Multi-Instrument Analysis of NOAA AR 12781: Coupling Surface Evolution of the AR with Its In-Situ Solar Wind Signatures
Abstract
Understanding the relationship between photospheric magnetic flux evolution and coronal emission remains an important problem in heliophysics. We investigate the decay of NOAA Active Region 12781 from 7 to 11 November 2020 using observations from the Solar Dynamics Observatory (SDO). Coronal emission was measured from the Atmospheric Imaging Assembly (AIA) 193\~Å images, while the photospheric signed and unsigned magnetic flux was derived from Helioseismic and Magnetic Imager (HMI) observations of the FeĨ 6173\~Å line. The unsigned magnetic flux and mean 193\~Å intensity showed a strong inverse relationship, with Pearson and Spearman correlation coefficients of r_p=−0.771 and r_s=−0.758, respectively. During the five-day decay phase, the unsigned magnetic flux decreased by 36.54\\% from its maximum value, while the coronal emission increased by 21.96\\%. We also compared the remote-sensing observations with near-Earth solar-wind and interplanetary magnetic-field measurements from the OMNI database using an estimated propagation delay. The results show that the coronal emission did not vary directly with the photospheric magnetic flux during the decay of AR\~12781. The possible association with the solar wind is discussed cautiously because a direct source connection cannot be established from the time-delay estimate alone.
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BibTeX
@misc{palaniappan2026multiinstrument,
title = {{Multi-Instrument Analysis of NOAA AR 12781: Coupling Surface Evolution of the AR with Its In-Situ Solar Wind Signatures}},
author = {Dharanesh Palaniappan and Khagendra Katuwal},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.13689},
eprint = {2609.13689},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.13689},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Multi-Instrument Analysis of NOAA AR 12781: Coupling Surface Evolution of the AR with Its In-Situ Solar Wind Signatures
AU - Dharanesh Palaniappan
AU - Khagendra Katuwal
PY - 2026
DA - 2026/09/12
PB - arXiv
DO - 10.48550/arxiv.2609.13689
UR - https://arxiv.org/abs/2609.13689
AB - Understanding the relationship between photospheric magnetic flux evolution and coronal emission remains an important problem in heliophysics. We investigate the decay of NOAA Active Region 12781 from 7 to 11 November 2020 using observations from the Solar Dynamics Observatory (SDO). Coronal emission was measured from the Atmospheric Imaging Assembly (AIA) 193\~Å images, while the photospheric signed and unsigned magnetic flux was derived from Helioseismic and Magnetic Imager (HMI) observations of the FeĨ 6173\~Å line. The unsigned magnetic flux and mean 193\~Å intensity showed a strong inverse relationship, with Pearson and Spearman correlation coefficients of r_p=−0.771 and r_s=−0.758, respectively. During the five-day decay phase, the unsigned magnetic flux decreased by 36.54\\% from its maximum value, while the coronal emission increased by 21.96\\%. We also compared the remote-sensing observations with near-Earth solar-wind and interplanetary magnetic-field measurements from the OMNI database using an estimated propagation delay. The results show that the coronal emission did not vary directly with the photospheric magnetic flux during the decay of AR\~12781. The possible association with the solar wind is discussed cautiously because a direct source connection cannot be established from the time-delay estimate alone.
ER -