Lịch sử của bầu khí quyển Trái Đất trong thời gian một tỷ năm trước đây vẫn chưa được hiểu rõ lắm. Hiện nay bầu khí quyển Trái Đất vẫn là một đề tài nghiên cứu của các nhà khoa học. | 206 . Bellot Rubio measurements at very high spatial resolution. With it should be possible to determine the flow field across penumbral filaments resolving internal fluctuations smaller than the width of the filaments themselves. Hopefully this kind of observations will be provided soon by instruments like IMaX aboard SUNRISE or CRISP at the Swedish Solar Telescope. 5 Conclusions The Evershed flow exhibits conspicuous fine structure at high angular resolution. It occurs preferentially in the dark cores of penumbral filaments at least in the inner penumbra. The flow is magnetized and often supersonic as demonstrated by the observation of Stokes V profiles shifted by up to 9 km s-1. At each radial distance the flow is associated with the more inclined fields of the penumbra in the inner penumbra this happens in the bright filaments while in the outer penumbra the dark filaments have the largest inclinations. The flow is also associated with weaker fields except perhaps near the edge of the spot . High-resolution magnetograms by Hinode show the sources and sinks of the Evershed flow with unprecedented clarity confirming earlier results from Stokes inversions at lower resolution on average the flow points upward in the inner penumbra then becomes horizontal in the middle penumbra and finally dives down below the solar surface in the outer penumbra. The Hinode observations reveal tiny patches of upflows concentrated preferentially in the inner penumbra and patches of downflows in the mid and outer penumbra presumably they correspond to the ends of individual flow channels. Recent numerical calculations by Ruiz Cobo and Bellot Rubio 2008 have demonstrated that Evershed flows with these properties are capable of heating the penumbra very efficiently while reproducing many other observational features such as the existence of dark-cored penumbral filaments. This result strongly suggests that the radial Evershed flow is indeed responsible for the brightness of the .
