Posted on July 24, 2022
3 Discussion and you may Results
Really empirical magnetopause patterns imagine a broad family relations between the solar wind dynamic pressure and also the magnetopause standoff length step one, in which N remains lingering for everybody solar power wind requirements. Regarding phony works, i changes only one solar breeze plasma parameter, possibly this new density otherwise acceleration, getting the exact same action-particularly develops about vibrant stress in the two cases. I result in the simulations having northward and you can southward IMF and you can determine the power legislation directory Letter. I examine numerous systems of the SWMF and you can LFM-Mix activities acquire comparable style for everybody models just like the said lower than.
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 Bz 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 Bz 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 observable difference in the magnetic field at geosynchronous orbit with a smaller |B| corresponding to a larger VSW. 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 RSandwich by the Shue et al. ( 1997 ) model and obtained that the model underestimates RSandwich 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.
Inside our works, we only use MHD simulations and make operates into the artificial solar wind requirements. Yet not, we believe that MHD habits duplicate fairly well the fresh magnetopause standoff point to own regular solar power breeze criteria (Samso ). I allowed that this really works can assist regarding development of future empirical magnetopause habits. One of several forthcoming objectives that studies variations of the dayside magnetopause is the Solar power Wind Magnetosphere Ionosphere Link Explorer (SMILE) (Raab mais aussi al., 2016 ). Using Laugh, i will be able to get a continuing time group of the latest magnetopause standoff length https://www.datingranking.net/pl/pussysaga-recenzja/ to own adjustable solar wind conditions and get examine possible empirical models.
So it works are achieved utilising the SWMF/BATSRUS gadgets arranged from the College out of Michigan Cardio getting Space Environment Acting and LFM-Mix model readily available through the NASA Community Paired Acting Heart ( In particular, i made use of consequence of brand new operates Andrey_Samsonov_072419_(1-4). A good. An effective. S. and you can Grams. B. R. admit support in the British Area Department less than Give ST/R002258/step one. Y. V. B. are backed by brand new STFC RAL Area IHR give.