Using the facilities at Heliophysics Science Division of NASA Goddard Space Flight Center, Greenbelt, MD, USA, we attempted to investigate the impact of solar magnetic activities on the climate of Wet Zone West Africa. The solar activity data namely, Sunspot Number (SSN) was obtained from the Royal Observatory of Belgium, Brussels; and Geomagnetic aa-index was obtained from World Data Center, Kyoto, Japan. Surface Air Temperature (SAT) and Rainfall data [for Port Harcourt in Nigeria and Abidjan in Cote D’Ivoire] were obtained from the HadCRUT-4 project of Climate Research Unit of University of East Anglia, United Kingdom. Firstly, we carried out Time Series Analysis of SSN and Geomagnetic aa-index spanning from 1950 to 2016. Secondly, we performed Regression Analysis on both solar activity data and climate variables to estimate the impact of solar magnetic activity on the Wet Zone West African climate. The Time Series Analysis showed that SSN variation was in-phase with Geomagnetic aa-index in all the solar cycles studied. Thus, Geomagnetic aa-index can be used as a proxy for studying solar magnetic activities. Performance of Regression Analysis showed that SSN regressed on SAT and Rainfall amounted to an average of 0.49 and 0.02% respectively throughout Solar Cycles 22–24. Furthermore, a regression of Geomagnetic aa-index on SAT and Rainfall yielded an average of 0.145 and 0.125% respectively. Our models showed that the variability of SAT and Rainfall in Wet Zone West Africa during Solar Cycles 22–24 are far less than 1%. Hence, the influence of SSN and Geomagnetic aa-index on SAT and Rainfall is less than 1%; and could cause ‘very small’ effect. These weak impacts are proofs that the variability of SAT and Rainfall were most probably not effected by SSN and Geomagnetic aa-index. Consequently, the variability of SAT and Rainfall in Wet Zone West Africa could not be attributed to SSN and Geomagnetic aa-index. We therefore, attempt to conclude that climate variability in Wet Zone West Africa is most probably not driven by solar magnetic activity, but could be attributed to anthropogenic activities.

Abstract. In this work, we attempted to investigate the contributions and effects of coronal mass ejections (CMEs) on total electron content (TEC) in the ionosphere of an equatorial station, Nsukka (Lat. 6.86N; Long 7.38E) located in South Eastern Nigeria. Using TEC data recorded by the Global Positioning System (GPS) of the Air Force Research Laboratory, USA, and CME data obtained from the USA owned Solar and Heliospheric Observatory (SOHO) satellite, we calculated the variation of TEC in the solar maximum year 2012, and observed regular, Gaussian distribution of TEC during geomagnetic solar quiet (Sq) days. On days associated with CME events, TEC variations assumed very sporadic patterns; maximized quite early during geomagnetic disturbed days and peaked at later hours during quiet days. The ionospheric electron contents are generally very low at both pre-noon and nighttime hours but quite high at noon and post-noon hours. This pattern of TEC variation is due to fluctuation in solar radiations incident on earth’s equatorial ionosphere. During quiet periods the number of free electrons generated is smaller in comparison to that generated during disturbed times, which shows a positive contribution of CMEs to TEC profile. TEC profiles for days categorized as neither disturbed nor quiet are synonymous to TEC curves on quiet days. There is significant time-variance in peak-time of TEC between disturbed and quiet days. TEC maximized quit earlier on disturbed days, implying increased influx of charged particles into the ionosphere due to the prevailing CME events. These results can contribute as input to the ionospheric monitoring and forecasting for the equatorial region of South Eastern Nigeria.

Galactic Cosmic Rays (GCRs) incidence on the Earth’s near space environment is of major concern to humankind as it affects space weather. Upon entering Earth’s atmosphere, GCRs collide with atoms and molecules, and subsequently decay into muons and neutrinos which propagates through the earth’s surface. Theory and observations affirm that penetration of GCR from the Heliospheric Magnetic Field (HMF) to Earth’s atmosphere is leveraged by the earth’s magnetic force lines predominant at the polar regions. We used facilities at NASA Goddard Space Flight Center, Greenbelt, Maryland USA and analyzed GCR particles recorded by Neutron Monitors (NM) at Thule, Newark, Mc Murdo and South Pole hosted at Bartol Research Institute, University of Delaware, USA. Geomagnetic aa index was obtained from World Data Center for Geomagnetism, Kyoto, Japan. This work investigates the degree to which GCRs are modulated by Geomagnetic activities using Geomagnetic aa-index as a proxy to Geomagnetic activity. We studied GCRs incident at four Neutron Monitor (NM) Stations at; Thule in the Arctic region, McMurdo and South Pole in the Antarctica, and Newark in the Middle Latitude region across five solar cycles timescale (1964 to 2016). We performed Regression Analysis of GCR and Geomagnetic aa-index to observe the impact of geomagnetic activity on GCR flux at the designated regions of the Earth’s surface. Also, we carried out Time Series Analysis to observe GCR intensities at the four NM Stations for the period of study. Results from Regression Analysis revealed a weak association between GCR and Geomagnetic aa index, where Coefficient of Determination R2 is less than 0.5. The Time Series Analysis revealed highest fluxes of GCR at Thule, McMurdo and South Pole as compared to incidence at the Mid-Latitude region in Newark. Our model indicate that GCR fluxes are controlled by Geomagnetic Field structure.