Article

Thermal ion outflows at nightside polar cap on interball-2 altitudes

April 2003

Authors:

Dmitry Chugunin

Space Research Institute, Russian Academy of Sciences

An analysis of the ionospheric ion outflow at nightside of the polar cap measured on INTERBALL-2 by the HYPERBOLOID low energy mass-angle spectrometer is presented. Detailed analysis of simultaneous measurements of higher energy electron and ion intensities was performed to choose the ion flow driven only by thermal energy ionospheric plasma. The cleft ion fountain was excluded from observations. The data of the ``pure'' polar wind and other outflow types founded at chosen time are presented. Data was selected for winter and summer period for northern hemisphere. Thus the outflow when ionosphere was absolutely dark or sunlight was studied. The dependence Summer-Winter was found. Dependence of ionospheric outflow from polar rain intensities is discussed.

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Article

Characteristics of the polar wind ion flux on ~20000 km altitude

April 2009

Dmitry Chugunin

Characteristics of the polar wind ion flux on ~20000 km altitude are presented. Measurements of the ion fluxes were made by Hyperboloid instrument onboard Interball-2 satellite. Characteristics were done for ionospheric H+, He+ and O+ ion moving upward from the sunlit polar cap in the period of solar minimum. From the analysis it were excluded measurements when simultaneously high energy ion and ... [Show full abstract] electrons were detected. Cleft ion fountain ions also were excluded from the statistics. It was found with high probability that cases when only H+ ion were detected (another didn't have enough velocity value to overcome positive potential barrier) is the polar wind flux. The characteristics of that fluxes have very good correspond to several models simulations and are n~1.5 cm-3, Vpar~21 km/s, Тpar~3500 К, Tperp~2000 К. In case when also He+ and O+ ions were detected the temperatures were significantly higher modeled ones, and parallel velocity of O+ ion occurs higher model in several times.

Article

Effect of hot electrons on the polar wind

December 1984 · Journal of Geophysical Research Atmospheres

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Article

Polar Wind Observations on the Nightside of the Polar Cap at Altitudes of 2–3 RE: Results of the INT...

July 2002 · Cosmic Research

The results of measuring the fluxes of ionospheric ions in the nightside polar cap at an altitude of about 20 000 km are presented. The data are obtained with the HYPERBOLOID instrument onboard the INTERBALL-2 satellite. The passages without intense precipitation of magnetospheric ions and electrons have been selected using the ION instrument data, so that the observation of ionospheric ion ... [Show full abstract] fluxes caused by heating in the auroral regions can be excluded. In addition, an attempt has been made to exclude observations of the cleft ion fountain from the analysis. The measurements in the summer and winter seasons (when the ionosphere was totally sunlit and completely shadowed, respectively) are considered separately. By analyzing the distribution functions of the fluxes measured, we have isolated six different types of ionospheric plasma flows in the polar cap. A strong distinction has been revealed between summer and winter flows. In winter, only weak flows of H+ ions were detected. In the summer period, we detected both H+ and O+ ions. The flux values of the ionosphere ions are found to be strongly dependent on the intensity of the polar rain. The measurements are compared to the existing models of the polar wind. The best models (for the description of our measurements) are indicated. After the choice of measurement periods, the resulting region coincides with the ion depletion zone (IDZ). Based on the earlier measurements by the AKEBONO satellite, nothing could be said about the fluxes of thermal ions in this zone, because of the insufficient sensitivity of the instrument aboard this satellite.

Article

Thermal Ion Outflows At Nightside Polar Cap Measured By Hyperboloid Instrument On Interball-2 Altitu...

January 2002

An analysis of the ionospheric ion outflow at nightside of the polar cap measured on INTERBALL-2 by the HYPERBOLOID low energy mass-angle spectrometer is presented. Detailed analysis of simultaneous measurements of higher energy electron and ion intensities was performed to choose the ion flow driven only by thermal en- ergy ionospheric plasma. The cleft ion fountain was excluded from ... [Show full abstract] observations. The data of the SpureT polar wind and other outflow types founded at chosen time are & cedil;presented. Data was selected for wibnter and summer period for northern hemisphere. Thus the outflow when ionosphere was absolutely dark or sunlight was studied. From the thermal ions measurements six types of outflows were found in the polar cap. Four from them are polar wind outflow and two other are due to addition heating sources. The dependence Summer-Winter was found. Strong dependence of O+ outflow from polar rain intensities was found.