind, strengthening the quasi-biennial modulation of polar vortex during solar maxima that is associated with strong negative correlation between stratospheric QBO signals in zonal wind and temperature. Above Japan the QBO effects of ozone, temperature, and zonal wind, manifesting in solar maxima reveal the downward phase dynamics, reminding similar feature of the zonal wind in the equatorial stratosphere. Above Europe, the QBO effects in solar maxima reveal more similarity with those above Japan, while in solar minima with the effects obtained at the Canadian middle-latitude stations. It is revealed that the 11-yr SC influences regional QBO effects in tropopause height, tropopause temperature and surface pressure. The influence most distinctly manifest itself in tropopause characteristics above Japan. The results of the accompanying analysis of the QBO reference time series testify that in the period of 1965–2006 above 50-hPa level the duration of the QBO cycle in solar maxima is 1–3 months longer than in solar minima. The differences are more distinct at higher levels, but they are diminished with lengthening of the period.  相似文献   

2000年中国地区地磁场长期变化的区域特征   总被引：10，自引：2，他引：8       下载免费PDF全文

徐文耀  魏自刚  夏国辉 《地球物理学报》2005,48(3):551-560

本文用中国地磁场复测点和地磁台站资料,建立了2000年代中国参考地磁场长期变化模型CGRF-SV2000.模型显示,中国地区地磁场变化比较平缓,X、Y、Z、H、D、I、F七个地磁要素的“无符号平均年变率”分别为122 nT/a、82 nT/a、438 nT/a、118 nT/a、096(′)/a、299(′)/a、224 nT/a,比国际参考地磁场IGRF给出的全球年变率约小1/3到1/2.各地磁要素的变化显示,地磁北极正在向中国移近,或者说,中国正在向高地磁纬度方向移动,平均移动速度约为3(′)/a.磁偏角变化还显示,中国地区东西部偏角差异继续扩大.作为检验和对比研究,本文利用第8代国际参考地磁场（IGRF）模型,分析了全球地磁场长期变化的时空特征,讨论了全球长期变模型IGRF_SV与中国长期变模型CGRF_SV的异同点.对比分析表明,中国地区地磁场的长期变化与全球长期变化总趋势基本符合,但是,CGRF_SV也表现出一些特有的局部异常特征.  相似文献   

地球重磁位场辅助水下潜艇导航仿真研究   总被引：1，自引：0，他引：1  

郑晖  王勇  王虎彪  武凛 《武汉大学学报(信息科学版)》2012,37(10)

根据卫星测高反演的重力异常和全球地磁异常格网,构造了西太平洋海域2′×2′重力异常和磁场异常数据作为基准信息,结合SITAN滤波算法在该海域上的两块特征区域上,对比了重力和地磁辅助导航的效果。仿真结果表明,重力和地磁辅助导航的结果与潜艇航线上的重力和磁力信息丰富程度密切相关,两块区域上的两种辅助导航算法的精度都在2nmile左右。  相似文献   

Defiled Cities     

Derek Gregory 《Singapore journal of tropical geography》2003,24(3):307-326

Edward Said laid some of the foundation stones for postcolonialism, but this project has — for the most part — ignored the pressing question of Palestine that has been the goad for so much of Said's own work. This essay discusses some of the ways in which, in the wake of September 11, the Israeli government of Ariel Sharon took advantage of the so-called "war on terrorism" to ratchet up the dispossession of the Palestinian people. It also seeks to show that imaginative geographies are never merely representations — they are also performances of space — and that, in this case (as in others), they have served to rationalise and radicalise colonial aggression, ultimately through the prosecution of a necropolitics.  相似文献   

南大西洋地磁异常区的辐射环境与低轨卫星粒子辐射通量计算   总被引：5，自引：0，他引：5  

焦维新  濮祖荫  方晓华  傅绥燕 《地球物理学报》1999,42(2):163-168

利用国际地磁参考场模型ＩＧＲＦ９０,分析了南大西洋异常（ＳＡＡ）区磁场变化的特征,计算了低轨卫星轨道积分粒子辐射通量及其随年代的变化。结果表明,在ＳＡＡ上空,同一高度上的磁场随时间的推移而减弱,粒子辐射通量随时间的推移而增加．对不同高度的卫星,轨道积分粒子辐射通量随年代的变化相差很大,低轨（＜１０００ｋｍ）卫星的变化明显,而＞１０００ｋｍ时变化很小．粒子辐射通量随时间变化的主要原因是ＳＡＡ区的磁壳结构畸变和“移动”,因此,计算不同年代的轨道粒子辐射通量,应使用同年代的磁场模型。近期卫星测量结果表明,这一论断与观测相符。本文提供的计算轨道积分粒子通量方法,结果的可靠性较高,对卫星的合理设计,载人飞船的辐射防护以及卫星的正常运行都有重要参考价值。  相似文献   

Tracing the source of 3,3'-dichlorobiphenyl found in samples collected in and around Halifax Harbour   总被引：1，自引：0，他引：1  

King TL  Yeats P  Hellou J  Niven S 《Marine pollution bulletin》2002,44(7):590-596

3,3'-dichlorobiphenyl (IUPAC No. 11), a chlorobiphenyl (CB) that is not generally analysed in environmental studies of CBs, is found, sometimes at high concentrations, in water, suspended particulate material, biota and sediments from Halifax Harbour, NS, Canada. The results presented demonstrate the need for investigations of non-Aroclor CBs like CB 11. Not only can they have rather elevated environmental concentrations like those reported here for CB 11, but they also can be members of the more toxic non-ortho class of CBs and thus important from a toxicity standpoint. The focus of this paper was to investigate the possible sources of CB 11, a trace constituent of commercial mixtures, but dominant in various environmental compartments of Halifax Harbour.  相似文献   

新集二矿东翼11-2煤层提高开采上限的研究与实践     

苏毅  徐德成 《中国煤田地质》2004,16(6):29-31

为了提供提高煤层开采上限的根据，开展了新集井田东翼11-2煤层防水煤柱厚度、岩性组合特征及含水性的研究，井进行了推复体夹片地层下井田东翼11-2煤层的开采实验，在26m防水煤柱下实现1111200工作面安全回采，取得较好的经济效益。  相似文献   

The 10th-Generation International Geomagnetic Reference Field   总被引：8，自引：0，他引：8  

International Association of Geomagnetism  Aeronomy  Division V  Working Group VMOD: Geomagnetic Field Modeling 《Geophysical Journal International》2005,161(3):561-565

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离子色谱法快速测定土壤中碘量   总被引：10，自引：4，他引：10  

佘小林 《岩矿测试》2005,24(2):145-147

优化了碘的离子色谱分离和测定条件，仅使用保护柱IonPacAG11柱，即可快速测定土壤中的碘。方法检测限0．04μg／g(3倍的标准偏差)，测定了8个国家一级标准物质中的痕量碘，验证方法可行性，并且结果与标准值相符，相对标准偏差(RSD)小于10％(n=12)。该方法适用于大批量化探样品中碘量的分析。  相似文献