On the low latitude ''negative bays'' in the afternoon sector

Polar electrojet and simultaneous geomagnetic disturbances on poleward side of auroral zone simultaneous with positive bay observations in auroral zon

The auroral oval, the auroral substorm, and their relations with the internal structure of the magnetosphere

Interaction between ring current and neutral sheet causing magnetospheric instability and changes in polar auror

Auroral effects in the D region of the ionosphere

The possible effects are discussed of radiations and corpuscles on relatively short-term changes in the circulation of the atmosphere (the development of cellular patterns in the zonal westerly flow, leading to the formation of cyclones) and relatively long-term changes in climate

The Development of the Forbush Decrease and the Geomagnetic Storm Fields

Relationships between Forbush decreases and associated geomagnetic storm characteristic

Solar wind disturbances in th outer heliosphere caused by successive solar flares from the same active region

Solar wind disturbances caused by successive flares from the same active region are traced to about 20 AU, using the modeling method developed by Hakamada and Akasofu (1982). It is shown that the flare-generated shock waves coalesce with the co-rotating interaction region of the interplanetary magnetic field, resulting in a large-scale magnetic field structure in the outer heliosphere. Such a structure may have considerable effects on the propagation of galactic cosmic rays

The structure of the solar plasma flow generated by solar flares

Geomagnetic storm characteristics for two-dimensional configuration of solar plasma flow generated by solar flare

Auroral kilometric radiation/aurora correlation

Auroral kilometric radiation (AKR) observations from the ISIS 1 topside sounder receiver were compared with visual auroral observations from the network of Alaskan all-sky camera stations. The goal was to relate AKR source region encounters to specific auroral forms on the same magnetic field line. Thirty-eight simultaneous data sets were identified and analyzed. In general, intense AKR was associated with bright auroral arcs and conditions of weak or no AKR corresponded to times when either no aurora or only a faint arc or weak diffuse aurora were observed. Five cases, when both intense AKR and bright visual aurora were present, were analyzed in detail. Complete electron density N sub e contours, from the satellite altitude down to the F region ionization peak, were obtained along N-S traversals of the AKR source region. In addition, the ISIS 1 orbital tracks were projected down the magnetic field lines to the auroral altitude and compared to auroral features on a map derived from the all sky camera images. Density cavities (regions where N sub e 100/cu cm) were encountered on each of these passes

A simulation study of two major events in the heliosphere during the present sunspot cycle

The two major disturbances in the heliosphere during the present sunspot cycle, the event of June to August, 1982, and the event of April to June, 1978, are simulated by the method developed by Hakamada and Akasofu (1982). Specifically, an attempt was made to simulate the effects of six major flares from three active regions in June and July, 1982, and April and May, 1978. A comparison of the results with the solar wind observations at Pioneer 12 (approximately 0.8 au), ISEE-3 (approximately 1 au), Pioneer 11 (approximately 7 to 13 au) and Pioneer 10 (approximately 16 to 28 au) suggests that some major flares occurred behind the disk of the sun during the two periods. The method provides qualitatively some information as to how such a series of intense solar flares can greatly disturb both the inner and outer heliospheres. A long lasting effect on cosmic rays is discussed in conjunction with the disturbed heliosphere

The photodisintegration of cosmic ray nuclei by solar photons: the Gerasimova-Zatsepin effect revisted

The interesting possibility of measuring the masses of high energy cosmic ray particles by observing pairs of extensive air showers arriving at the earth nearly simultaneously was proposed some years ago by Gerasimova and Zatsepin (1960). Such showers would be created by the nuclear fragments originating as a result of the photodisintegration of massive nuclei interacting with the solar radiation field. In this paper we re-visit this possibility in the context of existing and proposed detectors of high and ultra-high energy cosmic rays considering a simple, yet realistic, model of the interplanetary magnetic field. The possibilty of observing the mass fragmentation of cosmic rays directly, however, remains challenging.Comment: 14 pages, 7 figures (3 ps + 4 jpg), Astroparticle Physics (in press) - typos corrected and other minor modification

ツクバサンチョウ カラ ニホン ノ エイガク ヲ テンボウ スル

1 筑波山には三回ほど登った。いや、ケーブル・カーに乗っていき、山頂から下界を見下ろしたことがある。残念ながら眺望は麓の学園都市どまりであって、関東平野を一望することはできなかった。天気のせいばかりでなく、視力のせいだった。遠景と近景が同時によいというわけにはいかないらしい。 ..