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Detailed Reference Information |
Trattner, K.J., Marsden, R.G. and Sanderson, T.R. (1997). The Ulysses north polar pass: Latitudinal gradients of anomalous cosmic ray O, N And Ne. Geophysical Research Letters 24: doi: 10.1029/97GL01747. issn: 0094-8276. |
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A key finding of the Ulysses mission has been the absence of large latitudinal gradients in the Anomalous Cosmic Ray (ACR) component. Studies using data from several satellites have consistently shown a small (~2%/deg.) positive latitudinal gradient for anomalous O, N and Ne in the energy range 4 to 30 MeV/n, and even smaller gradients for ACR He. In this paper we use data from the COSPIN/LET experiment on board Ulysses to investigate (a) the behaviour of the ACR latitudinal gradients during the passage over the northern polar regions, and (b) possible north-south asymmetries. The descent from the north pole has taken place under solar minimum conditions, providing a unique opportunity to study fully developed latitudinal effects. Our data survey covers three ACR species, O (4 to 20 MeV/n), N (4 to 20 MeV/n) and Ne (4 to 30 MeV/n). ACR gradients have been calculated for three different regions: 0¿--20¿ (~5%/deg.), 20¿--60¿ (~3%/deg.) and 60¿--80.2¿ (~1%/deg.). Comparison of data from the northern and southern hemisphere at a given latitude shows an asymmetry with higher fluxes in the north than in the south at a given latitude.¿ 1997 American Geophysical Union |
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Abstract |
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Keywords
Interplanetary Physics, Cosmic rays, Interplanetary Physics, Ejecta, driver gases, and magnetic clouds, Interplanetary Physics, Interstellar gas |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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