Solar Activity Report: March 16 - 22, 2026

The week began with moderate solar activity, which declined to low levels by mid‑week and remained low for the rest of the period, with only a slight gradual increase in X‑ray flux intensity that stayed within the B‑class range. Three low‑intensity M‑class flares occurred at the start of the week, one on each of the first three days. The most active day was March 18, when an M2.7 flare was produced, along with C2.7, C2.8, C2.9, and C3.6 flares. Other notable flares include an M2.8 and C5.9 on March 16, an M1.3 on March 17, and a C2.3 on March 19. All of these flares originated in the southern hemisphere, primarily from active region 14392. Two associated CMEs from the March 16 and March 18 M‑class flares arrived simultaneously on March 20.

Helioseismic mapping of the invisible hemisphere indicates that several active regions may rotate onto the Earth‑facing side within the next seven days. One of them is active region 14378, which crossed the west limb and moved to the far side about two weeks ago, has persisted and is expected to reappear at the east limb around March 24. 

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 311,  and  the  p-mode frequency data products for central GONG month 310 is completed and the data products are now available.

GONG refurbishment project update

NISP Data Center, scientists, and engineers have successfully completed vetting the last twelfth GONG EVT camera.

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‑class range and only minor C‑class 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 long‑duration C8.0 flares and several additional C-class events. A second M‑class 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 C‑class and 2 M‑class flares were produced. No Earth‑directed 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.

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

Solar activity is now in the declining phase of Solar Cycle 25, leading to a marked reduction in both the number of active regions and the frequency of high‑energy events. Front‑side active regions continue to be monitored routinely from ground‑ and space‑based observatories, but the far side lacks continuous direct coverage. NASA’s STEREO spacecraft and ESA’s Solar Orbiter provide intermittent far‑side 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 full‑hemisphere far‑side 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 far‑side active regions inferred from GONG helioseismic mapping with those detected in the recently published Mars‑based observations reported by Spaceweather.com.

Martian observation (right bottom panel of the accompanied image) indicates that four active regions seen on March 6 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.

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/.

 

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