Nonlinear Processes in Geophysics
Nonlinear Processes in Geophysics
NPG
Articles | Volume 9, issue 5/6
Articles | Volume 9, issue 5/6
https://doi.org/10.5194/npg-9-443-2002
© Author(s) 2002. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
Special issue:
https://doi.org/10.5194/npg-9-443-2002
© Author(s) 2002. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
Articles | Volume 9, issue 5/6
31 Dec 2002
 | 31 Dec 2002

On the properties of turbulent boundary layer over polar cusps

S. Savin, J. Büchner, G. Consolini, B. Nikutowski, L. Zelenyi, E. Amata, H. U. Auster, J. Blecki, E. Dubinin, K. H. Fornacon, H. Kawano, S. Klimov, F. Marcucci, Z. Nemecek, A. Pedersen, J. L. Rauch, S. Romanov, J. Safrankova, J. A. Sauvaud, A. Skalsky, P. Song, and Yu. Yermolaev

Abstract. We study properties of nonlinear magnetic fluctuations in the turbulent boundary layer (TBL) over polar cusps during a typical TBL crossing on 19 June 1998. Interball-1data in the summer TBL are compared with that of Geotail in solar wind (SW) and Polar in the northern TBL. In the TBL two characteristic slopes are seen: ~ - 1 at (0.004- 0.08) Hz and ~ - 2.2 at (0.08-2) Hz. We present evidences that random current sheets with features of coherent solitons can result in: (i) slopes of ~ - 1 in the magnetic power spectra; (ii) demagnetization of the SW plasma in "diamagnetic bubbles"; (iii) nonlinear, presumably, 3-wave phase coupling with cascade features; (iiii) departure from the Gaussian statistics. We discuss the above TBL properties in terms of intermittency and self-organization of nonlinear systems, and compare them with kinetic simulations of reconnected current sheet at the nonlinear state. Virtual satellite data in the model current sheet reproduce valuable cascade-like spectral and bi-spectral properties of the TBL turbulence.

How to cite. Savin, S., Büchner, J., Consolini, G., Nikutowski, B., Zelenyi, L., Amata, E., Auster, H. U., Blecki, J., Dubinin, E., Fornacon, K. H., Kawano, H., Klimov, S., Marcucci, F., Nemecek, Z., Pedersen, A., Rauch, J. L., Romanov, S., Safrankova, J., Sauvaud, J. A., Skalsky, A., Song, P., and Yermolaev, Yu.: On the properties of turbulent boundary layer over polar cusps, Nonlin. Processes Geophys., 9, 443–451, https://doi.org/10.5194/npg-9-443-2002, 2002.