The solar atmosphere exhibits diverse jetting phenomena, appearing as collimated plasma
beams that span a broad range of spatial and temperature scales—from large-scale X-ray and
Extreme Ultraviolet jets in the corona to small-scale jets in the lower solar atmosphere. These
jets occur across all types of solar regions, including active regions, coronal holes, and the quiet
Sun. Our understanding of these jets remained limited until the advent of high-resolution
observations, which now enable us to probe tiny jets with widths of less than 1 Mm and lifetimes
of only a few tens of seconds. These observations have opened a new window into studying
magnetic reconnection and energy release at the smallest observable scales in the solar
atmosphere.
In this talk, I will present a series of recent studies that investigate the origin of tiny jets using a
combination of space-based observations from the High Resolution Imager on board Solar
Orbiter, the Interface Region Imaging Spectrograph (IRIS), and the Atmospheric Imaging
Assembly and Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory,
together with ground-based observations from the Goode Solar Telescope (GST) at the Big
Bear Solar Observatory. I will begin with picoflare jets (with kinetic energy of the order of 1021
ergs) observed by Solar Orbiter, where tiny off-limb coronal jets show coupled bright and dark
components produced by low-altitude magnetic reconnection during flux emergence. Then I will
discuss reconnection nanojets (with kinetic energy of the order of 1024 ergs) observed in both
eruptive and confined flare regions, which reveal that the surrounding magnetic field
configuration plays a significant role in controlling their speeds and energies. Next, in the
chromosphere, I will show recurrent fan-shaped jets observed by GST that are driven by
magnetic flux cancellation and reconnection at a null point, consistent with the mini-filament
eruption model. Finally, I will present jet eruptions associated with small-scale loop-like
structures observed with IRIS and GST that display signatures of plasmoid-mediated
reconnection. Together, these results suggest a common magnetic reconnection process
operating across multiple layers of the solar atmosphere, linking the formation of tiny jets to
larger-scale solar activity and providing insight into coronal heating. These studies demonstrate
the ability of high-resolution observations to resolve the dynamics of small-scale jets and place
new constraints on their origin.