Upcoming Events
Colloquium: Stellar Evidence of a Collapsing Solar Dynamo - May 6, 2026
Colloquium: Probing the solar corona with the Solar Orbiter/Metis coronagraph: from instrumentation to CME diagnostics - May 15, 2026
Latest News
HAO Interim Director, Mike Wiltberger
We welcome Dr. Mike Wiltberger as HAO Interim Director. His 22 years at HAO, combined with his scientific expertise and inter‑agency experience at NSF, make him exceptionally well prepared for this leadership role.
NASA selects NSF NCAR Heliophysics Mission for Continued Development
In December 2025, NASA selected the Chromospheric Magnetism Explorer (CMEx) for an extended period of concept development. The $150 million mission would fill a critical solar observational gap, generating information on conditions that lead to solar eruptions, advancing our knowledge of the solar magnetic field, and improving space weather modeling capabilities. It would also be the first Explorer-sized spacecraft mission ever led by NSF NCAR.
July book release: "Physical Foundations of Spectroscopy" by Philip Judge
"Physical foundations of spectroscopy," by Philip Judge, highlights how spectroscopy is firmly anchored in physical foundations, countering modern trends leading to over-specialization. Published by Oxford University Press as a text in their master series in particle physics, astrophysics and cosmology.
Latest Research Highlights
Optimal Polarization Modulation and Calibration Schemes
Authors R. Casini, D. Harrington, and A. de Wijn review the algebraic definition of the efficiency of a polarization modulation scheme, which is commonly adopted for solar and stellar spectro-polarimetry applications, and generalize it to allow distinct states of the modulation cycle to have arbitrary throughput and different photon-noise statistics for each state.
The Ionospheric Lunar Tidal Response to the 2020-2021 Sudden Stratospheric Warming Observed by COSMIC-2, ICON and Modeled by SD-WACCMX, TIE-GCM
D. Aggarwal, S. Kumar, B. C. Martinez, N. M. Pedatella, X. Lu, and J. Oberheide examine how a major SSW in 2020-2021 affected global atmospheric waves called lunar tides using electron density data from the COSMIC-2 satellite (GIS), vertical plasma drifts from NASA’s ICON mission, and simulations from the SD-WACCM-X and TIE-GCM model.
Sudden ionospheric disturbances generated by solar flares—not so sudden?
B. Maletckii, E. Astafyeva, N. M. Pedatella, and L. Qian use high-rate 1Hz data of ionospheric total electron content (TEC) and we analyze ionospheric effects of 13 solar flares that occurred between 2003 and 2023. For the first time, we demonstrate that the SID first appears at the subsolar point (i.e., the point where the Sun is directly overhead), and further expands to the twilight regions at a very high speed.