Solar Activity Report: March 30 - April 5, 2026

 Solar activity fluctuated sharply over the past week. The period opened at high levels on March 30 with a long‑duration X1.4 flare from active region 14405, located in the southeastern quadrant of the visible disk. Activity then dropped markedly on March 31, with the strongest event reaching only C1.5 before declining into the B‑class range. Conditions rose again on April 1 as multiple high‑intensity C‑class flares were recorded, the largest being a C8.1 event. From April 2 through April 4, activity remained at moderate to high levels, driven by several M‑class and numerous strong C‑class flares. The largest daily events were M3.5, M1.3, and M7.5 on April 2, 3, and 4, respectively. Activity decreased once more on April 5, with a C3.8 flare as the day’s peak.

In summary, April 4 stood out as the most active day of the week. Active region 14409 dominated the activity, producing six M‑class flares and roughly 50 C‑class flares. Several CMEs were detected by coronagraphs throughout the week, but none were assessed to have significant Earth‑directed impacts.

Helioseismic maps of the far side show several active regions currently present. One of them—an active region from the previous rotation—appears to have a high likelihood of returning to the visible hemisphere around April 11.

Major M1.0 X-class flare on April 4, 2026

 On April 4, 2026, a major X-class solar flare of M1.0 magnitude was observed at about 22:54 UT in active region NOAA 14409. The flare was recorded by GONG/Big Bear station using its Hydrogen H-alpha instrument. GONG/BB restarted its observations on the day of flare after been down for a preventive maintenance. Image shows the location of flaring region before (22:39 UT) and during the flare (23:02 UT, marked by thick black arrow). The active region continues exhibiting a complex magnetic configuration and new flux emergence, and thus, may produce additional flares. The observations can be access via GONG website.

 

GONG low duty cycle (updated on 4/4/2026)

GONG network is operating at a very low duty cycle (see plot attached) due to three adjacent stations  down: GONG/Mauna Loa - in aftermath of volcanic eruption, GONG/Big Bear - preventive maintenance trip, and GONG/Learmonth - damages in aftermath of the tropical cyclone (TC) Narelle.

The LE GONG station was shut down on March 25th in anticipation of the arrival of Tropical Cyclone Narelle. TC Narelle caused significant damage to Exmouth and Learmonth, but there is no damage to GONG/Learmonth station itself, except for one air-conditioning units, and some external access power panels. After the electrician inspection, the power to GONG was restored, and the instrument may have resumed observations. However, there is no internet access and thus, data are stored on the site. 

NISP engineering team are performing preventive maintenance work at GONG/Big Bear. It is expected that GONG/BB will be back to operations on 4/4/2026. UPDATED on 4/4/2026: The preventive maintenance was completed. GONG/Big Bear is back to full operations.

Primitive access road to Mauna Loa is completed, but access is still limited. NISP team plans visiting the site for the evaluation of restart activities after the commercial power to the site is restored.

GONG/LE Status

 The LE GONG station was shut down on March 25th in anticipation of the arrival of Tropical Cyclone Narelle. TC Narelle made landfall near Exmouth at approximately 8am on March 27th at a Category 4 level with wind speeds between 160–199 km/h. An electrician was able to visit the site, and power was restored to the shelter on April 2nd. We are awaiting word as to when the internet connection to the LSO will be restored.

 One of the first reports from the LSO staff reads:

"Unfortunately, the damage to Exmouth and Learmonth is significant. The road was closed for days due to flooding and the airport across the road is closed for the foreseeable future due to extensive damage to the terminal.

We were able to access the site for the first time yesterday (March 31st) and inspected the GONG shelter. The shelter and turret appear to be unscathed (no obvious wind damage or impacts) but one of the air-conditioner compressor units has been damaged.

The inside of the shelter was dry (hooray) so we attempted to repower, however the main circuit breaker tripped on both attempts. The metal box surrounding the main circuit board outside was blown open and bent at the hinge, and we suspect water may have gotten in behind it. It's also possible there is water in the light fixtures that may be tripping the circuit breakers.

We are also experiencing a site-wide internet outage, so no data flow is possible currently anyway. We are investigating with the network provider to find out what kind of infrastructure damage has occurred and ETA for return to service. We will keep you posted on this front too."

 

Does the Solar Tachocline Change with Solar Cycle

 A thin transition layer where the Sun’s rotation changes abruptly — the outer convection zone rotates differentially, while the inner radiative zone rotates almost like a solid body- is termed as the tachocline similar to the thermocline in oceanic dynamics.  This sharp shear is believed to generate the Sun’s strongest toroidal magnetic fields, which later rise to the surface as sunspots. The tachocline’s  sub-adiabatic stratification allows strong magnetic fields to be stored without immediately rising due to buoyancy. If the solar dynamo exists in the tachocline and generates the magnetic field of the Sun, one would expect solar-cycle related changes in the properties of the tachocline. 

A recent study using three decades of GONG observations reports a secular shift in the tachocline’s position at low latitudes. The analysis also indicates that the tachocline  has been gradually moving closer to the base of the convection zone, indicating that it may be related to the complexity of the solar magnetic field.  

This work is published in Astrophysical journal, 1000, 272 (1000) 2026 April 1. 

Latitude-dependent Time Variations of the Solar Tachocline - IOPscience

Artemis 2 launch and space weather

Artemis II is scheduled to launch tomorrow (April 1, 2026) on a 10-day mission around the Moon. Traveling outside the Earth magnetosphere may pose additional risks from the space weather events (for review of early studies see Chen et al 2024). NOAA Space Weather Prediction Center will provide forecast of space weather conditions for the duration of mission (see article in Space.com), and the NSF's GONG observations will contribute to the modeling. In addition, recent GONG farside images suggest a relatively low level of sunspot activity on a farside of the Sun for the incoming two weeks. 

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.