Using seemingly short (20 minute) big date times amongst the vibrant pressure methods, i implicitly assume that the changes from the magnetopause standing mainly originate from the changes in the solar power wind pressure and you will variations of the dayside job-lined up Part step 1 currents. While the magnetotail current may have a somewhat big response day, in general it merely intensifies the end result of your own Region step 1 newest. grams., some estimations have been made when you look at the Samso ); yet not, (1) new noncoupled MHD design and this show was indeed showed significantly more than do not reproduce brand new ring newest and you can (2) the time scale of one’s ring latest intensification might be even more compared to the step 3–4 hours used in these simulations. We show results of your own combined patterns below that is qualitatively just as the outcome of the newest noncoupled design, and this doesn’t alter the conclusions.
Fundamentally, we want to contrast numerous runs to confirm that our answers are design-separate. Table step one collects the advantage rules indicator Letter for the (1) calculated off half a dozen items regarding about three internationally MHD activities. The first is new noncoupled SWMF design whose abilities was basically displayed significantly more than. And the basic runs (Adaptation step 1), we simulated about three almost every other types of your own a similar noncoupled design, a few with increased ionospheric conductivity and one with a good dipole tip. This new height-incorporated Pedersen conductivity is believed becoming equivalent to 5 S throughout the newest sizes, but brands dos and you will step 3 where the provided conductivity try ten and you will 100 S correspondingly. Within the variation cuatro, we simulated this new magnetosphere that have a beneficial dipole tip 31° . Alterations in N anywhere between Types step one and you may dos and Items 1 and you may cuatro is brief, and you may between Brands 1 and you can 3 is actually reasonable, however, only for brand new southward IMF. Keep in mind that the brand new ionospheric conductivity 100 S may be very higher and you can is scarcely present in facts. We tell you they simply to teach the fresh new character off conductivity since the the two moments boost in conductivity when you look at the Type 2 transform N only for the fresh speed raise that have southward IMF.
An increase in the fresh magnetotail newest also boost in brand new Part 1 currents weakens brand new magnetospheric magnetic field and you may actions the fresh dayside magnetopause earthward
Version 5 means runs of one’s SWMF design combined with comprehensive interior-magnetosphere ionosphere, and Adaptation 6 is the LFM-Blend design. For every single type, i generate four works on northward/southward IMF and also for the occurrence and you may velocity develops because the explained more than (twenty-four operates as a whole). Remember you to definitely N=six throughout the best theoretic circumstances if your magnetopause condition suits the pressure harmony within solar power piece of cake dynamic tension and the World’s dipole industry and Letter=six.six regarding the empirical Shue et al. ( 1998 ) model. In reality, the acquired N are ranging from both of these viewpoints or some shorter. Five out-of half a dozen sizes expect N large or equivalent to eight from the operates for the occurrence increase having southward IMF. Even when Type 5 forecasts N smaller than eight, N was methodically highest in cases like this for each and every model.
Meanwhile, Tsyganenko and you may Sibeck ( 1994 ) detailed the mix-end latest plus a smaller education the fresh new ring latest along with the location step https://www.datingranking.net/pl/ifnotyounobody-recenzja/ one currents dictate the fresh new magnetic occupation for the magnetospheric area of the magnetopause
In addition to the comparison of different models, we investigate the influence of grid resolution on our results. We have calculated two runs for the same southward IMF with density and velocity changes using the noncoupled SWMF model with the 1/16 RE grid spacing around the subsolar magnetopause. We obtain different power laws, N=6.712 and 6.132, in the density and velocity runs, respectively (instead of 7.80 and 6.69 for the same model with a low resolution). Moreover, the normalized (to the solar wind electric field) reconnection rates in the low-resolution runs are smaller than those in the high-resolution runs (but are about the same in the density and velocity runs for the same resolution). We also find some differences in the CPCP and the magnetic field magnitude at geosynchronous orbit. We note that the grid resolution influences the magnitude of maximal electric current density at the magnetopause and possibly may change the total magnetopause current, but this problem requires more careful studies and it stays outside of the scope of the paper.