posted on 2019-05-29, 14:52authored byB Hall, B Sanchez-Cano, W James, M Lester, M Holmstrom
The Martian bow shock position is known to be correlated with solar extreme ultraviolet (EUV) irradiance. Since this parameter is also correlated with the evolution of the solar cycle, it is expected the Martian bow shock position should also vary over such a period. However, previous reports on this topic have often proved contradictory. Using 13 years of observations of the Martian bow shock by the Mars Express mission over the period 2004 to 2017, we report that the Martian bow shock position does vary over the solar cycle. Over this period our analysis shows the bow shock position to increase on average by 7% between the solar minimum and maximum phases of solar cycle 23‐24, which could be even larger for more extreme previous solar cycles. We show that both annual and solar cycle variations play major roles in the location of the bow shock at Mars.
Funding
BESH acknowledges previous support through STFC grant ST/K502121/1 and also
through ST/M001059/1, JW also from STFC grant ST/M001059/1, ML and BS‐C through
STFC grant ST/N000749/1. The Swedish contribution to the ASPERA‐3 experiment is
supported by funding from the Swedish National Space Agency (SNSA). The MEX
ASPERA‐3 datasets are hosted on the European Space Agency's Planetary Science Archive, and we thank the mission/instrument PIs, and the database managers for their support of the MEX mission. The derived bow shock crossing list in this study is hosted and available from the Lancaster University Research Directory with DOI: https://doi.org/10.17635/lancaster/researchdata/285. The TIMED‐SEE data was
downloaded from the University of Colorado’s website (http://lasp.colorado.edu/lisird/index.html) and we thank the PIs for access to this
dataset. The OMNI 2 dataset are available on the GSFC/SPDF OMNIWeb platform (http://cdaweb.gsfc.nasa.gov/) and we are grateful to the PIs for the creation and maintenance of this vast dataset. The authors thank the Mars Upper Atmosphere Network led by Hermann J. Opgenoorth for rich discussions at their semi‐annual meetings. BESH, whom has since left academia to pursue other ventures, would personally like to thank the hard work, commitment, and leadership of BS‐C as they took ownership of this publication throughout the review process enabling it to reach its final publishable state.
History
Citation
Journal of Geophysical Research: Space Physics, 2019
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy