Influence Of The Atmosphere On Earth Rotation: What New Can Be Learned From The Recent Atmospheric Angular Momentum Estimates?     

Aleksander Brzeziński  Christian Bizouard  Sergei D. Petrov 《Surveys in Geophysics》2002,23(1):33-69

The interaction between the atmosphere and the underlying solid mantle is oneof the most important sources of changes in all three components of theEarth's rotation vector on different time scales. In this paper the NCEP/NCARreanalysis time series of four times daily atmospheric effective angularmomentum (EAM) estimates is used to investigate some selected aspects of theatmospheric influence on Earth rotation. Emphasis is placed on thecontroversial features which were difficult or impossible to study using theoperational EAM data, such as excitation of the free oscillations in polarmotion, the Chandler wobble (CW) and the free core nutation (FCN), or theroles of diurnal and semidiurnal atmospheric tides and atmospheric normalmodes in the rotational dynamics of the Earth.  相似文献   

OBSERVATIONAL STUDY OF MERIDIONAL VARIATION OF UV-B RADIATION DURING VOYAGES TO THE ARCTIC AND ANTARCTIC REGIONS^*          下载免费PDF全文

LU Longhu  BIAN Lingen  LU Changgui  CHENG Yanjie 《Acta Meteorologica Sinica》2002,16(2):253-260

Based on 1999-2000 observations made by the first Arctic and sixteenth Antactic scientific voyages,a study is undertaken about the meridional surface UV-B (B band ultraviolet rays) variations in 75°N-70°S.It is mitigated as a function of latitudes and marked by lower radiation averaged over the Northern Hemisphere (NH) than over the Southern Hemisphere (SH),with its daily course basically similar to that of total radiation.Around polar summer noon hours (localtime) and where ice albedo is maximum,the strongest UV-B irradiance on the surface perpendicular to sun's beams as found at equatorial latitudes is measured sometimes.In the areas near Zhongshan Station the increase of surface UV-B radiation shows a close relation to the decrease of ozone in the higher atmosphere but it has a less intimate relation with its concentration at ground.  相似文献   

Earth Rotation Parameters 1899.7–:1992.0 After Reanalysis Within The Hipparcos Frame     

Jan. Vondrák 《Surveys in Geophysics》1999,20(2):169-195

Earth rotation parameters (ERP) in the interval 1899.7–1992.0 are obtained from re-analysis of the observed latitude/universal time variations by optical astrometry. Hipparcos Catalogue is used to define the celestial reference frame, within which the ERP are described, with special care devoted to 'problematic' double and/or multiple stars. The terrestrial reference frame is defined by the adopted latitudes/longitudes of participating instruments and their secular motions as given by the NUVEL-1 NNR model of plate motions, and it is chosen to be very close to the International Terrestrial Reference Frame (ITRF). More than four million observations made with 48 different instruments at 31 observatories, located all over the world, are utilized to determine polar motion, celestial pole offsets and (after 1956) universal time UT1, all at 5-day intervals. Along with these parameters, the combinations of Love and Shida numbers, governing the tidal variations of the local verticals at individual observatories, are also determined. The analysis of the results covering almost a century, namely the long-periodic polar motion and length-of-day changes, is presented.  相似文献   

Gravity anomalies derived from Seasat, Geosat, ERS-1 and TOPEX/POSEIDON altimetry and ship gravity: a case study over the Reykjanes Ridge   总被引：1，自引：0，他引：1  

Cheinway Hwang  Barry Parsons 《Geophysical Journal International》1995,122(2):551-568

  相似文献   

北极海冰对青海省春季（3—5月）降水的可能影响   总被引：2，自引：2，他引：2  

唐红玉  时兴合等 《气象科学》2001,21(2):216-221

用北极海冰面积指数及北半球500hPa高度资料、青海省春季降水资料，分析了它们之间的相互关系。结果表明北极海冰面积Q指数和M指数与我省春季降水的相关性较为一致，即相关性较好的区域皆为Ⅱ区，相关性较好的月份毕为当年1、3、4月及春季3－5月和前一年的6－8月；海冰是通过影响大气环流系统从而影响我省春季降水的，当年春季和前一年夏季海冰面积的变化对青海省春季降水的影响最明显。  相似文献   

海上船噪声干扰的压制技术   总被引：2，自引：0，他引：2  

张雅勤  张美华  宁俊瑞 《物探与化探》2001,25(4):290-293

船噪声干扰是海上地震数据中的主要干扰源之一,由于大多数情况下具有侧面波的性质,常规去线性规则干扰的处理技术无法将其压制。采用空间域转换的方法,将共炮点域中的规则船干扰,转换为共偏移距域内的随机干扰,用现今流行的随机干扰压制技术,就可以达到压制船干扰的目的。文中给出了压制船干扰的实例。  相似文献   

南极极夜期间臭氧含量变化及其与平流层风温关系          下载免费PDF全文

熊康  胡荣明  石广玉 《极地研究》1992,4(2):45-55

本文利用昭和基地 (6 9°0 0′ S,3 9°3 5′ E) 1 982～ 1 987年的臭氧总量的探空资料 ,着重分析了1 987年南极昭和站极夜期间臭氧含量变化与 5 0 h Pa风速、气温及变温的关系。发现在极夜期间 ,臭氧含量与 5 0 h Pa风速存在较好的相关性。根据热成风原理 ,计算了极夜期间的温度平流项 ,发现臭氧含量与 5 0 h Pa温度平流也存在一定的相关性 ,变温 ΔT的变化主要是由温度平流引起的。平流层臭氧只具有微弱的加热效应  相似文献   

Palaeomagnetism of the Stephano-Autunian Lower Tiguentourine formations from stable Saharan craton (Algeria)   总被引：1，自引：0，他引：1  

Mohamed El-Messaoud Derder  Bernard Henry  Nacer-Eddine Merabet  Lucien Daly 《Geophysical Journal International》1994,116(1):12-22

  相似文献   

南极中山站附近麦氏贼鸥雏鸟生长及其影响因素          下载免费PDF全文

王自磐 《极地研究》1994,6(1):28-37

在１９８９／１９９０年度南极夏季，对中山站附近麦氏贼鸥雏鸟的生长进行了观察和研究。本区麦氏贼鸥育雏期大约在每年１２月中旬至翌年２月下旬，雏鸟的成活率较低，本年度为３８．９％，从出雏到育成（首飞日），育期平均５３．２天（范围５２－５５天）。雏鸟平均体重日增长率，第一雏鸟为２７．４２ｇ／ｄ，第二雏鸟为１６．５６ｇ／ｄ。雏鸟生长的逻辑斯蒂克曲线数学方程式为：Ｗ＝１２５５．４１＋２２．６０３４ｅ－０．１５１８ｔ（第一雏鸟）生长曲线渐近线为１２５５．４ｇ，拐点为２０．５ｄ，第一雏鸟体重的最大日增率ｘ＝４３．９４±８．２４（ｇ）。影响本区麦氏贼鸥雏鸟生长和成活率的主要外部因子是天气（如暴风雪）同类自残以及食物等  相似文献   

华北地台南缘熊耳山地区前寒武纪古地磁研究     

王官福  丁士应  陈志宏  任富根  张金起 《物探与化探》1994,18(2):104-112

本文通过对熊耳山地区所出露的前寒武纪主要地层的古地磁研究,初步建立了该地区前寒武纪古地磁的视极移路径,并与华北地台已有的前寒武纪古地磁结果进行对比,讨论了它们的相互关系。  相似文献