Journal of Atmospheric and Terrestrial Physics最新文献_第4页

Statistical mechanisms and thermodynamics, PC version 统计机制和热力学，PC版

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(96)80450-8

M.J. Rycroft

引用次数: 1

Temporal variations of the global lightning activity deduced from the Schumann resonance data 从舒曼共振资料推断的全球闪电活动的时间变化

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00189-1

A.P. Nickolaenko , M. Hayakawa , Y. Hobara

引用次数: 25

A provisional long mean air temperature series for Armagh observatory 阿马天文台的临时长期平均气温序列

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00148-4

C.J. Butler, D.J. Johnston

引用次数: 18

The phase relationships of the ionospheric signatures of Pc1 geomagnetic pulsations Pc1地磁脉动电离层特征的相位关系

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00183-2

P.R. Sutcliffe , M.J. Jarvis

引用次数: 2

Neutral density cells in the high latitude thermosphere—2. Mechanisms 高纬度热层中的中性密度电池- 2。机制

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00166-2

J. Schoendorf , G. Crowley , R.G. Roble

{"title":"Neutral density cells in the high latitude thermosphere—2. Mechanisms","authors":"J. Schoendorf , G. Crowley , R.G. Roble","doi":"10.1016/0021-9169(95)00166-2","DOIUrl":"10.1016/0021-9169(95)00166-2","url":null,"abstract":"<div><p>NCAR-TIGCM simulations predict mesoscale cellular structures in the high latitude neutral density at altitudes from 120–350 km. During magnetically active conditions, the density structure at 200 km consists of low-density cells near dawn and dusk and high-density cells near noon and midnight. Mechanisms causing the structured density cells are a result of thermosphere-ionosphere coupling and can be explained in terms of dynamic meteorology. For example, at high latitudes ion drag causes the neutral circulation to flow cyclonically in the dawn sector and anticyclonically in the dusk sector. Low densities are contained within the cyclonic circulation at all altitudes. Below about 170 km, the densities inside the anticyclonic flow are high, while above that altitude densities within the anticyclonic flow are low. While typical dynamic meteorology explains low densities in the centre of cyclonic circulation and high densities inside anticyclonic circulation, the dusk low-density cell in the centre of anticyclonic flow is unexpected. The anticyclonic dusk low-density cell is explained by anomalous antibaric flow due to high-speed winds. 120 km and 200 km altitudes are used to demonstrate the relationship between the high latitude densities and winds as well as the effect of joule heating and auroral particle precipitation on the density structures.</p></div>","PeriodicalId":100754,"journal":{"name":"Journal of Atmospheric and Terrestrial Physics","volume":"58 15","pages":"Pages 1769-1781"},"PeriodicalIF":0.0,"publicationDate":"1996-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9169(95)00166-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53072293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

Plasmaspheric zonal electric fields and coupling fluxes from the Dunedin VLF Doppler experiment, for 180°E, L ≈ 2.3, at solstice and equinox 达尼丁VLF多普勒实验在180°E, L≈2.3时的等离子体层纬向电场和耦合通量

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00185-9

H.F. Balmforth, N.R. Thomson

{"title":"Plasmaspheric zonal electric fields and coupling fluxes from the Dunedin VLF Doppler experiment, for 180°E, L ≈ 2.3, at solstice and equinox","authors":"H.F. Balmforth, N.R. Thomson","doi":"10.1016/0021-9169(95)00185-9","DOIUrl":"10.1016/0021-9169(95)00185-9","url":null,"abstract":"<div><p>Group delays and Doppler shifts from ducted whistler-mode signals are measured using the VLF Doppler experiment at Dunedin, New Zealand (45.8°S, 170.5°E). Equatorial zonal electric field and plasmasphere-ionosphere coupling fluxes are determined for <em>L</em> ≈ 2.3 at June solstice and equinox during magnetically quiet periods. The general features of the electric field measured at Dunedin agree with those predicted from ionospheric dynamo theory with a (1,−2) tidal component. Some seasonal variations are observed, with the electric field measured during equinox being smaller and predominantly westward during the night. The electric field at June solstice is also westward during the evening and for part of the night, but turns sharply eastward during the pre-dawn and dawn period at the duct entry site. The June electric field appears to follow a diurnal variation whereas the equinox electric field shows a possible 4-hourly periodic variation. Seasonal variations in the neutral wind pattern, altering the configuration of the ionospheric dynamo field, are the probable cause of the seasonal differences in the electric field. The seasonal variation of the coupling fluxes can be explained by the alteration of the <strong>E</strong> x <strong>B</strong> drift pattern, caused by the changes in the electric field.</p></div>","PeriodicalId":100754,"journal":{"name":"Journal of Atmospheric and Terrestrial Physics","volume":"58 15","pages":"Pages 1793-1804"},"PeriodicalIF":0.0,"publicationDate":"1996-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9169(95)00185-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53072864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Space environment: Implications for spacecraft design 空间环境:对航天器设计的启示

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(96)80445-4

M.J. Rycroft

引用次数: 12

Computational electrodynamics, the finite-difference time-domain method 计算电动力学，时域有限差分法

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(96)80449-1

M.J. Rycroft

引用次数: 224

Neutral density cells in the high latitude thermosphere—1. Solar maximum cell morphology and data analysis 高纬度热层的中性密度电池- 1。太阳极大期电池形态及数据分析

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(95)00165-4

J. Schoendorf , G. Crowley , R.G. Roble , F.A. Marcos

{"title":"Neutral density cells in the high latitude thermosphere—1. Solar maximum cell morphology and data analysis","authors":"J. Schoendorf , G. Crowley , R.G. Roble , F.A. Marcos","doi":"10.1016/0021-9169(95)00165-4","DOIUrl":"10.1016/0021-9169(95)00165-4","url":null,"abstract":"<div><p>A new high latitude thermospheric neutral density structure has been revealed in NCAR-TIGCM simulations at 120–350 km altitude. The structure consists of density cells above 50° latitude with radii of approximately 1000 km. There are between two to four cells present depending on the altitude and magnetic activity. For example, at 200 km under magnetically active conditions, the density structure consists of four cells: low density cells are located near dawn and dusk and high density cells are located near noon and midnight. Density variations among the cells range from 5 to 50% for magnetically quiet and active conditions respectively. The cells are present at all seasons, for a wide range of magnetic activity levels, and at solar minimum and solar maximum. The density cell morphology is established for equinox solar maximum as a function of altitude and magnetic activity. Departures of the cell structure from this morphology due to seasonal and solar cycles are discussed. The cell morphology provides a new framework in which to interpret lower thermospheric density data. Data to test and confirm the model predictions were provided by the SETA-1 satellite.</p></div>","PeriodicalId":100754,"journal":{"name":"Journal of Atmospheric and Terrestrial Physics","volume":"58 15","pages":"Pages 1751-1768"},"PeriodicalIF":0.0,"publicationDate":"1996-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9169(95)00165-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53072280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 27

Recipe for predicting the IMF Bz polarity's change of direction following solar disturbances and at the onset of geomagnetic storms 预测国际货币基金组织Bz极性在太阳扰动和地磁风暴开始时方向变化的配方

Journal of Atmospheric and Terrestrial Physics Pub Date : 1996-11-01 DOI: 10.1016/0021-9169(96)00010-4

Chin-Chun Wu , Murray Dryer , Z. Smith , S.T. Wu , L.H. Lyn

{"title":"Recipe for predicting the IMF Bz polarity's change of direction following solar disturbances and at the onset of geomagnetic storms","authors":"Chin-Chun Wu , Murray Dryer , Z. Smith , S.T. Wu , L.H. Lyn","doi":"10.1016/0021-9169(96)00010-4","DOIUrl":"10.1016/0021-9169(96)00010-4","url":null,"abstract":"<div><p>A three-dimensional, time-dependent, MHD model of solar-disturbance-caused storms (Wu, 1993; Wu <em>et al.</em>, 1996a) is used to predict the turning direction of the interplanetary magnetic field (IMF) at Earth. More explicitly, we examine the polarity of <em>B</em><sub>z</sub> caused by solar disturbances on the Sun. Three manifestations of solar disturbances, as studied by previous workers, are examined. Firstly, twenty-nine kilometric Type II events, associated (Cane, 1985) with geomagnetic storms, are studied within the context of our three-dimensional model. Then, an additional eleven long-duration X-ray events (LDEs) with radio fluxes greater than 100 solar flux units were examined; these events were not associated with interplanetary Type II events but were also associated (Cane, 1985) with geomagnetic storms. Finally, <em>in situ</em> interplanetary phenomena that caused ten large (<em>Dst</em> < −100 nT, the intensification of the storm) geomagnetic storm episodes (Tsurutani <em>et al.</em>, 1988) near solar maximum are also studied via the <em>B</em><sub>z</sub> predictions of our 3D MHD model. The accuracy of these <em>B</em><sub>z</sub> turning-direction-predictions is found to be as follows: (1) for the kilometric Type II events, the model's prediction was successful for 26 of the 29 events studied; (2) 10/11 for the LDE events; and (3) 7/9 for the major geomagnetic storm events. The overall prediction accuracy of these three independent data sets is 43/49. Thus, consideration of these three independent data sets strongly suggests that the recipe proposed by the basic 3D MHD model may be valid for a zero-th order prediction scheme.</p></div>","PeriodicalId":100754,"journal":{"name":"Journal of Atmospheric and Terrestrial Physics","volume":"58 15","pages":"Pages 1805-1814"},"PeriodicalIF":0.0,"publicationDate":"1996-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9169(96)00010-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53072986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7