Study of Periodicity in Some Meteorological Parameters and Solar Indices Over Some Stations in Nigeria

Periodicities of the mean monthly values of some meteorological parameters and solar indices over some stations in Nigeria have been examined. We used maximum and minimum temperature, rainfall, relative humidity, evaporation, sunshine duration, solar radiation and windspeed data as climate parameters and sunspot numbers and F10.7cm radio solar flux data as solar activity indicators. The Ikeja, Ilorin and Maiduguri stations were chosen as case studies based on the geographical locations in Nigeria to cover various climatic region from the coastal region in the south to the arid region in the north. The Fourier analysis technique Scargle periodogram was used to study the spectral characteristics of the meteorological variables and solar indices for these three stations. 124months/cycle periodicity, in wind speed, was found for the Ikeja station corresponding to the 125months/cycle of solar activities, showing the influence of solar activities on climate. It was established that solar forcing was very significant over Nigerian climate. Keywords: periodicity, solar activity, Sun-climate relation

SEASONAL VARIABILITY OF SOME METEOROLOGICAL PARAMETERS WITH RESPECT TO SOLAR ACTIVITY OVER SOME STATIONS IN NIGERIA

In this study, we investigated the effects of solar activity on periodic variability of some meteorological parameters for three meteorological stations in Nigeria, from 1980 to 2010. Maximum and minimum temperature, rainfall, relative humidity, evaporation, sunshine duration, solar radiation and windspeed data were used as climate parameters and sunspot numbers data as solar activity indicator. Time series plots of the climatic/meteorological parameters and sunspot numbers were made for each station in order to observe their trend of variations with respect to solar activity effects on the various climatic parameters. The correlation coefficients between the various meteorological variables and solar indices at each station were obtained and given for the considered locations. Results obtained showed that above 95% level of statistically significantcorrelations exist between sunspot numbers and some climatic parameters for all the locations considered

Entanglement fidelity for electron-electron interaction in strongly coupled semiclassical plasma and under external fields

This paper presents the effects of AB-flux field and electric field on electron-electron interaction, encircled by a strongly coupled semiclassical plasma. We found that weak external fields are required to perpetuate a low-energy elastic electron-electron interaction in a strongly coupled semiclassical plasma. The entanglement fidelity in the interaction process has been examined. We have used partial wave analysis to derive the entanglement fidelity. We found that for a weak electric field, the fidelity ratio for electron-electron interaction increase as projectile energy increase but remains constant or almost zero for a strong electric field. Our results provide an invaluable information on how the efficiency of entanglement fidelity for a low-energy elastic electron-electron interaction in a strongly coupled semiclassical plasma can be influenced by the presence of external fields

Temperature Performance Evaluation of Parabolic Dishes Covered with Different Materials in Iwo, Nigeria

Solar radiation reaching the earth is considered to be affected by some parameters like diffusion. This radiation is reflected or scattered by air molecules, cloud and aerosols (dust). Parabolic dishes made of different materials (glass, foil and painted surface) were used to concentrate energy on a copper calorimeter filled with water. A thermometer was inserted in each of the copper calorimeter placed at the focus of the dishes. The experiment was performed from March to April (a period of five weeks), from 9:00am to 5:00pm daily with readings obtained at intervals of 30 minutes every day for one week and was later changed to hourly readings for the remaining four weeks. The initial and final temperatures of the water were determined. The parabolic dish with glass material gave the highest temperature of 56.9oC followed by foil with an average temperature of 48.7oC and painted silver colour with an average temperature of 45.1oC for the daily variation. For the other weeks, the average temperature of the dish with glass was 57.6oC  for foil, 46.9oC and painted silver colour, 40.8oC. The parabolic dish with glass is able to generate a higher temperature compared with foil and painted silver colour. Keywords: Glass, Foil, Silver Colour and Parabolic Dish

SPACIO-TEMPORAL VARIATION OF RADIO REFRACTIVITY IN LAFIA, NASARAWA STATE USING CM SAF ATOVS SATELLITE DATA

Communications using radio waves propagates through the atmosphere and plays a major role in civilization. Vertical variation of radio refractivity in Lafia( 8.492°N and 8.517°E ) Nigeria, was investigated with a five-year (2010 – 2014) monthly mean atmospheric layered data from the ATOVS (Advanced TIROS (Television InfraRed Observation Satellite) Operational Vertical Sounders) instruments flying onboard the NOAA and Metop-A satellites; this data is provided by the EUMETSAT’s Climate Monitoring Satellite Application Facilities (CM SAF). Using the CM SAF data, at six pressure levels (1000hPa, 850hPa, 700hPa, 500hPa, 300hPa and 200hPa), the monthly mean of radio refractivity were estimated and the results analyzed. Also, the diurnal variation of the surface radio refractivity was also investigated using the data from the automatic weather station (model no WS104) installed at the Department of Physics, Federal University Lafia. Results obtained showed that the vertical model of the radio refractivity N, in Lafia could be given as N=No exp(-h⁄ho ),where No, the surface radio refractivity, was found to be approximately equal to 288.1 N-units, while the scale height ho, was found to be approximately equal to 8.40km; it was found that sub-refraction predominates in Lafia at all seasons. The diurnal range of surface radio refractivity as measured by the in-situ weather station was found to be between 325.0 and 365.0 N-units, with a maximum in the morning and minimum in the afternoo