Wednesday, March 18, 2026

Solar Activity Report - March 9 - 15, 2026

Solar activity during the past week ranged from low to moderate. March 11 marked the quietest day, with the Xray flux remaining in the Bclass range and only minor Cclass flaring. Activity increased significantly by March 13, the most active day, producing an M1.2 flare - the strongest of the week - along with C8.9 and longduration C8.0 flares and several additional C-class events. A second Mclass flare, an M1.0, was produced on March 15 by active region 14392 located in the southeast quadrant of the solar disk. In total, 37 Cclass and 2 Mclass flares were produced. No Earthdirected CMEs were detected. 

Helioseismic maps of the far hemisphere reveal multiple active regions that rotated onto the far side after crossing the west limb.  These regions exhibited low to moderate activity while on the Earth‑facing side of the solar disk.  If they do not decay while on the far side, one of them is expected to rotate back into view on March 21.

At the time of preparing this report, an M2.7 flare was detected on March 16 from active region 14394, which also launched a CME directed toward Earth. The CME is forecast to arrive on March 19 and has the potential to generate auroral activity.

Tuesday, March 17, 2026

The Sun’s Far Side as Seen via Martian Observations and GONG Helioseismic Mapping

Solar activity is now in the declining phase of Solar Cycle25, leading to a marked reduction in both the number of active regions and the frequency of highenergy events. Frontside active regions continue to be monitored routinely from ground and spacebased observatories, but the far side lacks continuous direct coverage. NASA’s STEREO spacecraft and ESA’s Solar Orbiter provide intermittent farside observations that have been essential for validating helioseismic techniques used to infer active regions on the hidden hemisphere. However, because the visibility of the far side depends on each spacecraft’s orbital position, none of these assets provide fullhemisphere farside coverage at all times. For more information, please see an earlier post,

https://gongnisp.blogspot.com/2025/12/why-active-regions-appeared-displaced.html

Recent observations from NASA's Perseverance rover on Mars — currently positioned on the far side of the Sun relative to Earth —provide a valuable additional vantage point for viewing the Sun’s hidden hemisphere. In the image shown here, we compare the farside active regions inferred from GONG helioseismic mapping with those detected in the recently published Marsbased observations reported by Spaceweather.com.

Martian observation (right bottom panel of the accompanied image) indicates that four active regions seen on March6 in the northern hemisphere (left panel) remain on the solar disk, and these same regions are also captured in the GONG helioseismic maps (right top panel). One region highlighted in the GONG maps (marked with a red circle) does not appear in the Martian observations because of its position relative to Mars’s viewing geometry. The line marking this location shows clearly that the region lies outside Mars’s field of view. These differences arise primarily from the distinct image geometries and viewing angles of the two observing platforms.


Monday, March 16, 2026

M-class flare and prominence activity

A major M2.8 X-class flare occurred today (16 March 2026) in active region 14392. The flare started at about 12:00 UT and peaked at 12:15 UT. Flare and an activation and eruption of small filament from nearby active region was observed by several GONG stations. See video of event as observed in the hydrogen H-alpha spectral line by GONG/Cerro Tololo, Chile. Unrelated to this event, a large solar prominence in East-South limb showed some interesting flows. Flaring region is shown at 2 minute cadence time lapse, and the prominence is at 3 minute cadence. Videos cover about 5 hours for flare (11:34 UT- 16:36 UT) and 6 hours for prominence (11:34 UT- 17:35 UT). Full disk images for these events can be accessed via GONG web site at  https://gong.nso.edu/.

 

Sunday, March 15, 2026

GONG status for week of March 8-14 2026

 Here is a brief status of GING operations for week of March 8-14, 2026:

  • Most Instruments Operational: Instruments at Learmonth, Udaipur, El Teide, Cerro Tololo, and Big Bear were generally operational, though with varying sky conditions.
  • Instrument Down Time: GONG TC and TE instruments were down for testing. Access road to Mauna Loa Observatory is  now scheduled to be completed on March 25, 2026. 
  • Maintenance: A maintenance report for the El Teide site on March 11 noted that the anemometer was connected, but the emergency light inside the shelter had a bad battery.
  • Scheduled Scans: DRIFT Scans were performed at the Big Bear site on March 8 and March 14.
  • Community support: GONG observations were used to support the NASA's Parker Solar Probe’s 27th encounter, with perihelion that occurred on March 11 at 18:17 UT. Maps of predicted magnetic connectivity  based on GONG observations can be found at https://whpi.hao.ucar.edu/whpi_campaign-psp27p.php 
  • Wednesday, March 4, 2026

    GONG/TD status

    GONG/Teide (Canary Islands) has been down for several days (2-4 March 2026). They had very bad weather with temperatures bellow 0ยบ and very high humidity. Probably ice at formed on the turret. Local support team investigates.

    Sunday, February 22, 2026

    A day without sunspots

    Observations from GONG taken on 22 February 2026 show no sunspot (see upper-left image showing the Sun in a broadband wavelength range). Areas of brighter plages indicate the presence of magnetic field on the Sun, but the field is not strong enough to form sunspots or even pores. Image on upper-right is a map of magnetic fields (magnetogram) corresponding to the same time as the "white light" image. There dark/white colors correspond to magnetic field of negative/positive polarity.  The magnetic fields are organized in patterns of positive-negative polarity typical for decaying active regions. The conditions with no sunspots are usually observed during the minimum of 11-year solar cycle, although currently, the sun is in the middle of a declining phase of solar cycle 25 (see last plot taken from https://www.swpc.noaa.gov/products/solar-cycle-progression). 

     

    Saturday, February 21, 2026

    One day of a large solar prominence

     On 21 February 2026, a large solar prominence was observed on East-South limb. This video shows the change in filament appearance over 24 hour period. Video stars from GONG/Learmonth (Australia) at 00:00:42 UT. Then it switches to GONG/Cerro Tololo (Chile), and at the end, it goes
    back to GONG/Learmonth. The video ends on 22 February 2026 at 1:48:42 UT.

    Solar Activity Report - March 9 - 15, 2026

    Solar activity during the past week ranged from low to moderate. March 11 marked the quietest day, with the X ‑ ray flux remaining in the B ...