Citation:
Cao, Y. T., Cui, J., Wu, X. S., and Zhong, J. H. (2020). Photoelectron pitch angle distribution near Mars and implications on cross terminator magnetic field connectivity. Earth Planet. Phys., 4(1), 17–22.doi: 10.26464/epp2020008
2020, 4(1): 17-22. doi: 10.26464/epp2020008
Photoelectron pitch angle distribution near Mars and implications on cross terminator magnetic field connectivity
| 1. | Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China |
| 2. | School of Astronomy and Space Sciences, University of Chinese Academy of Sciences, Beijing 100049, China |
| 3. | School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai Guangdong 519082, China |
| 4. | Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, Hefei 230026, China |
The photoelectron peak at 22–27 eV, a distinctive feature of the energetic electron distribution in the dayside Martian ionosphere, is a useful diagnostic of solar extreme ultraviolet (EUV) and X-ray ionization as well as of large-scale transport along magnetic field lines. In this work, we analyze the pitch angle distribution (PAD) of energetic electrons at 22–27 eV measured during several representative Mars Atmosphere and Volatile Evolution (MAVEN) orbits, based on the electron spectra gathered by MAVEN’s Solar Wind Electron Analyzer (SWEA) instrument. On the dayside, most photoelectron spectra show an isotropic PAD as is expected from production via solar EUV/X-ray ionization. The photoelectron spectra occasionally observed on the nightside show instead a strongly anisotropic PAD, indicative of cross-terminator transport along ambient magnetic field lines. This would in turn predict the presence of dayside photoelectrons, also with a strongly anisotropic PAD, which was indeed revealed in SWEA data. Comparison with magnetic field measurements made by the MAVEN Magnetometer suggests that on average the photoelectrons with anisotropic PAD stream away from Mars on the dayside and towards Mars on the nightside, further supporting the scenario of day-to-night transport. On both sides, anisotropic photoelectrons tend to be observed above the photoelectron exobase at ~160 km where photoelectron transport dominates over local production and energy degradation.
|
Cao, Y. T., Cui, J., Wu, X. S., Guo, J. P., and Wei, Y. (2019). Structural variability of the Nightside Martian ionosphere near the terminator: Implications on plasma sources. J. Geophys. Res. Planets, 124(6), 1495–1511. https://doi.org/10.1029/2019JE005970 |
|
Coates, A. J., Tsang, S. M. E., Wellbrock, A., Frahm, R. A., Winningham, J. D., Barabash, S., Lundin, R., Young, D. T., and Crary, F. J. (2011). Ionospheric photoelectrons: Comparing Venus, Earth, Mars and Titan. Planet. Space Sci., 59(10), 1019–1027. https://doi.org/10.1016/j.pss.2010.07.016 |
|
Connerney, J. E. P., Espley, J., Lawton, P., Murphy, S., Odom, J., Oliversen, R., and Sheppard, D. (2015). The MAVEN magnetic field investigation. Space Sci. Rev., 195(1-4), 257–291. https://doi.org/10.1007/s11214-015-0169-4 |
|
Cui, J., Galand, M., Yelle, R. V., Vuitton, V., Wahlund, J. E., Lavvas, P. P., Müller-Wodarg, I. C. F., Cravens, T. E., Kasprzak, W. T., and Waite, Jr. J. H. (2009). Diurnal variations of Titan’s ionosphere. J. Geophys. Res. Space Phys., 114(A6), A06310. https://doi.org/10.1029/2009JA014228 |
|
Cui, J., Galand, M., Yelle, R. V., Wahlund, J. E., Ågren, K., Waite, Jr. J. H., and Dougherty, M. K. (2010). Ion transport in Titan’s upper atmosphere. J. Geophys. Res. Space Phys., 115(A6), A06314. https://doi.org/10.1029/2009JA014563 |
|
Cui, J., Galand, M., Yelle, R. V., Wei, Y., and Zhang, S. J. (2015). Day-to-night transport in the Martian ionosphere: Implications from total electron content measurements. J. Geophys. Res. Space Phys., 120(3), 2333–2346. https://doi.org/10.1002/2014JA020788 |
|
Cui, J., Cao, Y. T., Wu, X. S., Xu, S. S., Yelle, R. V., Stone, S., Vigren, E., Edberg, N. J. T., Shen, C. L., … Wei, Y. (2019). Evaluating local ionization balance in the Nightside Martian upper atmosphere during MAVEN deep dip campaigns. Astrophys. J. Lett., 876(1), L12. https://doi.org/10.3847/2041-8213/ab1b34 |
|
Duru, F., Gurnett, D. A., Morgan, D. D., Winningham, J. D., Frahm, R. A., and Nagy, A. F. (2011). Nightside ionosphere of Mars studied with local electron densities: A general overview and electron density depressions. J. Geophys. Res. Space Phys., 116(A10), A10316. https://doi.org/10.1029/2011JA016835 |
|
Fowler, C. M., Andersson, L., Ergun, R. E., Morooka, M., Delory, G., Andrews, D. J., Lillis, R. J., McEnulty, T., Weber, T. D., … Jakosky, B. M. (2015). The first in situ electron temperature and density measurements of the Martian nightside ionosphere. Geophys. Res. Lett., 42(21), 8854–8861. https://doi.org/10.1002/2015GL065267 |
|
Fox, J. L., Brannon, J. F., and Porter, H. S. (1993). Upper limits to the nightside ionosphere of Mars. Geophys. Res. Lett., 20(13), 1339–1342. https://doi.org/10.1029/93GL01349 |
|
Frahm, R. A., Winningham, J. D., Sharber, J. R., Scherrer, J. R., Jeffers, S. J., Coates, A. J., Linder, D. R., Kataria, D. O., Lundin, R., … Dierker, C. (2006). Carbon dioxide photoelectron energy peaks at Mars. Icarus, 182(2), 371–382. https://doi.org/10.1016/j.icarus.2006.01.014 |
|
Knudsen, W. C., Spenner, K., Miller, K. L., and Novak, V. (1980). Transport of ionospheric O+ ions across the Venus terminator and implications. J. Geophys. Res. Space Phys., 85(A13), 7803–7810. https://doi.org/10.1029/JA085iA13p07803 |
|
Knudsen, W. C., and Miller, K. L. (1992). The Venus transterminator ion flux at solar maximum. J. Geophys. Res. Space Phys., 97(A11), 17165–17167. https://doi.org/10.1029/92JA01460 |
|
Lillis, R. J., Fillingim, M. O., Peticolas, L. M., Brain, D. A., Lin, R. P., and Bougher, S. W. (2009). Nightside ionosphere of Mars: Modeling the effects of crustal magnetic fields and electron pitch angle distributions on electron impact ionization. J. Geophys. Res. Planets, 114(E11), E11009. https://doi.org/10.1029/2009JE003379 |
|
Lillis, R. J., Fillingim, M. O., and Brain, D. A. (2011). Three-dimensional structure of the Martian nightside ionosphere: Predicted rates of impact ionization from Mars Global Surveyor magnetometer and electron reflectometer measurements of precipitating electrons. J. Geophys. Res. Space Phys., 116(A12), A12317. https://doi.org/10.1029/2011JA016982 |
|
Lillis, R. J., and Brain, D. A. (2013). Nightside electron precipitation at Mars: Geographic variability and dependence on solar wind conditions. J. Geophys. Res. Space Phys., 118(6), 3546–3556. https://doi.org/10.1002/jgra.50171 |
|
Lillis, R. J., Mitchell, D. L., Steckiewicz, M., Brain, D., Xu, S. S., Weber, T., Halekas, J., Connerney, J., Espley, J., … Eparvier, F. (2018). Ionizing electrons on the Martian Nightside: structure and variability. J. Geophys. Res. Space Phys., 123(5), 4349–4363. https://doi.org/10.1029/2017JA025151 |
|
Mantas, G. P., and Hanson, W. B. (1979). Photoelectron fluxes in the Martian ionosphere. J. Geophys. Res. Space Phys., 84(A2), 369–385. https://doi.org/10.1029/JA084iA02p00369 |
|
Mitchell, D. L., Mazelle, C., Sauvaud, J. A., Thocaven, J. J., Rouzaud, J., Fedorov, A., Rouger, P., Toublanc, D., Taylor, E., … Jakosky, B. M. (2016). The MAVEN solar wind electron analyzer. Space Sci. Rev., 200(1-4), 495–528. https://doi.org/10.1007/s11214-015-0232-1 |
|
Němec, F., Morgan, D. D., Gurnett, D. A., and Duru, F. (2010). Nightside ionosphere of Mars: Radar soundings by the Mars Express spacecraft. J. Geophys. Res. Planets, 115(E12), E12009. https://doi.org/10.1029/2010JE003663 |
|
Peterson, W. K., Thiemann, E., M. B., Eparvier, F. G., Andersson, L., Fowler, C. M., Larson, D., Mitchell, D., Mazelle, C., Fontenla, J., … Jakosky, B. (2016). Photoelectrons and solar ionizing radiation at Mars: Predictions versus MAVEN observations. J. Geophys. Res. Space Phys., 121(9), 8859–8870. https://doi.org/10.1002/2016JA022677 |
|
Sakai, S., Rahmati, A., Mitchell, D. L., Cravens, T. E., Bougher, S. W., Mazelle, C., Peterson, W. K., Eparvier, F. G., Fontenla, J. M., and Jakosky, B. M. (2015). Model insights into energetic photoelectrons measured at Mars by MAVEN. Geophys. Res. Lett., 42(21), 8894–8900. https://doi.org/10.1002/2015GL065169 |
|
Spenner, K., Knudsen, W. C., Whitten, R. C., Michelson, P. F., Miller, K. L., and Novak, V. (1981). On the maintenance of the Venus nightside ionosphere: Electron precipitation and plasma transport. J. Geophys. Res. Space Phys., 86(A11), 9170–9178. https://doi.org/10.1029/JA086iA11p09170 |
|
Steckiewicz, M., Mazelle, C., Garnier, P., André, N., Penou, E., Beth, A., Sauvaud, J. A., Toublanc, D., Mitchell, D. L., … Jakosky, B. M. (2015). Altitude dependence of nightside Martian suprathermal electron depletions as revealed by MAVEN observations. Geophys. Res. Lett., 42(21), 8877–8884. https://doi.org/10.1002/2015GL065257 |
|
Steckiewicz, M., Garnier, P., André, N., Mitchell, D. L., Andersson, L., Penou, E., Beth, A., Fedorov, A., Sauvaud, J. A., … Jakosky, B. M. (2017). Comparative study of the Martian suprathermal electron depletions based on Mars Global Surveyor, Mars Express, and Mars Atmosphere and volatile evolution mission observations. J. Geophys. Res. Space Phys., 122(1), 857–873. https://doi.org/10.1002/2016JA023205 |
|
Verigin, M. I., Gringauz, K. I., Shutte, N. M., Haider, S. A., Szego, K., Kiraly, P., Nagy, A. F., and Gombosi, T. I. (1991). On the possible source of the ionization in the nighttime Martian ionosphere: 1. Phobos 2 Harp electron spectrometer measurements. J. Geophys. Res. Space Phys., 96(A11), 19307–19313. https://doi.org/10.1029/91JA00924 |
|
Weber, T., Brain, D., Mitchell, D., Xu, S. S., Connerney, J., and Halekas, J. (2017). Characterization of low-altitude nightside Martian magnetic topology using electron pitch angle distributions. J. Geophys. Res. Space Phys., 122(10), 9777–9789. https://doi.org/10.1002/2017JA024491 |
|
Withers, P. (2009). A review of observed variability in the dayside ionosphere of Mars. Adv. Space Res., 44(3), 277–307. https://doi.org/10.1016/j.asr.2009.04.027 |
|
Withers, P., Fillingim, M. O., Lillis, R. J., Häusler, B., Hinson, D. P., Tyler, G. L., Pätzold, M., Peter, K., Tellmann, S., and Witasse, O. (2012). Observations of the nightside ionosphere of Mars by the Mars Express Radio Science Experiment (MaRS). J. Geophys. Res. Space Phys., 117(A12), A12307. https://doi.org/10.1029/2012JA018185 |
|
Wu, X. S., Cui, J., Yu, J., Liu, L. J., and Zhou, Z. J. (2019). Photoelectron balance in the dayside Martian upper atmosphere. Earth Planet. Phys., 3(5), 373–379. https://doi.org/10.26464/epp2019038 |
|
Xu, S. S., Mitchell, D., Liemohn, M., Dong, C. F., Bougher, S., Fillingim, M., Lillis, R., McFadden, J., Mazelle, C., … Jakosky, B. (2016). Deep nightside photoelectron observations by MAVEN SWEA: Implications for Martian northern hemispheric magnetic topology and nightside ionosphere source. Geophys. Res. Lett., 43(17), 8876–8884. https://doi.org/10.1002/2016GL070527 |
|
Xu, S. S., Mitchell, D., Liemohn, M., Fang, X. H., Ma, Y. J., Luhmann, J., Brain, D., Steckiewicz, Mazelle, M., … Jakosky, B. (2017a). Martian low-altitude magnetic topology deduced from MAVEN/SWEA observations. J. Geophys. Res. Space Phys., 122(2), 1831–1852. https://doi.org/10.1002/2016JA023467 |
|
Xu, S. S., Mitchell, D., Luhmann, J., Ma, Y. J., Fang, X. H., Harada, Y., Hara, T., Brain, D., Weber, T., … DiBraccio, G. A. (2017b). High-altitude closed magnetic loops at mars observed by MAVEN. Geophys. Res. Lett., 44(22), 11229–11238. https://doi.org/10.1002/2017GL075831 |
|
Xu, S. S., Weber, T., Mitchell, D. L., Brain, D. A., Mazelle, C., DiBraccio, G. A., and Espley, J. (2019). A technique to infer magnetic topology at mars and its application to the terminator region. J. Geophys. Res. Space Phys., 124(3), 1823–1842. https://doi.org/10.1029/2018JA026366 |
|
Zhang, M. H. G., Luhmann, J. G., and Kliore, A. J. (1990). An observational study of the nightside ionospheres of Mars and Venus with radio occultation methods. J. Geophys. Res. Space Phys., 95(A10), 17095–17102. https://doi.org/10.1029/JA095iA10p17095 |
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