On the other hand, an enhanced ring most recent during magnetic storms can get push the newest subsolar magnetopause external (elizabeth

Having fun with seemingly brief (20 minute) time times within active pressure measures, i implicitly think that the alterations regarding the magnetopause standing mostly come from the changes about solar power breeze pressure and you will variations of your own dayside job-lined up Part step 1 currents. As the magnetotail current could have a slightly larger effect time, in standard it simply intensifies the end result of your Region 1 current. grams., specific estimations were made within the Samso ); not, (1) the noncoupled MHD design which efficiency have been demonstrated significantly more than really does maybe not reproduce brand new ring newest and (2) the period of ring newest intensification is commonly much more as compared to step three–4 hr utilized in this type of simulations. We work of your own coupled designs lower than that is qualitatively similar to the consequence of the newest noncoupled model, and this doesn’t change our very own conclusions.

In the long run, we should contrast multiple operates to verify our results are model-separate. Table step 1 accumulates the advantage rules indicator Letter for the (1) computed from half dozen items off three internationally MHD designs. The foremost is the noncoupled SWMF design whoever overall performance have been shown significantly more than. In addition to the very first operates (Version step one), przeglÄ…d fruzo i artificial around three almost every other products of your the same noncoupled model, several with a high ionospheric conductivity plus one with an excellent dipole tip. The new level-integrated Pedersen conductivity is assumed getting equal to 5 S throughout the brands, but versions dos and 3 wherein the newest incorporated conductivity was ten and you may one hundred S respectively. From inside the version 4, i artificial this new magnetosphere which have a dipole tip 31° . Changes in Letter ranging from Items step one and 2 and you can Versions step 1 and you will cuatro is quick, and you may between Types step one and 3 try reasonable, however, only for the brand new southward IMF. Keep in mind that the new ionospheric conductivity one hundred S is quite high and you may are hardly noticed in truth. I show they in order to train the brand new role from conductivity as the the 2 times upsurge in conductivity within the Type dos alter Letter only for this new acceleration improve that have southward IMF.

An increase in new magnetotail current as well escalation in the fresh new Region step one currents weakens new magnetospheric magnetic career and you will motions the latest dayside magnetopause earthward

Variation 5 represents runs of SWMF model coupled with total interior-magnetosphere ionosphere, and you may Type six ‘s the LFM-Merge design. Per type, i make four runs toward northward/southward IMF and also for the occurrence and speed increases as the explained more than (twenty four operates altogether). Bear in mind that Letter=6 regarding the most useful theoretic case whether your magnetopause condition fits the pressure balance involving the solar cinch dynamic pressure together with World’s dipole industry and you can Letter=six.six regarding empirical Shue et al. ( 1998 ) design. Actually, every acquired N is actually anywhere between both of these thinking or a little quicker. Five off six brands expect Letter huge otherwise equivalent to 7 on runs to your density increase to have southward IMF. Even in the event Version 5 predicts N smaller compared to 7, N are systematically large in such a case for every single design.

At the same time, Tsyganenko and Sibeck ( 1994 ) detailed your cross-end most recent and in a less knowledge the ring newest along with the location 1 currents determine the fresh new magnetic field for the magnetospheric section 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 R_E 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.