2024-09-24T22:21:19.000Z http://sot.lmsal.com Mr. Sam Freeland Lockheed Martin Solar and Astrophysics Laboratory (LMSAL) http://www.lmsal.com Lockheed Martin Advanced Tech Center, 3251 Hanover Rd, O/ADBS, B/252, Palo Alto, CA 94304 null null HINODE SOTSP Kotanagi Shimojo Tiwari (RCO) 451 HOP 451 (AR 13326) Active Region AR AR 13326 14 20230609_115707 582 609 589 14 68 2000 2 1 1 2 0 21 2017 998 0.998 66.918 334.655 316.366 121.728 2023-06-09T11:57:07.000Z 2023-06-09T13:00:20.000Z 66.918 334.655 Plasma composition evolution in active region leading and following polarities Fast map, 328"x123", 1-side, Q65/75 Main Objective: Tracking the coronal composition (using Hinode EIS) and plasma temperature at chromospheric heights (using IRIS) in the leading and following polarities of an active region over a few days. Scientific Justification: Plasma composition (quantified using the FIP bias parameter) was found to be correlated to photospheric magnetic flux density (Baker et al., 2015; Mihailescu et al., 2022). Mihailescu et al. (2022) suggest that changes in magnetic flux density influence the plasma temperature at chromospheric heights which in turn influences the amount of ionized low FIP elements at those heights. This then has a direct impact on the FIP bias we measure in the corona. The proposed IHOP observations aim to test this idea by tracking an active region over a few days and simultaneously measuring its photospheric magnetic field (using SDO HMI), plasma temperature at chromospheric height (using IRIS) and coronal plasma composition (using Hinode EIS). Active region leading polarities tend to have more concentrated magnetic field than their following counterparts - we request tracking both polarities to cover a wider range of magnetic flux values.;;Main Objective: Tracking the coronal composition (using Hinode EIS) and plasma temperature at chromospheric heights (using IRIS) in the leading and following polarities of an active region over a few days. Scientific Justification: Plasma composition (quantified using the FIP bias parameter) was found to be correlated to photospheric magnetic flux density (Baker et al., 2015; Mihailescu et al., 2022). Mihailescu et al. (2022) suggest that changes in magnetic flux density influence the plasma temperature at chromospheric heights which in turn influences the amount of ionized low FIP elements at those heights. This then has a direct impact on the FIP bias we measure in the corona. The proposed IHOP observations aim to test this idea by tracking an active region over a few days and simultaneously measuring its photospheric magnetic field (using SDO HMI), plasma temperature at chromospheric height (using IRIS) and coronal plasma composition (using Hinode EIS). Active region leading polarities tend to have more concentrated magnetic field than their following counterparts - we request tracking both polarities to cover a wider range of magnetic flux values. ivo://sot.lmsal.com/VOEvent#2023-06-09T11:56:30Z