TY - JOUR
T1 - Climatology of thermospheric neutral winds over Oukaïmeden Observatory in Morocco
AU - Kaab, Mohamed
AU - Benkhaldoun, Zouhair
AU - Fisher, Daniel J.
AU - Harding, Brian
AU - Bounhir, Aziza
AU - Makela, Jonathan J.
AU - Laghriyeb, Amine
AU - Malki, Khalifa
AU - Daassou, Ahmed
AU - Lazrek, Mohamed
N1 - Funding Information:
Work at the University of Illinois, including for the deployment of the instrumentation to Morocco, was supported by National Science Foundation CEDAR grants AGS 11-38998 and AGS 14-52291 as well as by NASA grant NNX14AD46G.
Publisher Copyright:
© Author(s) 2017.
PY - 2017/1/30
Y1 - 2017/1/30
N2 - 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 O+2. 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 100ms-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 75ms-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.
AB - 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 O+2. 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 100ms-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 75ms-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.
KW - Ionosphere (ionosphere-atmosphere interactions; ionospheric irregularities)
KW - meteorology and atmospheric dynamics (climatology)
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U2 - 10.5194/angeo-35-161-2017
DO - 10.5194/angeo-35-161-2017
M3 - Article
AN - SCOPUS:85011036676
SN - 0992-7689
VL - 35
SP - 161
EP - 170
JO - Annales Geophysicae
JF - Annales Geophysicae
IS - 1
ER -