Solar filaments, also called solar prominences when appearing above the solar limb, are cold, dense materials suspended in the hot tenuous solar corona, consisting of numerous long, fibril-like threads. These threads are the key to disclosing the physics of solar filaments. Similar structures also exist in galaxy clusters. Besides their mysterious formation, filament threads are observed to move with alternating directions, which are called counterstreaming flows. However, the origin of these flows has not been clarified yet. Here we report that turbulent heating at the solar surface is the key, which randomly evaporates materials from the solar surface to the corona, naturally reproducing the formation and counterstreamings of the sparse threads in the solar corona. We further suggest that while the cold Hα counterstreamings are mainly due to longitudinal oscillations of the filament threads, there are million-kelvin counterstreamings in the corona between threads, which are alternating unidirectional flows.

日光丝，当出现在日光柱上方时，也称为日光突起，是冷的致密材料，悬浮在热的，脆弱的日冕中，由许多长的，类似纤维的长丝组成。这些螺纹是揭示太阳能丝的物理原理的关键。类似的结构也存在于星系团中。除了其神秘的形态外，还观察到细丝线以交替的方向移动，这称为逆流。但是，这些流量的来源尚未弄清。在这里，我们报告太阳表面的湍流加热是关键，它使材料从太阳表面随机蒸发到日冕，从而自然地再现了日冕中稀疏线的形成和逆流。