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Title: Connecting speeds, directions and arrival times of 22 coronal mass ejections from the sun to 1 AU

Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to 2700 km s{sup –1}). We track the CMEs to 34.9 ± 7.1 deg elongation from the Sun with J maps constructed using the SATPLOT tool, resulting in prediction lead times of –26.4 ± 15.3 hr. The geometrical models we use assume different CME front shapes (fixed-Φ, harmonic mean, self-similar expansion) and constant CME speed and direction. We find no significant superiority in the predictive capability of any of the three methods. The absolute difference between predicted and observed ICME arrival times is 8.1 ± 6.3 hr (rmsmore » value of 10.9 hr). Speeds are consistent to within 284 ± 288 km s{sup –1}. Empirical corrections to the predictions enhance their performance for the arrival times to 6.1 ± 5.0 hr (rms value of 7.9 hr), and for the speeds to 53 ± 50 km s{sup –1}. These results are important for Solar Orbiter and a space weather mission positioned away from the Sun-Earth line.« less
Authors:
; ; ; ;  [1] ; ; ; ;  [2] ;  [3] ; ;  [4] ; ; ;  [5] ;  [6] ;  [7] ;  [8]
  1. Kanzelhöhe Observatory-IGAM, Institute of Physics, University of Graz (Austria)
  2. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)
  3. Space Sciences Division, Naval Research Laboratory, Washington, DC (United States)
  4. RAL Space, Harwell Oxford, Didcot (United Kingdom)
  5. Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States)
  6. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China)
  7. Space Science Laboratory, University of California, Berkeley, CA (United States)
  8. Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kačićeva 26, HR-10000, Zagreb (Croatia)
Publication Date:
OSTI Identifier:
22356792
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 787; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; CORRECTIONS; DENSITY; ELONGATION; EXPANSION; FASTENING; FORECASTING; HELIOSPHERE; IMAGES; INTERACTIONS; MASS; SOLAR WIND; SPACE; SUN; VELOCITY