Mauna Loa Solar Observatory Reopens after 3+ years

The NCAR Mauna Loa Solar Observatory (MLSO) has reopened 3 years, 4 months, and 3 days after the volcanic eruption of November 28, 2022 damaged the access road to the observatory. MLSO currently has two main solar telescopes: the K-Coronagraph (K-Cor) and the Upgraded Coronal Multichannel Polarimeter (UCoMP) with a third instrument, the Chromospheric Magnetograph (ChroMag), due to be installed later this year. The K-Cor instrument is online now and captures polarized white-light observations of the solar corona from 1.05 to 3 solar radii, allowing prompt detection of coronal mass ejections (CMEs) approximately 30-60 minutes before they are visible to space-based coronagraphs such as NOAA’s CCOR or the ESA/NASA SOHO/LASCO C2 instrument. With its high image cadence of 15 seconds and 2.5 minute data latency from observatory to L2 processed images in Boulder, Colorado, K-Cor can alert space weather forecasters to high-speed CMEs that are the progenitors of dangerous radiation storms. K-Cor is supporting the upcoming NASA Artemis II mission as well as future NASA deep space human exploration missions with prompt CME alerts and measurements. UCoMP, which will come back online in late April, provides multi-wavelength polarimetric images of the corona from 1.03 to 2.1 solar radii, enabling measurements of thermal line width, electron density, and plane-of-sky magnetic field and doppler velocity. UCoMP measurements are key to understanding coronal magnetic plasma dynamics and serve as the pathfinder observations for the upcoming COSMO 1.5 meter solar coronagraph. For more details and data access, please see https://www2.hao.ucar.edu/mlso.