BENGALURU: Isro Tuesday said it closely monitored and captured the signatures of the powerful solar storm triggered by the highly active sunspot region — AR13664 — that impacted Earth in early May 2024, unleashing a series of intense X-class flares and coronal mass ejections (CMEs) directed towards our planet.
The resulting geomagnetic storm was the strongest since 2003, causing disruptions to communication and GPS systems, especially at high latitudes.“…This storm was comparable to the historic Carrington Event of 1859, with trans-polar flights diverted and effects concentrated over high latitudes in the Pacific and American sectors,” Isro said.
Spacecraft OK
“No major upsets or anomalies were reported in Isro’s 30 GEO spacecrafts or Earth Observation Satellites. However, the increased atmospheric density caused by the solar event led to increased orbit decay, with some satellites experiencing 5-6 times higher decay compared to nominal values on May 11, 2024,” Isro said.
It added that its navigation centre has not noticed any significant degradation in the NaVIC service metrics till now, indicating no or negligible impact from the geomagnetic storm.
Ground observations
Observations from ground during the early morning hours of May 11 in India revealed a decrease of over 50% in Total Electron Content (TEC) at NARL, Gadanki, indicating an underdeveloped ionosphere.
“Daytime TEC was high by about 10% with large variations, while evening TEC was nearly 30% more, with no L-band scintillation or bubbles observed. At Thumba, the TEC values sharply enhanced, leading to over 100% increase compared to the control day, reaching around 80 TECu by 9am, which is significantly higher than typical values of 10-20 TECu at that time,” Isro said.
Aditya-L1 observations
Isro mobilised all its observation platforms and systems to record the signatures of this event. Both Aditya-L1 and Chandrayaan-2 have made observations and signatures have been analysed.
“Aditya-L1 spacecraft, situated at the L1 point, recorded high-speed solar wind, high-temperature plasma, and energetic ion flux associated with the CMEs using its ASPEX payload. The X-ray instruments on Aditya-L1 also captured the powerful X-class flares, while the magnetometer detected perturbations in the interplanetary magnetic field,” Isro said.
The X-ray payloads on-board Aditya-L1 (SoLEXS and HEL1OS) have observed the multiple X- and M-class flares from these regions during the last few days while the in-situ magnetometer (MAG) payload has also observed the events. “The observations made by SoLEXS, HEL1OS and MAG payloads are presented in Figures 3, 4 and 5 respectively,” Isro said.
Chandrayaan-2 observations
“Chandrayaan-2 orbiter’s X-ray Monitor (XSM) observed many interesting phenomena associated with a geomagnetic storm. It captured solar X-ray flux, autonomously identified large solar flares, and monitored the local high-energy particle environment by counting events when the upper level discriminator threshold was crossed,” Isro said.
It added that XSM’s data revealed an enhancement in local charge particle concentration from May 9 onwards, with dips due to the spacecraft’s orbital motion around the Moon.
The resulting geomagnetic storm was the strongest since 2003, causing disruptions to communication and GPS systems, especially at high latitudes.“…This storm was comparable to the historic Carrington Event of 1859, with trans-polar flights diverted and effects concentrated over high latitudes in the Pacific and American sectors,” Isro said.
Spacecraft OK
“No major upsets or anomalies were reported in Isro’s 30 GEO spacecrafts or Earth Observation Satellites. However, the increased atmospheric density caused by the solar event led to increased orbit decay, with some satellites experiencing 5-6 times higher decay compared to nominal values on May 11, 2024,” Isro said.
It added that its navigation centre has not noticed any significant degradation in the NaVIC service metrics till now, indicating no or negligible impact from the geomagnetic storm.
Ground observations
Observations from ground during the early morning hours of May 11 in India revealed a decrease of over 50% in Total Electron Content (TEC) at NARL, Gadanki, indicating an underdeveloped ionosphere.
“Daytime TEC was high by about 10% with large variations, while evening TEC was nearly 30% more, with no L-band scintillation or bubbles observed. At Thumba, the TEC values sharply enhanced, leading to over 100% increase compared to the control day, reaching around 80 TECu by 9am, which is significantly higher than typical values of 10-20 TECu at that time,” Isro said.
Aditya-L1 observations
Isro mobilised all its observation platforms and systems to record the signatures of this event. Both Aditya-L1 and Chandrayaan-2 have made observations and signatures have been analysed.
“Aditya-L1 spacecraft, situated at the L1 point, recorded high-speed solar wind, high-temperature plasma, and energetic ion flux associated with the CMEs using its ASPEX payload. The X-ray instruments on Aditya-L1 also captured the powerful X-class flares, while the magnetometer detected perturbations in the interplanetary magnetic field,” Isro said.
The X-ray payloads on-board Aditya-L1 (SoLEXS and HEL1OS) have observed the multiple X- and M-class flares from these regions during the last few days while the in-situ magnetometer (MAG) payload has also observed the events. “The observations made by SoLEXS, HEL1OS and MAG payloads are presented in Figures 3, 4 and 5 respectively,” Isro said.
Chandrayaan-2 observations
“Chandrayaan-2 orbiter’s X-ray Monitor (XSM) observed many interesting phenomena associated with a geomagnetic storm. It captured solar X-ray flux, autonomously identified large solar flares, and monitored the local high-energy particle environment by counting events when the upper level discriminator threshold was crossed,” Isro said.
It added that XSM’s data revealed an enhancement in local charge particle concentration from May 9 onwards, with dips due to the spacecraft’s orbital motion around the Moon.