scholarly journals Design of the Heliospheric Imager for the STEREO mission

Author(s):  
Jean-Marc Defise ◽  
Jean-Philippe Halain ◽  
Emmanuel Mazy ◽  
Pierre P. Rochus ◽  
Russell A. Howard ◽  
...  
2018 ◽  
Vol 615 ◽  
pp. A143 ◽  
Author(s):  
G. Nisticò ◽  
V. Vladimirov ◽  
V. M. Nakariakov ◽  
K. Battams ◽  
V. Bothmer

Context. During their journey to perihelion, comets may appear in the field of view of space-borne optical instruments, showing in some cases a nicely developed plasma tail extending from their coma and exhibiting an oscillatory behaviour. Aims. The oscillations of cometary tails may be explained in terms of vortex shedding because of the interaction of the comet with the solar wind streams. Therefore, it is possible to exploit these oscillations in order to infer the value of the Strouhal number S t, which quantifies the vortex shedding phenomenon, and the physical properties of the local medium. Methods. We used the Heliospheric Imager (HI) data of the Solar TErrestrial Relations Observatory (STEREO) mission to study the oscillations of the tails of comets 2P/Encke and C/2012 S1 (ISON) during their perihelion in Nov 2013. We determined the corresponding Strouhal numbers from the estimates of the halo size, the relative speed of the solar wind flow, and the period of the oscillations. Results. We found that the estimated Strouhal numbers are very small, and the typical value of S t ~ 0.2 would be extrapolated for size of the halo larger than ~106 km. Conclusions. Although the vortex shedding phenomenon has not been unambiguously revealed, the findings suggest that some kind of magnetohydrodynamic (MHD) instability process is responsible for the observed behaviour of cometary tails, which can be exploited for probing the physical conditions of the near-Sun region.


2005 ◽  
Author(s):  
Emmanuel Mazy ◽  
Jean-Philippe Halain ◽  
Jean-Marc Defise ◽  
Philippe Ronchain ◽  
Russell A. Howard ◽  
...  

2021 ◽  
Author(s):  
Luke Barnard ◽  
Mat Owens ◽  
Chris Scott ◽  
Matt Lang

<p>Coronal Mass Ejections that impact Earth drive the most severe space weather. To better enable effective space weather mitigation plans, there is much interest in improving the quality of CME arrival time predictions, particularly by quantifying and reducing the prediction uncertainty. A limited set of observatories, challenges in interpreting observation data, and limiting assumptions in CME parameterisations all play important roles in the uncertainty of the predicted CME evolution.</p><p>Data assimilation techniques provide a path for improving the predictive skill, by integrating observations into a modelling framework in a way that returns model states that better reflect the true state of a system. Furthermore, such techniques can self-consistently account for uncertainty in the observations, and uncertainty in the models structure and parameterisations.</p><p>We present some early results from our work to build a particle filter data assimilation scheme around the HUXt solar wind model. Assimilating the time-elongation profiles of CME flanks observed by the Heliospheric Imagers on NASAs STEREO mission, we demonstrate that such methods have good potential to improve modelled CME arrival time predictions. Using a simulation study, we present an estimate of the potential CME arrival time prediction improvements gained by using this particle-filter approach with an L5 Heliospheric Imager.</p>


2003 ◽  
Author(s):  
Jean-Marc Defise ◽  
Jean-Philippe Halain ◽  
Emmanuel Mazy ◽  
Pierre P. Rochus ◽  
Russell A. Howard ◽  
...  

2007 ◽  
Author(s):  
Chris Eyles ◽  
Chris Davis ◽  
Richard Harrison ◽  
Nick Waltham ◽  
Jean-Philippe Halain ◽  
...  

2000 ◽  
Author(s):  
Dennis G. Socker ◽  
Russell A. Howard ◽  
Clarence M. Korendyke ◽  
George M. Simnett ◽  
David F. Webb

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Manuela Temmer

AbstractThe Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mission (launched in 2006), literally, new perspectives were provided that enabled for the first time to study coronal structures and the evolution of activity phenomena in three dimensions. New imaging capabilities, covering the entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their interplanetary counterparts measured in-situ (so called ICMEs). This vastly increased our knowledge and understanding of the dynamics of interplanetary space due to solar activity and fostered the development of Space Weather forecasting models. Moreover, we are facing challenging times gathering new data from two extraordinary missions, NASA’s Parker Solar Probe (launched in 2018) and ESA’s Solar Orbiter (launched in 2020), that will in the near future provide more detailed insight into the solar wind evolution and image CMEs from view points never approached before. The current review builds upon the Living Reviews article by Schwenn from 2006, updating on the Space Weather relevant CME-flare-SEP phenomena from the solar perspective, as observed from multiple viewpoints and their concomitant solar surface signatures.


2005 ◽  
Vol 36 (8) ◽  
pp. 1483-1488 ◽  
Author(s):  
M.L. Kaiser
Keyword(s):  

2007 ◽  
Vol 136 (1-4) ◽  
pp. 363-389 ◽  
Author(s):  
R. Müller-Mellin ◽  
S. Böttcher ◽  
J. Falenski ◽  
E. Rode ◽  
L. Duvet ◽  
...  
Keyword(s):  

Space Weather ◽  
2015 ◽  
Vol 13 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Kimberley Tucker‐Hood ◽  
Chris Scott ◽  
Mathew Owens ◽  
David Jackson ◽  
Luke Barnard ◽  
...  

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