The Coronal Solar magnetism Observatory (COSMO)

Evolving magnetic fields in the solar atmosphere can create explosive energetic solar storms that impact the earth. Known as space weather, these events can damage orbiting satellites, disrupt communications and GPS networks, disable power grids, and pose health risks to astronauts and airline passengers.

Large Coronagraph Current Design Rendering image
(left) Cutaway rendering showing the inside of the dome housing the Large Coronagraph.
(right) Rendering of the exterior of the Large Coronagraph facility showing the control building and fifth/eighth’s dome.

Motivated by society's need to protect human welfare and critical infrastructures, NCAR scientists at the High Altitude Observatory, along with colleagues at the University of Hawaii, the University of Michigan, George Mason University and the Harvard-Smithsonian Center for Astrophysics, plan to build the Coronal Solar Magnetism Observatory (COSMO). The goals of this activity are to understand the physical processes that cause space weather and to develop the ability to predict the occurrence and severity of solar storms. COSMO is a facility that will take daily measurements of the entire solar atmosphere, focusing on the magnetic fields that drive solar eruptive events. The primary instrument, the Large Coronagraph, will consist of a 1.5-m coronagraph that will measure the strength and orientation of magnetism in the outer solar atmosphere, the corona, as well as the density, temperature and motion of coronal plasma. Supporting instruments are a white-light coronagraph, the K-coronagraph that will monitor the evolution of the density and dynamics of coronal electrons, and an instrument called ChroMag that will observe the magnetism and plasma properties of the lower and middle solar atmosphere, the photosphere and chromosphere. This new facility will replace the current NCAR Mauna Loa Solar Observatory (MLSO) which has been collecting synoptic coronal data for over 50 years in support of the solar and heliospheric community.

We continue to make progress towards the completion of COSMO. The K-coronagraph was deployed to MLSO in September of 2013 and has been operational since. Data from the K-Cor can be obtained at: The Large Coronagraph is in the planning and engineering development stage. A significant milestone was achieved in November 2015 when we completed a Preliminary Design Review for the COSMO Large Coronagraph where an external committee of experts from the community reviewed the maturity of the design and verified the feasibility of constructing the instrument. The PDR is documented extensively with engineering studies, preliminary designs, and vendor quotes for all major components (see: And recently, funding has been obtained that will allow the ChroMag instrument to be completed in the next 2 years and put into operation at Mauna Loa.

Future efforts center on obtaining the remaining funds required to complete the Large Coronagraph. A rendering of the current design for the LC is shown in the figure.