author = "Braga, Carlos Roberto and Vourlidas, Angelos and Dal Lago, Alisson 
                         and Mendon{\c{c}}a, Rafael Rodrigues Souza de and Echer, Ezequiel 
                         and Balmaceda, Laura and Kwon, Ryun Young",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Johns 
                         Hopkins University Applied Physics Laboratory} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Chinese Academy of 
                         Sciences} and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and {George Mason University} and {George Mason University 
                title = "What causes CME travel time estimation errors: their kinematic 
                         measurements in the corona or the limited understanding of the 
                         forces in their IP propagation?",
                 year = "2018",
         organization = "AGU Fall Meeting",
             abstract = "The coronal mass ejections (CME) time-of-arrival (ToA) estimates 
                         from the corona to 1 AU have been a topic of central interest due 
                         to the space weather phenomena associated with their arrival, such 
                         as intense geomagnetic storms. Several ToA estimates using 
                         kinematic input from white-light coronagraphs observations, both 
                         from a single and multi-viewpoint, have been made available, 
                         especially in the last decade. Despite of the development of many 
                         methods, ToA estimates errors are no better than 10 hours, on 
                         average. Our objective is to evaluate whether these discrepancies 
                         are associated with the limited analytical description of the 
                         forces acting on CMEs or with the improper kinematic input from 
                         observations. We took a set of well-observed CMEs from the Sun to 
                         1 AU and investigate possible reasons for the discrepancies. We 
                         considered that the CME propagation is controlled by the 
                         aerodynamic drag due to the background solar wind and the Lorentz 
                         forces. We discuss the discrepancies caused in the travel time 
                         estimate due to drag force in CMEs whose background solar wind 
                         conditions (such as speed) change dramatically in the period from 
                         the CME release until its arrival at 1 AU. We also estimate a 
                         possible force associated with the interaction of CMEs with 
                         interplanetary structures such as corotating interaction regions. 
                         Back-of-the-envelope calculations suggest that typical magnetic 
                         field and particle density observed in these structures could 
                         significantly change the CME velocity and lead to ToA errors. 
                         (This work is funded by FAPESP, Sao Paulo Research Foundation, 
                         grant #2017/21270-7).",
  conference-location = "Washington, D. C.",
      conference-year = "10-14 dec.",
             language = "en",
           targetfile = "abstract_carlos_agu_2018.pdf",
        urlaccessdate = "27 nov. 2020"