Intensity maps of MeV electrons and protons below the radiation belt

Kohno, Toshitake; Munakata, K.; Nagata, K.; Murakami, Hiroyuki; Nakamoto, Atsushi; Hasebe, Nobuyuki; Kikuchi, Jun; Doke, T.

doi:10.1016/0032-0633(90)90141-c

Cited by 19 publications

(7 citation statements)

References 7 publications

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“…Different data sets having different native formats must be reformatted and associated with magnetospheric state information and to allow both data and metadata to be linked together. To construct a new prototype trapped radiation database, we have processed the data from the MEPHD instrument (Raben et al, 1995) aboard the NOAA 5-8 satellites and HEP on OHZORA (Kohno et al, 1990;Nagata et al, 1985) into CDF data files and included with each 1-min particle flux record information on solar wind density and bulk speed, IMF, and the concurrent AE, D st , K p , and F10.7 values. Using currently available CDF tools, it will be simple to include other parameters or to eliminate unneeded ones as appropriate at a later date.…”

Section: Prototype Database Developmentmentioning

confidence: 99%

Development of a magnetospheric state-based trapped radiation database

Fung¹,

Bell²,

Tan³

et al. 2005

Advances in Space Research

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At the core of any empirical trapped radiation model is a database containing energetic particle observations. The usefulness of such a database and the performance of the resulting models depend on the database flexibility to respond to queries based on differing magnetospheric conditions, and the ability to locate, select, retrieve and analyze the relevant particle data. Current empirical trapped radiation models, such as the NASA AE-8 and AP-8 models, are essentially flux lookup tables on (E; B/B 0 , L) grids based on processed data. Such lookup tables are inherently static, non-updateable, and non-extensible. Consequently, the models constructed from them would have limited performance. As an initial effort to construct a new generation of empirical trapped radiation models, a new magnetospheric state-based trapped radiation database is being constructed in order to overcome existing model limitations. We have adopted an object-oriented database design to accommodate the complex and dynamic space radiation environment. The technique encapsulates the particle data, ancillary data, and metadata into abstract objects in a common framework to handle heterogeneous data sources. The new database structure will allow users to query the database using combinations of geophysical, temporal and spatial parameters. In this paper, we will focus on the implementation issues that arise in integrating heterogeneous data sets. To mitigate against early obsolescence when updated or new data become available, the modelsÕ underlying database must be updateable and extensible. In addition, to ensure high model performance, the database must be parameterizeable, so that the selection of data from the database for analysis or modeling can vary with magnetospheric conditions or states that vary with solar wind and IMF driving conditions and geomagnetic responses (see Fung, S. F. Recent development in the NASA trapped radiation models, in: Radiation Belts:

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Section: Prototype Database Developmentmentioning

confidence: 99%

Development of a magnetospheric state-based trapped radiation database

Fung¹,

Bell²,

Tan³

et al. 2005

Advances in Space Research

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“…For comparisons with observations and the AE8 model, integral omnidirectional fluxes in units of cm-*s-l were calculated. The results of our model calculations are shown in Figures 2, 3, and 4, and are compared to fluxes from the NASA AE8-MIN model and to the OHZORA observations (Nagata et al, 1985;Kohno et al, 1990;Fung et al, 1996).…”

Section: Model Description and Initializationmentioning

confidence: 99%

Spatial distributions of the inner radiation belt electrons: A comparison between observations and radial diffusion theory predictions

Böscher

Fung

Tan

1997

Advances in Space Research

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It is well known that the quiet-time electron radiation belts exhibit a two-zone radial structure. Although the inner radiation belt does show dynamic variations during geomagnetically active periods, the stably trapped electrons found in this region are thought to be populated primarily by diffusive transport processes. Recent analyses of the long-term (1984)(1985)(1986)(1987) energetic electron (0.19-3.2 MeV) observations taken at 350-850 km altitude by the OHZORA satellite indicate that the trapped electrons also show local-time variations in pitch angle distributions. We here report the observed L-shell distributions of the energetic electrons and show that they are in good agreement with the azimuthally averaged predictions of the radial diffusion theory (the Salammbo model) for inner zone electron fluxes. We also compare the OHZORA observations with earlier observations as compiled in the NASA empirical radiation belt models.

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“…Kohno et al (1990) demonstrated global distributions of electron (0.19-3.2 MeV) and proton (0.64-35 MeV) fluxes in the SAMA by statistically analyzing data from ∼3 years of OHZORA satellite observations. The satellite-observed trapped particles had nearly 90…”

Section: Discussionmentioning

confidence: 99%

Energetic particle precipitation in the Brazilian geomagnetic anomaly during the “Bastille Day storm” of July 2000

et al. 2006

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Ionospheric absorption associated with a great geomagnetic storm on July 15-16, 2000 (the "Bastille Day storm") was observed in the Brazilian geomagnetic anomaly using a two-dimensional 4 × 4 imaging riometer (IRIS). In the afternoon of July 15, weak absorption (∼0.2 dB) was observed during the initial phase of the storm; large spatial-scale absorption exceeded the IRIS field of view (330×330 km). During the sharp magnetic decrease in the main phase of the storm, absorption was intensified (<0.5 dB) in the evening, showing a sheet structure with ∼150 km latitudinal width and >330 km longitudinal elongation. Subsequently, absorption was intensified (∼1 dB), having a small spatial-scale (∼150 km) in the background sheet structure and a pronounced westward drift (∼570 m s −1 ). In association with large magnetic fluctuations in the Bz component of the interplanetary magnetic field (IMF), the ground magnetic variation in the night sector showed large positive swings during the initial to main phases of the storm. With the subsequent southward turning of the IMF Bz, the ground magnetic variation in the evening sector showed rapid storm development. Particle fluxes measured by a geosynchronous satellite (L =∼6.6) demonstrated large enhancements of low-energy protons (50-400 keV) and probably electrons (50-225 keV) during the storm's initial phase. Particle fluxes from the low-altitude NOAA satellite (∼870 km) indicated the invasion of low-energy particles into the region of L < 2 during the main phase of the storm. These results indicate that low-energy particles injected into the outer radiation belt in association with frequent and strong substorm occurrences, were transported into the inner radiation belt through direct convective access by the storm-induced electric fields during the storm's development. These particles then precipitated into the ionosphere over the Brazilian geomagnetic anomaly. Notably, the most intense absorption could be dominantly caused by proton precipitation with energies of ∼40 keV.

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Intensity maps of MeV electrons and protons below the radiation belt

Cited by 19 publications

References 7 publications

Development of a magnetospheric state-based trapped radiation database

Development of a magnetospheric state-based trapped radiation database

Spatial distributions of the inner radiation belt electrons: A comparison between observations and radial diffusion theory predictions

Energetic particle precipitation in the Brazilian geomagnetic anomaly during the “Bastille Day storm” of July 2000

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