Solar Wind—Magnetosphere Coupling During Radial Interplanetary Magnetic Field Conditions: Simultaneous Multi-Point Observations Toledo Redondo, S. Fornieles Callejón, Jesús Francisco Magnetosphere Magnetic reconnection Magnetopause (MP) Solar wind S. Toledo-Redondo and J. Fornieles acknowledge support of the Ministry of Economy and Competitiveness (MINECO) of Spain (grant FIS2017-90102-R) and of Ministry of Science and Innovation (grant PID2020-112805GA-I00). Research at IRAP was supported by CNRS, CNES, and the University of Toulouse. We acknowledge support of the ISSI teams MMS and Cluster observations of magnetic reconnection and Cold plasma of ionospheric in the Earth's magnetosphere, and of the ESAC Science faculty. In-situ spacecraft missions are powerful assets to study processes that occur in space plasmas. One of their main limitations, however, is extrapolating such local measurements to the global scales of the system. To overcome this problem at least partially, multi-point measurements can be used. There are several multi-spacecraft missions currently operating in the Earth's magnetosphere, and the simultaneous use of the data collected by them provides new insights into the large-scale properties and evolution of magnetospheric plasma processes. In this work, we focus on studying the Earth's magnetopause (MP) using a conjunction between the Magnetospheric Multiscale and Cluster fleets, when both missions skimmed the MP for several hours at distant locations during radial interplanetary magnetic field (IMF) conditions. The observed MP positions as a function of the evolving solar wind conditions are compared to model predictions of the MP. We observe an inflation of the magnetosphere (similar to 0.7 R-E), consistent with magnetosheath pressure decrease during radial IMF conditions, which is less pronounced on the flank (<0.2 R-E). There is observational evidence of magnetic reconnection in the subsolar region for the whole encounter, and in the dusk flank for the last portion of the encounter, suggesting that reconnection was extending more than 15 R-E. However, reconnection jets were not always observed, suggesting that reconnection was patchy, intermittent or both. Shear flows reduce the reconnection rate up to similar to 30% in the dusk flank according to predictions, and the plasma beta enhancement in the magnetosheath during radial IMF favors reconnection suppression by the diamagnetic drift. 2021-12-13T08:20:03Z 2021-12-13T08:20:03Z 2021-11-07 info:eu-repo/semantics/article Toledo-Redondo, S... [et al.] (2021). Solar wind—Magnetosphere coupling during radial interplanetary magnetic field conditions: Simultaneous multi-point observations. Journal of Geophysical Research: Space Physics, 126, e2021JA029506. [https://doi.org/10.1029/2021JA029506] http://hdl.handle.net/10481/72025 10.1029/2021JA029506 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España American Geophysical Union