EGU21-1389
https://doi.org/10.5194/egusphere-egu21-1389
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Large scale thermospheric density enhancements in relation to downward Poynting fluxes: Statistics from CHAMP, AMPERE and SuperDARN

Daniel Billett1, Gareth Perry2, Lasse Clausen3, William Archer1, Kathryn McWilliams1, Stein Haaland4, and Johnathan Burchill5
Daniel Billett et al.
  • 1University of Saskatchewan, Institute of Space and Atmospheric Studies, Physics, Saskatoon, Canada (ddb524@usask.ca)
  • 2Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ, USA
  • 3Department of Physics, University of Oslo, Oslo, Norway
  • 4Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway
  • 5Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada

Large thermospheric neutral density enhancements in the cusp region have been examined for many years. The CHAMP satellite for example has enabled many observations of the perturbation, showing that it is mesoscale in size and exists on statistical timescales. Further studies examining the relationship with magnetospheric energy input have shown that fine-scale Poynting fluxes are associated with the density perturbations on a case-by-case basis, whilst others have found that mesoscale downward fluxes also exist in the cusp region statistically.

In this study, we use nearly 8 years of the overlapping SuperDARN and AMPERE datasets to generate global-scale patterns of the high-latitude and height-integrated Poynting flux into the ionosphere, with a time resolution of two minutes. From these, average patterns are generated based on the IMF orientation. We show the cusp is indeed an important feature in the Poynting flux maps, but the magnitude does not correlate well with statistical neutral mass density perturbations observed by the CHAMP satellite on similar spatial scales. Mesoscale height-integrated Poynting fluxes thus cannot fully account for the cusp neutral mass density enhancement, meaning energy deposition in the F-region or on fine-scales, which is not captured by our analysis, could be the primary driver.

How to cite: Billett, D., Perry, G., Clausen, L., Archer, W., McWilliams, K., Haaland, S., and Burchill, J.: Large scale thermospheric density enhancements in relation to downward Poynting fluxes: Statistics from CHAMP, AMPERE and SuperDARN, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1389, https://doi.org/10.5194/egusphere-egu21-1389, 2021.