In situ measurements of interplanetary coronal mass ejection(ICME)composition,including elemental abundances and charge states of heavy ions,open a new avenue to study coronal mass ejections(CMEs)besides remote-sensin...In situ measurements of interplanetary coronal mass ejection(ICME)composition,including elemental abundances and charge states of heavy ions,open a new avenue to study coronal mass ejections(CMEs)besides remote-sensing observations.The ratios between different elemental abundances can diagnose the plasma origin of CMEs(e.g.,from the corona or chromosphere/photosphere)due to the first ionization potential(FIP)effect,which means elements with different FIPs get fractionated between the photosphere and corona.The ratios between different charge states of a specific element can provide the electron temperature of CMEs in the corona due to the freeze-in effect,which can be used to investigate their eruption process.In this review,we first give an overview of the ICME composition and then demonstrate their applications in investigating some important subjects related to CMEs,such as the origin of filament plasma and the eruption process of magnetic flux ropes.Finally,we point out several important questions that should be addressed further for better utilizing the ICME composition to study CMEs.展开更多
基金This work was supported by the Shandong Provincial Natural Science Foun-dation(Grant No.JQ201710)the National Natural Science Foundation of China(Grant Nos.U1731102,U1731101,11790303,and 11790300)and the Chinese Academy of Sciences(Grant No.XDA-17040507).
文摘In situ measurements of interplanetary coronal mass ejection(ICME)composition,including elemental abundances and charge states of heavy ions,open a new avenue to study coronal mass ejections(CMEs)besides remote-sensing observations.The ratios between different elemental abundances can diagnose the plasma origin of CMEs(e.g.,from the corona or chromosphere/photosphere)due to the first ionization potential(FIP)effect,which means elements with different FIPs get fractionated between the photosphere and corona.The ratios between different charge states of a specific element can provide the electron temperature of CMEs in the corona due to the freeze-in effect,which can be used to investigate their eruption process.In this review,we first give an overview of the ICME composition and then demonstrate their applications in investigating some important subjects related to CMEs,such as the origin of filament plasma and the eruption process of magnetic flux ropes.Finally,we point out several important questions that should be addressed further for better utilizing the ICME composition to study CMEs.