Infrared Observations of Pore and Surrounding Regions with CO 4.66 μm Lines with CYRA

Observations of carbon monoxide (CO) in the solar atmosphere indicate the presence of lower-temperature gas. Utilizing the strong CO lines at around 4.66μm, we can detect the properties and dynamic evolution of the thermal structures of the lower solar atmosphere. In past decades, the properties and dynamics of sunspots and quiet-sun granules have been investigated through CO lines, whether by observations or numerical simulations. This work observes pores, quiet-sun, and network magnetic field regions with CO 4.66μm lines by Big Bear Solar Observatory /Cryogenic Infrared Spectrograph (CYRA). We find the CO spectral profiles for different pores share a similar line shape though the radiation intensities are different, indicating different temperatures in other pores. We further analyze the relationship between the CO 3-2 R14 line intensity and magnetic field strength. The quiet-Sun regions with weak magnetic field strength show significant changes in the CO 3-2 R14 line intensity, indicating the temperature of the quiet-Sun atmosphere is highly dynamic, as previous studies point out. As the magnetic field gets stronger, the line intensity changes to be enhanced or diminished, which should be caused by different heating effects in different-size magnetic flux tubes. Several “cold bubbles” can be seen in CO 3-2 R14 line intensity image. As previous studies found, some of them are located in the quiet-sun region without a magnetic field. However, we find another part of them are near or surrounded by magnetic fields. Remarkably, some are just located at the edge of the magnetic network. A similar relationship between “cold bubbles” and network magnetic field is also reproduced by our radiation-magnetohydrodynamic (MHD) simulation data with Bifrost code. Our observation and simulation illustrate that the magnetic field plays a vital role in the generation and dynamic evolution of CO cold bubbles.