Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 35, 1219-1229, 2017
https://doi.org/10.5194/angeo-35-1219-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Regular paper
10 Nov 2017
Unusual behavior of quiet-time zonal and vertical plasma drift velocities over Jicamarca during the recent extended solar minimum of 2008
Ângela M. Santos1, Mangalathayil A. Abdu1,2, Jonas R. Souza1, Inez S. Batista1, and José H. A. Sobral1 1Divisão de Aeronomia, Instituto Nacional de Pesquisas Espaciais, São José dos Campos, 12227-010, São Paulo, Brazil
2Instituto Tecnológico de Aeronáutica (ITA), DCTA, São Jose dos Campos, Brazil
Abstract. The influence of the recent deep and prolonged solar minimum on the daytime zonal and vertical plasma drift velocities during quiet time is investigated in this work. Analyzing the data obtained from incoherent scatter radar from Jicamarca (11.95° S, 76.87° W) we observe an anomalous behavior of the zonal plasma drift during June 2008 characterized by lower than usual daytime westward drift and its early afternoon reversal to eastward. As a case study the zonal drift observed on 24 June 2008 is modeled using a realistic low-latitude ionosphere simulated by the Sheffield University Plasmasphere-Ionosphere Model-INPE (SUPIM-INPE). The results show that an anomalously low zonal wind was mainly responsible for the observed anomalous behavior in the zonal drift. A comparative study of the vertical plasma drifts obtained from magnetometer data for some periods of maximum (2000–2002) and minimum solar activity (1998, 2008, 2010) phases reveal a considerable decrease on the E-region conductivity and the dynamo electric field during 2008. However, we believe that the contribution of these characteristics to the unusual behavior of the zonal plasma drift is significantly smaller than that arising from the anomalously low zonal wind. The SUPIM-INPE result of the critical frequency of the F layer (foF2) over Jicamarca suggested a lower radiation flux than that predicted by solar irradiance model (SOLAR2000) for June 2008.

Citation: Santos, Â. M., Abdu, M. A., Souza, J. R., Batista, I. S., and Sobral, J. H. A.: Unusual behavior of quiet-time zonal and vertical plasma drift velocities over Jicamarca during the recent extended solar minimum of 2008, Ann. Geophys., 35, 1219-1229, https://doi.org/10.5194/angeo-35-1219-2017, 2017.
Publications Copernicus
Download
Short summary
This paper analyzes the influence of the recent deep and prolonged solar minimum on the daytime zonal and vertical plasma drift velocities during quiet time over Jicamarca, Peru. Our results show that an anomalously low zonal wind was mainly responsible for the observed anomalous behavior in the zonal drift followed by a decrease in the E-region conductivity and the dynamo electric field during 2008.
This paper analyzes the influence of the recent deep and prolonged solar minimum on the daytime...
Share