Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science最新文献

{"title":"Photochemical activity over the eastern mediterranean under variable environmental conditions","authors":"C.S. Zerefos ,&nbsp;K.A. Kourtidis ,&nbsp;D. Balis ,&nbsp;A. Bais ,&nbsp;B. Calpini","doi":"10.1016/S1464-1917(01)00045-9","DOIUrl":"10.1016/S1464-1917(01)00045-9","url":null,"abstract":"<div><p>The present paper presents some of the results from the EU-funded Photochemical Activity and solar Ultraviolet Radiation (PAUR) and Photochemical Activity and solar Ultraviolet Radiation Modulation Factors (PAUR II) projects that are relevant to the photochemistry of the Eastern Mediterranean under variable conditions. Compared to S-SW flows, northern flows result in higher ozone values above the PBL. Usually during N flow the aerosol optical depth is also lower, thus resulting in higher NO₂ photodissociation rates. In one case of northern flow, the Etesian synoptic regime, N-NE flows are associated with high wind speeds and result to even lower aerosol optical depth. S-SW flow during springtime in some cases brings air loaded with Saharan dust particles over the region that is poor in tropospheric ozone and precursors. Often, these cases are associated with southern stratospheric circulation, resulting in reduced total ozone amounts and hence increased ozone photolysis rates, whereas the dust load reduces nitrogen dioxide photolysis rates. Results are presented from a spectral radiation model, which simulates the spectral UV radiation during some of the above cases. Measurement results from the Athens basin and rural Aegean sites are presented, that compare the ozone levels between normal N flow conditions and Etesian flow.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 7","pages":"Pages 549-554"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)00045-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79219203","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}

{"title":"Electromagnetic signals of a seismic excitation of geolocal structures beneath a sea bottom","authors":"S.V. Ershov ,&nbsp;I.B. Mikhaylovskaya ,&nbsp;O.B. Novik","doi":"10.1016/S1464-1917(01)95022-6","DOIUrl":"10.1016/S1464-1917(01)95022-6","url":null,"abstract":"<div><p>We formulate a mathematical model of generation and propagation of seismo-electromagnetic (EM) signals in the basin of a marginal sea with an arbitrary 2D geological structure of the bottom, including the transfer of seismic and EM energy from lithosphere to hydrosphere and EM emission into atmosphere. In case of a model basin which is a 2D scheme of the central part of the basin of the Sea of Japan, the first magnetic signal is generated in the conductive (0.02 S/m) upper mantle layer M where weak seismic displacements (SD) are supposed to arise at the moment <em>t</em> = 0. The amplitude and duration of a SD were of order of a few centimetres and a few seconds and differ in different simulations. The primary signal from M with the amplitude about 50 pT reaches for the sea bottom at the moment <em>t</em> = 3.5 sec. Magnetic diffusion into the conductive sea water is too slow and thus EM signal in atmosphere originates due to geomagnetic field induction in the vertically moving water column Q_s located above the area of the initial contact of the seismic P wave (from M) with the sea bottom. Because of the structure of the seismo-hydrodynamic field and the EM field conjugation conditions at the sea-atmosphere interface the horizontal component <em>B₂</em> of the seismo-hydrodynamic magnetic field is being generated, at first, in a thin water layer under the top of <em>Q</em>_s at the sea surface, whereas the vertical component <em>B</em>₁ is being generated everywhere in <em>Q</em>_s. After the spreading of the magnetic signals, <em>B</em>₁ is up to 250 and 150 pT at the sea surface and at the height of 10 km respectively at <em>t</em> = 10 sec Magnetic signals are represented by oscillations of the same low frequency range (0.1 to 10 Hz) as the SD. The computed long hydrodynamic wave's amplitude, caused by the SD, is not more then 20 cm. Therefore the waves transferring seismic energy can be discovered far from the coast by low-frequency EM observations.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 10","pages":"Pages 761-768"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)95022-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80749105","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}

{"title":"Ionospheric total electron content behaviour during November 1997 storm","authors":"L.W. Baran ,&nbsp;I.I. Ephishov ,&nbsp;I.I. Shagimuratov","doi":"10.1016/S1464-1917(01)00010-1","DOIUrl":"10.1016/S1464-1917(01)00010-1","url":null,"abstract":"<div><p>The GPS observations carried out by IGS stations were used to study TEC changes on global scale during storm on 22 November 1997. We analysed the spatial and temporal TEC changes through time series at selected sites and maps for different sectors of northern hemisphere in comparison with the quiet TEC variations. The positive effect in the behaviour of TEC during the storm was prevailed on global scale at middle latitudes. The strong negative effect was observed at auroral and subauroral latitudes only over America. TEC behaviour on first stage of storm was similar to TEC development of storm on 10 January 1997. The long positive effect is the significant feature in viewed storm, which is probably due to the long duration and complex development of the storm.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 5","pages":"Pages 341-345"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)00010-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81323797","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}

{"title":"Tail pressure release through auroral acceleration","authors":"E.M. Blixt ,&nbsp;J. Vogt","doi":"10.1016/S1464-1917(00)00109-4","DOIUrl":"10.1016/S1464-1917(00)00109-4","url":null,"abstract":"<div><p>Earthward convecting plasma has to circumvent the Earth on its way from the tail reconnection region to the dayside magnetosphere. This leads to radially sheared flows between the corotating plasmasphere and the low-latitude boundary layer. Consequently, embedded magnetic field lines also become sheared and set-up field-aligned currents which must close in the highly conducting auroral ionosphere. Associated electric fields and plasma motions are relatively small, the auroral ionosphere thus exerts a drag on the magnetic flux tubes embedded in the magnetospheric plasma which in turn affects the pressure distribution in the equatorial magnetosphere. We investigate the role of parallel potential drops in the acceleration region in this context with the help of a steady convection model. Parallel potential drops provide a means to decouple the magnetosphere from the ionosphere, thus they can reduce ionospheric drag to avoid high pressure build-up tailward of the Earth. Relationships between field-aligned currents, pressure gradients, and parallel potential drops are derived and compared with observations. In particular, the current-voltage relationship allows for a determination of the field-aligned resistance which is in good agreement with others estimates.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 1","pages":"Pages 207-212"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(00)00109-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84428202","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}

{"title":"A new computer model for the evaluation of data from acoustic Doppler current profilers (ADCP)","authors":"M. Adler,&nbsp;U. Nicodemus","doi":"10.1016/S1464-1917(01)95014-7","DOIUrl":"10.1016/S1464-1917(01)95014-7","url":null,"abstract":"<div><p>The knowledge of discharge is essential for the solution of technical problems and scientific questions in hydrology and water resources management. Current and streamflow data are needed for low-flow and flood forecasting, water-resources management, water quality assessment, river ecology and morphology, climate research, flood protection, and hydropower generation. The example of the acoustic Doppler equipment (ADCP) proves that an increasing demand for current and discharge data can be met at fairly low cost compared with conventional methods. The German Federal Institute of Hydrology (<em>BfG</em>) developed a software package called MISSING LINK, which offers advanced possibilities for visualisation and evaluation of streamflow data acquired with ADCPs.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 10","pages":"Pages 711-715"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)95014-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83089550","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}

{"title":"Energetic tail evolution of auroral electron spectra","authors":"M.P. Leubner","doi":"10.1016/S1464-1917(00)00091-X","DOIUrl":"https://doi.org/10.1016/S1464-1917(00)00091-X","url":null,"abstract":"<div><p>Based on a Fokker-Planck formalism a mechanism is presented, generating consistent with spacecraft observations a high energy tail electron population from the interaction of a broad-band Alfvén wave spectrum under auroral plasma conditions. The structure of the resulting suprathermal tails of the electron velocity space distributions is shown to be well represented by the family of kappa distributions, hence providing a physical interpretation of the origin of auroral energetic electron observations.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 1","pages":"Pages 61-64"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(00)00091-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91749823","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}

{"title":"Some purposes and methods of the satellite measurements of the ignorospheric response on the solar flares","authors":"S.V. Avakyan","doi":"10.1016/S1464-1917(00)00118-5","DOIUrl":"10.1016/S1464-1917(00)00118-5","url":null,"abstract":"<div><p>The paper describes methods for measuring of the response of the ignorosphere to solar flares including small tethered systems. The small tethered satellites are very suitable for the following experiments: 1. Measurements of the high ionospheric photoelectron and Auger electron spectra because there is no large shadow effect from the satellite body at large pitch-angles and also parasitic photoelectron fluxes from the satellite body are small. 2. Measurements of the increase in emissions of the upper atmosphere and the investigation of the relationship between satellite glow and its altitude and dimensions. 3. Measurements of the increase in the electron and ion densities including optical and mass-spectrometric recording of the double charged positive ions which are formed due to Auger effect at the altitudes of ignorosphere.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 4","pages":"Pages 259-263"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(00)00118-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79789813","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}

{"title":"Electrodynamic tether system-possibility of realization","authors":"V. Korepanov,&nbsp;F. Dudkin","doi":"10.1016/S1464-1917(00)00121-5","DOIUrl":"10.1016/S1464-1917(00)00121-5","url":null,"abstract":"<div><p>The tether systems are very attractive for space activity. They may be used for maintaining the large fixed distances between basic satellite and subsatellites with a variety of scientific instruments. The problem of such systems application to lower ionospheric layers measurements and electrodynamic objectives is discussed. It is shown that the application efficiency of long or extra-long tethered systems for space experiments both for instrumentation delivery to the lower ionosphere and for different electrodynamic purposes is very low. Moreover in spite of small radius the great length of the tethering rope has big interacting surface with tiny particles floating in the space. So the collision probability of the tether with such particles is rather high that can cause soon the rope break.</p></div>","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 4","pages":"Pages 281-283"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(00)00121-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79999812","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}

{"title":"Influence of infrasonic waves on the ionosphere","authors":"V.M. Krasnov ,&nbsp;Ya.V. Drobzheva","doi":"10.1016/S1464-1917(01)00026-5","DOIUrl":"https://doi.org/10.1016/S1464-1917(01)00026-5","url":null,"abstract":"","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 6","pages":"433-437"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)00026-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72243043","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}

{"title":"A long-term comparison of saskatoon MF radar and collm LF D1 mesosphere-lower thermosphere wind measurements","authors":"Ch. Jacobi ,&nbsp;M. Lange ,&nbsp;D. Kürschner ,&nbsp;A.H. Manson ,&nbsp;C.E. Meek","doi":"10.1016/S1464-1917(01)00023-X","DOIUrl":"https://doi.org/10.1016/S1464-1917(01)00023-X","url":null,"abstract":"","PeriodicalId":101026,"journal":{"name":"Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science","volume":"26 6","pages":"419-424"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1917(01)00023-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72243045","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}