Physics of auroral phenomena : proceedings of the 35th Annual seminar, Apatity, 28 Februaru – 02 March, 2012 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2012. - 187 с. : ил., табл.

“P h y sics o f A u roral P h en om en a ", Proc. X X X V A n n u al Sem inar, A p a tity, p p . 1 2 3 -1 2 6 , 2 0 1 2 © Kola Science Centre, Russian Academy o f Science, 2012 Polar Geophysical Institute GLOBAL DISTRIBUTION OF AURORAL PROTON PRECIPITATION INFERRED FROM THE DMSP DATA O.I. Yagodkina, V.G. Vorobjev (Polar Geophysical Institute, Apatity, Murmansk region) Abstract. For the further development of the Auroral Precipitation Model (http://apm.pgia.ruy) , which yields global patterns of electron precipitation, the global model of ion (proton) precipitation is developed by using the same database of DMSP F6 and 7 spacecraft. Global distributions of the average precipitating proton energy and proton energy flux in the different MLT sectors were simulated in dependence on the magnetic activity expressed by AL and Dst. It is shown that maximum of the proton energy flux occurs in the afternoon (15-18 MLT) in DAZ, where at AL= -1000 nT the proton flux exceeds the electron one in ~3.5 times. In AOP the value of the proton flux decreases with the increasing of magnetic activity. The maximum of proton energy is registered in AOP during daytime hours of MLT. In DAZ the maximum of proton energy is observed in the afternoon. It is shown a good correlation of the calculated and observed by DMSP F6, F7 and F9 precipitation patterns during two strong magnetic storms of February 8-9, 1986, and March 13-14, 1989 with Dst =— 300 and — 600 nT, respectively. The model will allow us to calculate the total ionosphere conductivities and total precipitation power depending on the magnetic activity level. Introduction The features of the ion (proton) precipitation and the global pattern of the energy proton input were examined by many researches. Studies based on particle and optical measurements (Akasofu, 1974; Feldstein and Galperin, 1985; Hardy et al., 1989; Gussenhoven et al., 1987) have shown the existence of a region of diffuse aurora (ion precipitation) equatorward of the discrete aurora (electron precipitation) in the dusk-midnight sector. The first statistical model of auroral ion precipitation was published by Hardy et al., 1989. In their investigations the global proton precipitation patterns have been statistically described as a function of the Kp geomagnetic index based on several years of ion energy spectra measurements by the DMSP satellites. They indicate that the maximum energy flux occurs in С-shaped regions symmetric about a meridian running pre-noon to pre-midnight. In comparison to the DMSP statistical electron precipitation data (Hardy et al., 1985), the statistical proton oval is displaced equatorward of the electron oval in the afternoon and pre-midnight sectors, although some overlap is frequently observed. As a result, the model was presented in the plots of selected isocontours of the integral number flux and average energy as a function of magnetic local time and corrected geomagnetic latitude for Kp-index. Studies of Basu et al., 1987; Senior et al., 1987; Lilensten and Galand, 1998, relying on incoherent scatter radar measurements and simultaneous satellite observations showed that protons were the main source of ionization in afternoon and pre-midnight sectors at the equatorial edge of the auroral oval. Investigations of the morphology and dynamics of the proton aurora with SI 12 images (Immel et al., 2002; Burch et al., 2002) have revealed the presence of detached subauroral proton arcs in the afternoon and dusk sectors of the Northern Hemisphere under changing interplanetary magnetic field (IMF) conditions. Remote sensing of the proton aurora characteristics from IMAGE-FUV was examined by Bisikalo et al., 2003. According to their investigation the proton precipitation in proton-dominated auroral structures frequently observed in the afternoon and pre-midnight sectors at the latitudes equatorward of the auroral oval. They belong to two categories of proton auroral features: (i) hydrogen arcs known to occur in the evening sector equatorward of the electron oval and (ii) detached proton arcs observed with IMAGE-FUV in the afternoon sector following changes in orientation of the interplanetary magnetic field. Our results are based at the immediate data using DMSP F6 and F7 spacecraft observations of the average ion energy and energy fluxes in different precipitation regions. In order to investigate the ion (proton) characteristics, we have used early our created the Auroral Precipitation Model (http://apm.pgia.ru/) which allows to receive boundary locations of different types of auroral precipitation at the different levels of magnetic activity (AL and Dst indexes) and will also to receive the planetary picture of average proton energies and fluxes in different precipitating zones. Data used and analysis To carry out studies o f the characteristics of precipitating protons within two auroral regions (DAZ - the diffuse auroral zone and AOP - the auroral oval precipitation), we used a database of the data from the DMSP F6 and DMSP F7 spacecraft over an entire year (1986), including approximately 35 000 passes in all sectors of local geomagnetic time. The following boundary locations were used: on the nightside in the DAZ region the proton energy input was determined between b li - b2i boundaries where b li is the ‘zero-energy’ proton boundary; b2i is the point where the energy flux o f protons above 3 keV has a maximum; the AOP region is divided on the equatorward (b2i - b4s) and the poleward (b4s-b5i) areas. The b4s is the structured/unstructured boundary, based on the running average of correlation coefficients between individual electron spectra and their neighbors. The b5i is 123