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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo da variabilidade da deriva vertical do plasma ionosf?rico sobre a regi?o de Natal/RN, Fortaleza/CE e Cachoeira Paulista/SP para alguns casos de tempestades magn?ticas de abril a setembro de 2000

Serafim, Cleiton Cruz 18 August 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-06T22:06:17Z No. of bitstreams: 1 CleitonCruzSerafim_DISSERT.pdf: 2617910 bytes, checksum: 72783f303b98e3db20a11f0c802eae1e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-09T00:24:52Z (GMT) No. of bitstreams: 1 CleitonCruzSerafim_DISSERT.pdf: 2617910 bytes, checksum: 72783f303b98e3db20a11f0c802eae1e (MD5) / Made available in DSpace on 2016-06-09T00:24:52Z (GMT). No. of bitstreams: 1 CleitonCruzSerafim_DISSERT.pdf: 2617910 bytes, checksum: 72783f303b98e3db20a11f0c802eae1e (MD5) Previous issue date: 2015-08-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Neste trabalho, est?o sendo apresentados os resultados da investiga??o sobre a varia??o da deriva vertical do plasma da camada F que comumente ocorre nos per?odos pr?ximos ao p?r-do-sol (entre 21UT ? 22UT), e que consiste em uma subida no per?odo do dia e uma descida no per?odo noturno da camada F sobre os munic?pios de Natal/RN (33.7? O, 5.6? S), Fortaleza/CE (38.45? O, 3.9? S) e Cachoeira Paulista/SP (45.0?O, 22.7? S). Para isso, utilizou-se dados (ionogramas) de altura virtual ( h' ) em fun??o da frequ?ncia para a camada F da ionosfera. Esses dados foram coletados por meio da ionossonda tipo CADI (Canadian Advanced Digital Ionosonde) para as cidades de Natal e Fortaleza, e pela digissonda DPS para a cidade de Cachoeira Paulista. Foram considerados apenas os dados dispon?veis de 2000, ano de solar m?ximo. Com os dados de altura virtual ( h' ) reduzidos nas frequ?ncias de 5 e 6MHz, o passo seguinte foi o c?lculo do Vz. Os resultados mostraram que a variabilidade da velocidade de deriva vertical da camada F da ionosfera em per?odos de tempestades magn?ticas est? relacionada tanto ? penetra??o de campos el?tricos quanto aos campos el?tricos do d?namo perturbado. / In this work are presented the results of research on the variation of vertical plasma drift from the F layer that commonly occurs during the period close to the going down of the sun (between 21UT - 22UT), and consisting of an increase in the F layer in time of day and a drop at night on the cities of Natal / RN (The 33.7?, 5.6? S), Fortaleza / CE (38.45? O, 3.9? S) and Cachoeira Paulista / SP (45.0?O, 22.7? S ). Thus, data was used (ionograms) virtual height t ( h' ) as a function of the frequency F for the layer of the ionosphere. These data were collected through ionossonda type CADI (Canadian Advanced Digital Ionosonde) to the cities of Natal and Fortaleza, and the Digisonde DPS to the town of Cachoeira Paulista. They considered only the data available 2000 maximum solar year. With the virtual height ( h' ) data reduced in the frequencies of 6MHz and 5MHz, the next step was to calculate. The results showed that the variability of the vertical drift rate F ionospheric layer periods of magnetic storms is related both to the penetration of the electric fields as the disturbance dynamo electric fields.
2

Efeito da maré lunar na região F da ionosfera

Tsali-Brown, Vera Yesutor 28 February 2018 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2018-04-03T16:10:37Z No. of bitstreams: 1 PDF - Vera Yesutor Tsali-Brown.pdf: 30843412 bytes, checksum: 59e10df34146975cb54cee13f06cba2b (MD5) / Made available in DSpace on 2018-04-03T16:10:37Z (GMT). No. of bitstreams: 1 PDF - Vera Yesutor Tsali-Brown.pdf: 30843412 bytes, checksum: 59e10df34146975cb54cee13f06cba2b (MD5) Previous issue date: 2018-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The effects of the lunar tide in the F region of the ionosphere are studied in this work using measurements provided by the ionosonde installed in Cachoeira Paulista (22 ° S, 45 ° W) between 2009 and 2011. To identify the variations associated with the lunar tides, the following parameters are used: peak height of electronic density of the F region (hmF2) and the critical frequency of the F (foF2) region. The influence of the lunar tide in the Brazilian ionosphere was obtained using the residual measurements which was without the influence of the solar tide for each day, owing that all the months were converted to the lunar time and submitted to harmonic analysis to obtain monthly amplitudes and phases for the period of study. The maximum diurnal amplitude in foF2 determined was 0.41MHz and 0.42MHz in the semidiurnal component. Also the maximum diurnal amplitude in hmF2 determined was 6.25km and semidiurnal 7.76km. The seasonal variations in the amplitudes in foF2 and hmF2 were sometimes annual and semiannual in nature. / Os efeitos da maré lunar na região F da ionosfera são estudados neste trabalho utilizando medidas fornecidas pela ionossonda instalada em Cachoeira Paulista (22° S; 45° W) entre os anos de 2009 e 2011. Para identificar as variações associadas às marés lunares são utilizados os seguintes parâmetros: altura do pico de densidade eletrônica da região F (hmF2) e a freqüência crítica da região F (foF2). A influência da maré lunar na ionosfera brasileira foi obtida utilizando as medidas residuais sem a influência da maré solar. As medidas foram convertidas para o tempo lunar e submetidas à análise harmônica para obter amplitudes e fases mensais para o período de estudo. A variação sazonal das amplitudes nos parâmetros foF2 e hmF2 foi geralmente geralmente semestral. Também eram às vezes anual

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