GONG/LE - Weather Event

 The GONG program in Boulder has received word from the staff at the Learmonth Solar Observatory of an incoming tropical low to the region. "There is currently tropical low 21U heading southwards down the west coast of Western Australia and it is predicted to hit Learmonth late Sunday / early Monday as a category 1 cyclone. The USAF (who maintain the site infrastructure here) are not planning to shut down mains power." https://www.bom.gov.au/warning/tropical-cyclone-forecast-track-map/IDW60281

 

Dynamics of Subsurface Flows in Solar Active Regions during the 2024 Gannon Storm

 In May 2024, the Sun produced a series of intense flares and CMEs, primarily from NOAA Active Regions (ARs) 13663 and 13664, which were visible on the solar disk at that time. The image shows a full-disk magnetogram from the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory on May 6, 2024, highlighting both regions. While surface and coronal observations reveal much about these eruptions, active regions are rooted deep within the Sun. To explore the hidden dynamics beneath them, we use a local helioseismic technique that uses sound waves traveling through the solar interior to measure horizontal flows beneath these active regions.  

It is found that the flow divergence remained mostly negative throughout the observing period for all active regions, indicating that horizontal flows converge toward areas of strong magnetic field. It is also observed that the amplitudes of vorticity and kinetic helicity tended to increase before a series of flares occurred. After these flare episodes, the amplitudes decreased, only to rise again ahead of subsequent eruptions. This behavior was consistent across different depths below the surface, with deeper layers generally showing stronger signals. The Normalized Helicity Gradient Variance (NHGV), which captures how kinetic helicity varies with time and depth showed  that NHGV typically increased at least a day before flares. Notably, about 81% of the observed flares occurred either on the day NHGV reached a local  maximum or on the following day. Together, these results highlight the importance of subsurface dynamics in shaping the evolution and eruptive potential of solar active regions. 

This study was published in The Astrophysical Journal (Authors: B. Lekshmi, Sushanta Tripathy, Kiran Jain, and Alexei Pevtsov)  

https://iopscience.iop.org/article/10.3847/1538-4357/ade2e3 

X-ray flare in a growing active region

Active region 14366 crossed East solar limb at about 18:00 UT on 29 January, 2026. The region was growing rapidly, and it was a location of several moderate and strong flares. The strongest X1.0 class flare was observed early today at about 12:25-12:37 UT (peak at 12:33 UT). Attached video shows this flare as observed by H-alpha instrument at GONG station at El Teide, Canary Islands. The video starts at 09:07 UT, and it ends at 14:37 UT. Time cadence is 4 minutes (original GONG observations are taken at 1 minute cadence). The video demonstrates the complexity of flaring events with multiple brightenings as well as jet and filament eruptions (dark features) taking place before and after the peak of the X-ray flare.

GONG data processing update

Processing of the network-merged daily velocity and magnetogram images,  p-mode-coefficient time series, and ring-diagram analysis products for GONG month 310,  and  the  p-mode frequency data products for central GONG month 309 is completed and the data products are now available.

GONG Network Sites - Infrastructure Maintenance

 Air conditioner maintenance or replacement and shelter painting is planned for the near term for the Udaipur, CTIO, and Learmonth sites. There will be some limited site downtime associated with these activities.

 * Udaipur: The shelter painting is currently in work and is scheduled to be completed prior to February 10th.

* Udaipur: The purchase order is in place for the replacement of the two mini-split A/C units. The work will take place after the International Conference at the Udaipur Solar Observatory during February 10 to 13, 2026. This is the celebration event for the 50th anniversary of the Udaipur Solar Observatory.

* Udaipur: Quotes pending for replacement of the dehumidifier unit.

* CTIO: The CITO staff have a statement of work for the shelter painting that is out for bid.

* Learmonth: Air conditioner and  dehumidifier maintenance is scheduled for early February.

Blank magnetogram artefact

"Blank magnetogram" artifact reported in earlier post continue to be investigated. As a mitigation, for all affected GONG stations,  the workstation's Tsync board driver and the Data Acquisition System (DAS) software were updated. In addition, the team implemented a monitoring software code for early identification the problem. So far, only three stations (UD, BB and LE) that experienced the blank magnetogram artefact.

X-class flare observed by GONG/CT

Early today (18 January, 2026), GONG station at the Cerro Tololo Inter-American Observatory, Chile captured a major solar flare with its H-alpha instrument. The X-class flare was associated with the active regions 14345 and 14341. A pattern of bright two-ribbon flare suggests the presence of a coronal mass ejection (CME) associated with this event. After the eruption, CMEs undergo significant expansion (ballooning in size), and thus, while the eruption occurred east of the solar central meridian, there is a possibility that it could impact Earth when it reaches our planet's orbit.