SDO Observations of Solar Jets
We present an analysis of high cadence observations of solar jets observed in the Extreme Ultraviolet (EUV), at 304 Å, with the Atmospheric Imaging Assembly instrument aboard the Solar Dynamics Observatory (SDO). The jets in our sample lie very close to the solar limb to minimize projection effects. Two of the events show clear helical patterns during ejection. We also find that some of the jets are recurrent and that most of them cannot overcome solar gravity.
We investigate the temporal evolution of the jets by measuring the height of their leading edge as a function of time. By fitting the resulting height–time diagrams, we derive the magnitude of their initial ejection speed and plasma acceleration by assuming ballistic motion. Moreover, we calculate the upward acceleration of the jets based on the dynamical velocity of the plasma, without assuming a ballistic motion. In both models, the acceleration profiles suggest the influence of forces other than gravity. In particular, we find indications of an upwards driving force which weakens the decelerating effect of the solar gravitational field along the motion of the jet. This force is larger in the dynamical model, which indicates that the ballistic approximation does not properly determine the rising motion of the plasma jets.
KeywordsSolar jets Magnetohydrodynamics Magnetic field Active regions
- Gontikakis, C., Archontis, V., Tsinganos, K.: 2009, Solar Phys. 506, L45. Google Scholar
- Kamio, S., Hara, H., Watanabe, T., Matsuzaki, K., Shibata, K., Culhane, L., Warren, H.P.: 2007, Publ. Astron. Soc. Japan 59, S757. Google Scholar
- Lemen, J.R., Title, A.M., Akin, D.J., Boerner, P.F., Chou, C., Drake, J.F., Duncan, D.W., Edwards, C.G., Friedlaender, F.M., Heyman, G.F., Hurlburt, N.E., Katz, N.L., Kushner, G.D., Levay, M., Lindgren, R.W., Mathur, D.P., McFeaters, E.L., Mitchell, S., Rehse, R.A., Schrijver, C.J., Springer, L.A., Stern, R.A., Tarbell, T.D., Wuelser, J.-P., Wolfson, C.J., Yanari, C., Bookbinder, J.A., Cheimets, P.N., Caldwell, D., Deluca, E.E., Gates, R., Golub, L., Park, S., Podgorski, W.A., Bush, R.I., Scherrer, P.H., Gummin, M.A., Smith, P., Auker, G., Jerram, P., Pool, P., Soufli, R., Windt, D.L., Beardsley, S., Clapp, M., Lang, J., Waltham, N.: 2012, Solar Phys. 275, 17. ADSCrossRefGoogle Scholar
- Shibata, K., Nakamura, T., Matsumoto, T., Otsuji, K., Okamoto, T.J., Nishizuka, N., Kawate, T., Watanabe, H., Nagata, S., UeNo, S., Kitai, R., Nozawa, S., Tsuneta, S., Suematsu, Y., Ichimoto, K., Shimizu, T., Katsukawa, Y., Tarbell, T.D., Berger, T.E., Lites, B.W., Shine, R.A., Title, A.M.: 2007, Science 318, 1591. ADSCrossRefGoogle Scholar