CATHI A New Operational Tool CME Analysis Tool

CAT-HI: A New Operational Tool CME Analysis Tool with Heliospheric Imagery S. J. Wharton 1, 3, G. H. Millward 2, S. Bingham 1, E. M. Henley 1, S. Gonzi 1 and D. R. Jackson 1 Contact SJW @ sjw 136@le. ac. uk 1: The Met Office, Exeter, UK 2: National Oceanic and Atmospheric Administration, Colorado, USA 3: University of Leicester, UK S. J. Wharton would like to acknowledge funding from the Central England NERC Training Alliance (CENTA) that enabled this placement to occur.

2/11 The Role of the CME Analysis Tool (CAT) Measure CME Initial Direction and Speed - CAT Physical Modelling of CME Propagation to get Time of Arrival – Enlil Measure ambient solar wind speed – WSA model CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

3/11 CAT Millward et al. (2013) CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

4/11 CAT-HI HI-1 HI-2 CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

5/11 Performance of CAT-HI vs CAT Initial parameters of CMEs Difference in Enlil start time No. of Images Used Initial parameter determination is consistent between CAT and CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

6/11 Measuring the Leading Edge/Acceleration Time zero (black line) is where the initial parameters for the Enlil solar wind model are defined. CAT-HI allows CME tracking far beyond the Enlil inner boundary. Tested for significant acceleration: - 3/13 CMEs for CAT - 8/13 CMEs for CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

7/11 Time of Arrival Enlil killing a sun goddess Enlil working out CME’s time of arrival Adding HI-1 imagery did not improve initial time of arrival predictions for this study on 13 CMEs. CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

8/11 STEREO limitations: Beacon vs. Science Beacon images available in near real-time but poorer resolution More science quality images available CAT-HI used science-quality images for this study. (Can use beacon) Any L 5 mission should have images to match STEREO’s science-quality. CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

9/11 Image Projection CAT-HI assumes that the images are flat like coronagraph’s plane of sky. Assumption breaks down for wide fields of view Geometrical analysis suggests the flat approximation is okay for HI 1 but not HI-2 CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

10/11 Advantages of CAT-HI Ensemble Modelling - MOSWOC’s current CME ensemble uses a uniform distribution. - Could use CAT-HI to prune ensemble forecasts Forecast Updates - Currently, no updates applied until CME is observed at L 1. - CAT-HI could be used to update projections before L 1. - Requires changes to Enlil e. g. Mays et al. (2015) CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019

11/11 Future of CAT-HI • Rewrite from IDL to freely-available Python • Add new features? • Citizen Science? • Undergraduate Projects? • Outreach? • Browser-based GUI? Wharton et al. (2019) [In review] Contact: sjw 136@le. ac. uk • Have operational for the Lagrange mission. CAT-HI: A New Operational Tool – S. J. Wharton et al. Preparing for when the Sun wakes up – 27 th-28 th June 2019