We make several MHD works to evaluate which presumption

step three Discussion and you can Results

Really empirical magnetopause habits imagine a broad family between the solar power cinch dynamic stress in addition to magnetopause standoff length 1, where N stays constant for everyone solar power wind standards. From the fake operates, we alter singular solar cinch plasma parameter, both the brand new thickness otherwise velocity, having the exact same step-instance expands regarding the active stress in the two cases. We make the simulations for northward and southward IMF and you may estimate the advantage legislation directory N. We compare several versions of SWMF and you will LFM-Merge activities acquire equivalent fashion for everybody activities once the told me below.

Our results also show that the increase in the ionospheric conductivity or the use of a model with the additional inner magnetosphere-ionosphere block result in decrease in N. Therefore, we cannot derive a single N from the MHD simulations because the dispersion in N between the models is large; however, all models predict the same changes between different runs related to the density and velocity increases, and B_z sign.

The simulations we present suggest that dayside magnetopause reconnection influences the magnetic field magnitude at geosynchronous orbit near subsolar point. We obtain different geosynchronous magnetic fields in northward and southward IMF runs with the same dynamic pressure. Moreover, the magnetic field magnitude is also different when comparing the runs in which both the dynamic pressure and B_z are kept the same and only the ratio between the solar wind ? and V is different. Increasing velocity instead of density for a southward IMF, we increase the magnetopause reconnection rate and this results in an jak sprawdzić, kto cię lubi w hongkongcupid bez płacenia observable difference in the magnetic field at geosynchronous orbit with a smaller |B| corresponding to a larger V_SW. Similar variations at geosynchronous orbit are observed in northward/southward turning events with a constant solar wind dynamic pressure (Samso ).

Our results partly agree with the results in Nemecek et al. ( 2016 ). We find that an increase in the ionospheric conductivity causes stronger variations of the magnetopause standoff distance, but, contrary to Nemecek et al. ( 2016 ), an increase in the solar wind velocity may also enhance variations of the standoff distance. However, we cannot compare our results with Nemecek et al. ( 2016 ) directly. Nemecek et al. ( 2016 ) normalized observed R_Sub by the Shue et al. ( 1997 ) model and obtained that the model underestimates R_Sub for high velocities. First, we note that it would agree with a numerical model for which N>6.6 since N=6.6 in Shue et al. ( 1997 ). Second, variations of the solar wind velocity cannot be treated independently in the observations, they correlate with variations of the magnetic field (Owens & Cargill, 2002 ), and even (on a large time scale) with the ionospheric conductivity because higher velocities are usually observed at solar maximum. Therefore, it is difficult to make a straightforward conclusion from these results.

Within performs, i just use MHD simulations and also make operates with the phony solar breeze standards. But not, we think you to MHD designs replicate reasonably really the magnetopause standoff distance to have regular solar power piece of cake standards (Samso ). We allowed this works will assist regarding development of future empirical magnetopause activities. Among the many imminent objectives that’ll investigation differences of your own dayside magnetopause ‘s the Solar Breeze Magnetosphere Ionosphere Link Explorer (SMILE) (Raab ainsi que al., 2016 ). Playing with Smile, we will be capable receive a continuing big date a number of this new magnetopause standoff distance getting adjustable solar cinch conditions and possess confirm prospective empirical models.

Acknowledgments

Which functions are accomplished with the SWMF/BATSRUS systems put up from the School away from Michigan Cardiovascular system for Space Ecosystem Acting while the LFM-Blend model available from the NASA Community Matched up Acting Heart ( Particularly, i used outcome of the new runs Andrey_Samsonov_072419_(1-4). An excellent. A beneficial. S. and you can Grams. B. Roentgen. admit help throughout the British Space Company less than Grant ST/R002258/step 1. Y. V. B. was supported by the fresh STFC RAL Area IHR give.