EGU2020-5276
https://doi.org/10.5194/egusphere-egu2020-5276
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Solar quiet daily (Sq) geomagnetic variation during minimum of solar cycle 23/24

Anatoly Soloviev1,2 and Artem Smirnov1,3
Anatoly Soloviev and Artem Smirnov
  • 1Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
  • 2Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow, Russia
  • 3GFZ German Research Centre for Geosciences, Potsdam, Germany

The most regular of all daily geomagnetic field variations is the so-called solar quiet, or Sq, variation. It is attributed to the two current vortices flowing in the E-region of the dayside ionosphere. We present an investigation of the time-dependent parameters of Sq variation for the historical minimum of solar activity in 2008. We apply "Measure of Anomalousness" algorithm to detection of magnetically quiet days. The global maps of seasonal Sq amplitudes of the three orthogonal components are derived using 75 INTERMAGNET and 46 SuperMAG stations at low and middle latitudes. The global Sq amplitudes are compared to the previous Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model simulations and show good agreement. Significant variability was found in Sq(X) and Sq(Y) based on the solar activity and latitude, while almost no difference is observed in Sq(Z) for across all latitudes and seasons. We analyze equivalent Sq current system using observatory data from the Australian mainland and narrow European-African latitudinal segment. Sq current system also strongly depends on solar activity, as current vortices are strongest in the local summer-hemisphere and disintegrate during local winter. The dynamics of Sq variation along the solar cycles 23 and 24 is also discussed and compared to Swarm-based spherical harmonic Sq model.

How to cite: Soloviev, A. and Smirnov, A.: Solar quiet daily (Sq) geomagnetic variation during minimum of solar cycle 23/24, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5276, https://doi.org/10.5194/egusphere-egu2020-5276, 2020

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