| Title | Forecasting the ambient solar wind with numerical models. I. On the implementation of an operational framework |
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| Author | Reiss, M A; MacNeice, P J; Mays, L M; Arge, C N; Möstl, C; Nikolic, L; Amerstorfer, T |
| Source | The Astrophysical Journal, Supplement Series vol. 240, no. 2, 35, 2019 p. 1-13, https://doi.org/10.3847/1538-4365/aaf8b3  Open Access |
| Image |  |
| Year | 2019 |
| Alt Series | Natural Resources Canada, Contribution Series 20180437 |
| Publisher | American Astronomical Society |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | geophysics; extraterrestrial geology; geomagnetism; models; magnetic field; magnetic storms; Environmental hazards; Forecasting |
| Illustrations | models; flow diagrams; models; sketch maps; 3-D models; graphs; time series; tables |
| Program | Public Safety Geoscience Northern Canada Geohazards Project |
| Released | 2019 02 12 |
| Abstract | The ambient solar wind conditions in interplanetary space and in the near-Earth environment are determined by activity on the Sun. Steady solar wind streams modulate the propagation behavior of
interplanetary coronal mass ejections and are themselves an important driver of recurrent geomagnetic storm activity. The knowledge of the ambient solar wind flows and fields is thus an essential component of successful space weather forecasting.
Here, we present an implementation of an operational framework for operating, validating, and optimizing models of the ambient solar wind flow on the example of Carrington Rotation 2077. We reconstruct the global topology of the coronal magnetic
field using the potential field source surface model (PFSS) and the Schatten current sheet model (SCS) and discuss three empirical relationships for specifying the solar wind conditions near the Sun, namely the Wang-Sheeley (WS) model, the distance
from the coronal hole boundary model (DCHB), and the Wang-Sheeley-Arge (WSA) model. By adding uncertainty in the latitude about the sub-Earth point, we select an ensemble of initial conditions and map the solutions to Earth by the Heliospheric Upwind
eXtrapolation (HUX) model. We assess the forecasting performance from a continuous variable validation and find that the WSA model most accurately predicts the solar wind speed time series (RMSE approx. equal to 83 km/s). We note that the process of
ensemble forecasting slightly improves the forecasting performance of all solar wind models investigated. We conclude that the implemented framework is well suited for studying the relationship between coronal magnetic fields and the properties of
the ambient solar wind flow in the near-Earth environment. |
| Summary | (Plain Language Summary, not published)
Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment, that can affect
critical infrastructure. NRCan operates the Canadian Space Weather Forecast Centre and conducts research into space weather effects on power systems, pipelines, radio communications and GNSS positioning to help Canadian industry understand and
mitigate the effects of space weather. The interaction of the solar wind with the Earth's magnetic field can affect the intensity and direction of the magnetic field. This work deals with the numerical modelling which aims to provide operational
forecast of the solar wind speed. |
| GEOSCAN ID | 314536 |
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