Exploring if a coronal dimming event can produce coronal hole-like properties

Coronal dimmings, or transient coronal holes, are manifested as a sudden reduction in extreme ultraviolet (EUV) and X-ray emission, often following solar eruptions. We investigate whether a dimming event can produce coronal hole-like plasma characteristics in the initially quiet Sun. On 17 and 18 March 2022, Solar Orbiter, Hinode, IRIS, and SDO observed a coronal dimming event that occurred after a quiescent filament eruption. We analysed imaging and spectroscopic data to compare the chromospheric and coronal response prior to and during the coronal dimming. The SDO/AIA 193;Å emission intensity in the dimming region was reduced to the same level as the neighbouring coronal hole within 11,hours. The Doppler velocity measured with Fe XII (corona) decreased from -0.34^ +0.37 _ -0.27 , towards a predominant upflow of -3.2^ -1 +0.4 _ -0.6 , . The first ionisation potential (FIP) bias was reduced towards photospheric values. We found an increase in the number of automatically detected EUV brightenings near the dimming boundary in SDO/AIA 193 Å,, which could be a sign of magnetic reconnection. In the cooler SDO/AIA 171 Å or Solar Orbiter HRI_ k_3 (chromosphere) Doppler velocities were unchanged, except for a small reduction in the dimming upflows in areas with weak magnetic fields ($<20$ G). -1 174 Å; channel, we did not observe such an increase. Coronal bright points (CBPs) appeared relatively unaffected by the formation of the dimming. The Mg II We find that the dimming only shows partial coronal hole-like properties; specifically, in the coronal emission lines and at temperatures of $>1$ MK. We suggest that this is due to the dimming resulting from plasma depletion only at higher altitudes. Since the CBPs were not significantly impacted by the dimming, we used their magnetic loop heights (∼ 10 Mm) as the lower limit to the dimming height. Our findings provide new insights into the atmospheric structure of coronal dimmings.