Solar Activity Report: March 23 -29, 2026

Solar activity during the reporting period ranged from low to moderate levels. The week began with low solar activity and a C3.2 flare was the largest event on March 23 that originated from active region 14392 near the southeast limb. The X‑ray flux generally remained at B‑level until a C7.3 flare was produced on March 24 by an active region rotating onto the Earth‑facing side from behind the northeast limb. This region was later designated NOAA 14403. Following this event, the X‑ray flux stayed within the C‑level range, with several C‑class flares and two M‑class flares. The largest event on March 25 was a C3.7 flare. Activity increased to moderate levels on March 26 with an M3.9 flare from active region 14403 and multiple additional C‑class flares.

On March 27, activity declined again to low levels, with only C‑class flares observed; the largest was a C5.4 event. Activity increased once more on March 28 with a long‑duration M1.3 flare from active region 14405. The week concluded with low activity on March 29, when the largest event was a C2.1 flare. Overall, active region 14405 was the most productive during this period, generating nine C‑class flares and one M‑class flare. Several CMEs were associated with these events, but none had Earth‑directed components.

Status of GONG network: March 27, 2026

 Status of GONG network as of Friday, March 27:

• The Learmonth instrument is down due to passage of a tropical cyclone (see map below showing path of tropical cyclone Narelle 34U, © Bureau of Meteorology) 
• The Udaipur instrument is unreachable (local team was requested to investigate).
• The El Teide instrument is operational, and the sky is clear.
• The Cerro Tololo instrument is operational, and the sky is clear.
• The Big Bear instrument is down for scheduled maintenance. NISP engineering team is on site performing preventive maintenance.
• Road to Mauna Loa Observatory is officially completed. However, it remains closed for general public and non-emergency observatory access.

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.