Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 35, 161-170, 2017
https://doi.org/10.5194/angeo-35-161-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Regular paper
30 Jan 2017
Climatology of thermospheric neutral winds over Oukaïmeden Observatory in Morocco
Mohamed Kaab1, Zouhair Benkhaldoun1, Daniel J. Fisher2, Brian Harding2, Aziza Bounhir1, Jonathan J. Makela2, Amine Laghriyeb1, Khalifa Malki1, Ahmed Daassou1, and Mohamed Lazrek1 1Oukaimeden Observatory, Laboratoire de Physique des Hautes Energies et Astrophysique, FSSM, Cadi Ayyad University, Marrakech, Morocco
2Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
Abstract. In order to explore coupling between the thermosphere and ionosphere and to address the lack of data relating to thermospheric neutral winds and temperatures over the African sector, a new system of instruments was installed at the Oukaïmeden Observatory located in the high Atlas Mountains, 75 km south of Marrakesh, Morocco (31.206° N, 7.866° W, 22.84° N magnetic). In this work we present the first multi-year results of the climatology of meridional and zonal winds obtained during the period from January 2014 to February 2016, including observations from 648 nights. The measurements are obtained using an imaging Fabry–Pérot interferometer, which measures the 630.0 nm emissions caused by dissociative recombination of O2+. The basic climatology of the winds is as expected, showing zonal winds that are strongly eastward in the early evening just after sunset with a speed of 50 to 100 m s−1 decreasing in magnitude, and reversing directions in the local summer months, towards sunrise. The meridional winds are slightly poleward in the early evening during the local winter, before reversing directions around 21:00 LT. In the local summer months, the meridional winds are equatorward for the entire night, reaching a maximum equatorward speed of 75 m s−1. We compare the observed climatologies of neutral winds to that provided by the recently updated Horizontal Wind Model (HWM14) in order to validate that model's predictions of the thermospheric wind patterns over the eastern portion of Africa. The model captures much of the features in the observational climatologies. The most notable exception is for the zonal winds during local summer, when the maximum eastward wind in the observations occurs approximately 4 h later than seen in the model results.

Citation: Kaab, M., Benkhaldoun, Z., Fisher, D. J., Harding, B., Bounhir, A., Makela, J. J., Laghriyeb, A., Malki, K., Daassou, A., and Lazrek, M.: Climatology of thermospheric neutral winds over Oukaïmeden Observatory in Morocco, Ann. Geophys., 35, 161-170, https://doi.org/10.5194/angeo-35-161-2017, 2017.
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Short summary
we present the first multi-year results of the climatology of horizontal winds obtained during a period of 26 months. We compare the observed climatologies of neutral winds to that provided by the recently updated Horizontal Wind Model (HWM14) in order to validate that model's predictions of the thermospheric wind patterns over the eastern portion of Africa. HWM14 generally compares well with the horizontal winds, but significant magnitude and phase differences remain in certain seasons.
we present the first multi-year results of the climatology of horizontal winds obtained during a...
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