Guest Stephane Mabille Posted December 17, 2015 Share Posted December 17, 2015 NASA GODDARD SIMULATION OF DYNAMICS CME ON WAY CONNECTED SUN - EARTH. Two solar flare yesterday are being hit planet Earth in the next three days with a dynamic ensemble for a possible clash of front bow. The simulation provides a geomagnetic activity can be sustained density wave and bow shock at the conclusion of behavioral analyzes of the pair of CME issued yesterday the first of which was attributed to a class C6.6 10 h 03, the second was a coronal disturbance southern quadrant of the sun. The two LO (s) were analyzed as asymmetric Halso and should have components directed towards the Earth exclusively as the halo is the equatorial face the sun. CME activity may have aggressive behavior (sudden drop Bz) in connection with two plasma density waves and speed of rotation beyond 670 -720 km / s - significant potential of the interplanetary magnetic field. The geomagnetic activity could be elevated on December 19 to 20, 2015. September proton increase may take place before passage of the CME in the environment geomagnetic <S 1-10 P - 3 cm Link to comment Share on other sites More sharing options...
Waldo Hazeleger Posted December 17, 2015 Share Posted December 17, 2015 In this article on the frontpage, you talk about speed of the CME's that were launched yesterday. The first one from 16/09:24, has a speed of 550 km/s, the second one from 16/14:24 has a speed of 490 km/s. If i'm right, you can calculate the arrival time at earth according to formula: Time (hrs) = 150.000.000 / 3600 / speed, so 75,75 hrs for the first, 85,03 hrs for the second CME. This makes the arrival time for the first at 19/13:09 and for the second 20/03:29 My question is were the CME speeds are coming from. On the cactus page from sidc.be the CME's are listed as: # CME | t0 | dt0| pa | da | v | dv | minv| maxv| halo? 0013|2015/12/16 14:24| 04 | 153| 116| 0284| 0010| 0257| 0303| II 0011|2015/12/16 09:24| 02 | 081| 172| 0391| 0145| 0202| 0657| II I can't find the given speeds in this list. Do you know were they are based on? Link to comment Share on other sites More sharing options...
Marcel de Bont Posted December 17, 2015 Share Posted December 17, 2015 I saw the CACtus speeds last night but I did not trust them so we waited for the SIDC news bulletin at http://www.sidc.oma.be/ They know their stuff and are a reliable source. Europe's SWPC. Link to comment Share on other sites More sharing options...
Waldo Hazeleger Posted December 17, 2015 Share Posted December 17, 2015 The cactus list is also from sidc.oma.be, but it is the computer generated using the cactus software program. I guess that you find that list not reliable enough, or at least not for the two CME's we're having now. By the way: The swpc has upgraded the G1 watch to G2 level for the 19th. They seems to think as well that the speed looks higher and have more impact. I remember some time ago that we also had two cme's close together, and tat the combination of them had much higher impact than they would have separately. Link to comment Share on other sites More sharing options...
Marcel de Bont Posted December 17, 2015 Share Posted December 17, 2015 We do use the CACtus list but the speed CACtus gave just didn't feel correct just by watching the images. I am not sure where the SIDC got the speeds from that they used in today's report, maybe they measured it manually somehow. Yeah it does look like the SWPC used an even faster speed for these CMEs. Will be interesting to see what is going to happen. It's hard enough with just 1 CME, let alone 2. G2 is possible but we really need the IMF to cooperate to get G2 with these low CME speeds. Link to comment Share on other sites More sharing options...
Jesterface23 Posted December 17, 2015 Share Posted December 17, 2015 Figured out some math that should come close on the arrival time using SDO AIA 131 and SOHO LASCO C3 images. That comes up with December 19th at 5:56z +- 3+ hours on the first CME and December 19th at 14:07z +- 3 hours on the 2nd CME. I noticed they did something to the LASCO C3 camera a few days ago, so not sure if the math would need a multiplier. Link to comment Share on other sites More sharing options...
Vancanneyt Sander Posted December 17, 2015 Share Posted December 17, 2015 4 uren geleden, Waldo Hazeleger zei: In this article on the frontpage, you talk about speed of the CME's that were launched yesterday. The first one from 16/09:24, has a speed of 550 km/s, the second one from 16/14:24 has a speed of 490 km/s. If i'm right, you can calculate the arrival time at earth according to formula: Time (hrs) = 150.000.000 / 3600 / speed, so 75,75 hrs for the first, 85,03 hrs for the second CME. This makes the arrival time for the first at 19/13:09 and for the second 20/03:29 My question is were the CME speeds are coming from. On the cactus page from sidc.be the CME's are listed as: # CME | t0 | dt0| pa | da | v | dv | minv| maxv| halo? 0013|2015/12/16 14:24| 04 | 153| 116| 0284| 0010| 0257| 0303| II 0011|2015/12/16 09:24| 02 | 081| 172| 0391| 0145| 0202| 0657| II I can't find the given speeds in this list. Do you know were they are based on? Minv and maxv are the minimal and maximal velocity, v as median velocity of all data points as measured by the cactus program calculation of the speed is measured frame by frame difference of the moving cloud. With complex CME's it's difficult to determine the correct speed with parts of a halo CME that can be faster than the other. We really need 3D modeling of CME's to see it from multiple views to really accurately detect the speed and evolution of the expanding charged cloud. Calculating arrival speed is way more difficult. CME's can slow down as they travel through the interplanetary space due to other CME's, coronal holes, Parker spiral, ... . All models of CME arrival times are still so inaccurate. Even ENLIL is more wrong then right in arrival times. It would be great if it was that easy to calculate but today we still have a big + and - on the arrival times and even then we see CME's that are way too late or surprisingly early Link to comment Share on other sites More sharing options...
Waldo Hazeleger Posted December 17, 2015 Share Posted December 17, 2015 Ok, I understand, calculating arrival times isn't just T=150M / 3600 / speed. It is way more complex. When I now look at the two enlil models, noaa and nasa, they have a 12 hour difference in arrival time, so we have to wait and see. Hopefully it will be a bit late, so that we can go outside the night of the 19th. Link to comment Share on other sites More sharing options...
Guest Stephane Mabille Posted December 19, 2015 Share Posted December 19, 2015 Impact moderate 15 h 30 (UTC) Link to comment Share on other sites More sharing options...
Waldo Hazeleger Posted December 19, 2015 Share Posted December 19, 2015 ACE Epam still rising, so I think impact still going on. Link to comment Share on other sites More sharing options...
Guest Stephane Mabille Posted December 19, 2015 Share Posted December 19, 2015 For the moment Link to comment Share on other sites More sharing options...
Guest Stephane Mabille Posted December 20, 2015 Share Posted December 20, 2015 Geomagnetic Storm G 2 activ courant geomagnetic tension low Queensland in Australia analyse BOM SPW Link to comment Share on other sites More sharing options...
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