Response time of the high-latitude dayside ionosphere to sudden changes in the north-south component of the IMF

The time scale of the response of the high-latitude dayside ionospheric flow to changes in the North-South component of the interplanetary magnetic field (IMF) has been investigated by examining the time delays between corresponding sudden changes. Approximately 40 h of simultaneous IMF and ionospheric flow data have been examined, obtained by the AMPTE-UKS and -IRM spacecraft and the EISCAT “Polar” experiment, respectively, in which 20 corresponding sudden changes have been identified. Ten of these changes were associated with southward turnings of the IMF, and 10 with northward turnings. It has been found that the corresponding flow changes occurred simultaneously over the whole of the “Polar” field-of-view, extending more than 2° in invariant latitude, and that the ionospheric response delay following northward turnings is the same as that following southward turnings, though the form of the response is different in the two cases. The shortest response time, 5.5 ± 3.2 min, is found in the early- to mid-afternoon sector, increasing to 9.5 ± 3.0 min in the mid-morning sector, and to 9.5 ± 3.1 min near to dusk. These times represent the delays in the appearance of perturbed flows in the “Polar” field-of-view following the arrival of IMF changes at the subsolar magnetopause. Overall, the results agree very well with those derived by Etemadi et al. (1988, Planet. Space Sci.36, 471) from a general cross-correlation analysis of the IMF Bz and “Polar” beam-swinging vector flow data.

The dependence of high-latitude dayside ionospheric flows on the North-South component of the IMF: A high time resolution correlation analysis using EISCAT “Polar” and AMPTE UKS and IRM data

In 1984 and 1985 a series of experiments was undertaken in which dayside ionospheric flows were measured by the EISCAT “Polar” experiment, while observations of the solar wind and interplanetary magnetic field (IMF) were made by the AMPTE UKS and IRM spacecraft upstream from the Earth's bow shock. As a result, 40 h of simultaneous data were acquired, which are analysed in this paper to investigate the relationship between the ionospheric flow and the North-South (Bz) component of the IMF. The ionospheric flow data have 2.5 min resolution, and cover the dayside local time sector from ∼ 09:30 to ∼ 18:30 M.L.T. and the latitude range from 70.8° to 74.3°. Using cross-correlation analysis it is shown that clear relationships do exist between the ionospheric flow and IMF Bz, but that the form of the relations depends strongly on latitude and local time. These dependencies are readily interpreted in terms of a twinvortex flow pattern in which the magnitude and latitudinal extent of the flows become successively larger as Bz becomes successively more negative. Detailed maps of the flow are derived for a range of Bz values (between ± 4 nT) which clearly demonstrate the presence of these effects in the data. The data also suggest that the morning reversal in the East-West component of flow moves to earlier local times as Bz, declines in value and becomes negative. The correlation analysis also provides information on the ionospheric response time to changes in IMF Bz, it being found that the response is very rapid indeed. The most rapid response occurs in the noon to mid-afternoon sector, where the westward flows of the dusk cell respond with a delay of 3.9 ± 2.2 min to changes in the North-South field at the subsolar magnetopause. The flows appear to evolve in form over the subsequent ~ 5 min interval, however, as indicated by the longer response times found for the northward component of flow in this sector (6.7 ±2.2 min), and in data from earlier and later local times. No evidence is found for a latitudinal gradient in response time; changes in flow take place coherently in time across the entire radar field-of-view.

The Chandler-Furtado case: a decolonial reframing of a North/South (dis)encounter

A partir de uma perspectiva descolonial das bordas do Sul, este trabalho mostra que, apesar de Alfred Chandler e o brasileiro Celso Furtado terem muito a contribuir para a construção de um campo de estratégia multipolar, foi somente o primeiro que se tornou uma autoridade em gestão estratégica. Ao longo de mais de 50 anos Chandler e Furtado pesquisaram sobre o mesmo objeto, mas a partir de diferentes perspectivas. Contudo, defendemos que suas pesquisas são partes inseparáveis de um mesmo fenômeno, da mesma maneira que modernidade e colonialidade são, e que é necessário a descolonialidade para promover o encontro a que se propõe fazer este trabalho. Chandler defendia nos anos 60 que a grande corporação, liderada pelos gestores, era o grande motor do capitalismo americano; enquanto que no Sul, Furtado argumentava que o estado, através de planejamento e investimento, deveria liderar a saída do Brasil da condição de subdesenvolvimento, a qual lhe fora imposta principalmente pelo Norte. A crise atual da hegemonia americana sugere que devemos recuperar os argumentos de Furtado e discutir a difusão assimétrica do conhecimento e das instituições em administração na América Latina durante o período da Guerra Fria. Neste trabalho propomos uma estrutura com três níveis de análise para reavaliar este (des)encontro entre Chandler-Furtado através de perspectivas independentes: a grande narrativa da Guerra Fria, o conhecimento subalterno e a identidade nacional. Nosso objetivo é promover um mundo multipolar através dos campos da administração e gestão estratégica.

North-South trade relations in the Americas: the case for free trade

Includes bibliography

Brazil and India: two BRICs as a building bloc for South-South cooperation""

Includes Bibliography

The North-South dimension of the environmental and cleaner technology industries

Includes bibliography

Committee on South-South cooperation: provisional agenda

Includes bibliography

Committee on South-South cooperation: annotated provisional agenda

Includes bibliography

Activities of the ECLAC system to promote and support South-South cooperation during the 2004-2005 biennium. Note by the Secretariat

Includes bibliography

Activities of the ECLAC system to promote and support South-South cooperation during the 2006-2007 biennium

Includes bibliography

Committee on South-South cooperation: provisional agenda

Includes bibliography

Committee on South-South cooperation: annotated provisional agenda

Includes bibliography