Scientific Papers Series Management, Economic Engineering In Agriculture And Rural Development Vol. 17, Issue 3

 Journal

 Assessing Relationship Between Selected Climate Variables, Human Diseases And Drop Production Using ARDL Approach–The Example Of Ondo State, Nigeria

 Adewale Isaac Olutumise, Emmanuel Chilekwu Okogbue, Akinyemi Gabriel Omonijo

 2017

This study was designed to investigate the relationship between crop production and selected climatic variables and human diseases in Ondo State, Nigeria. Time series data spanning 32 years (1982 to 2013) were used for this study. The analytical tools employed for this study were descriptive statistics and auto-regressive distributed lag (ARDL) model. The results confirmed the presence of long run equilibrium between crop production and temperature, rainfall, incidence of malaria and incidence of pneumonia. The results of long run estimates showed that rainfall and pneumonia coefficients were significant but negatively affected crop production in the long run, while all the variable except temperature were also significant but negatively affected crop production in the short run. The error correction model (ECM) value of-0.142 which was significant at 5% level showed that about 14% of disequilibria from the previous year’s shock converge to the long run equilibrium in the current year. Therefore, disease prevention and environmental sanitation under the framework of the primary health care programme that can reduce human exposure to climate–related health risks should be strengthened by the government. 

 Modeling Earth Systems And Environment

 Journal

 Evaluation Of Wind Potential And Its Trends In The Mid-Atlantic

 Adekunle Ayodotun OsinowoEmail AuthorEmmanuel Chilekwu OkogbueEmmanuel Olaoluwa EresanyaOlumide Samuel Akande

 2011

This work utilized a 37-year (1980–2016) 10 m wind field dataset got from the European Center for Medium Range Weather Forecast (ECMWF) to examine the wind energy potential in the mid-Atlantic by using the Weibull parameters. The region generally showed a fairly good wind characteristics. The computed annual average wind power (170.23 w/m2) attributes the region as fairly suitable for wind power applications. Furthermore, locations such as State of Ceara and Sao Vicente in the southern and northern mid-Atlantic exhibits higher wind power of approximately 330 w/m2 and are therefore suitable for grid connected wind power applications. In all years and seasons, increasing positive trends in wind power density dominate waters between States of Ceara and Amapa in the southern mid-Atlantic. The wind power density showed an increasing trend of 0.13 w/m2/year in the mid-Atlantic throughout the study period. The trend inclined (1.1 w/m2/year) in winter and declined (??0.51 w/m2/year) during summer. 

 Meteorologische Zeitschrift  E. Schweizerbart'sche Verlagsbuchhandlung DOI: https://doi.org/10.1127/0941-2948/2002/0011-0419

 Journal

 Characterization Of Sky Conditions Over Ile-Ife, Nigeria, Based On 1992–1998 Solar Radiation Observations

 Emmanuel Chilekwu Okogbue, Joseph Adesola Adedokun

 2011

The aim of this study was to examine the temporal and spatial total column ozone distribution in West Africa using Total Ozone Mapping spectrometer (TOMS) daily data for five years between 2001 and 2005 in fifteen locations. In this study, certain significant observations emerged: weather activity particularly the rainfall producing mechanism (dynamic of the wind systems) was responsible for about 62% ozone distribution in the region. Ozone maximum and minimum concentrations over all the stations were 305 DU and 232 DU respectively producing an average range of 73 DU (only about 27.03% of the mean value). Ozone has a seasonal distribution with minimum occurring during the dry season and maximum occurring during the wet season. A decreasing rate of about –0.6 DU/year was found for the region. Interannual ozone characteristics revealed an oscillating feature similar to Quasi – biennial Oscillation (QBO) footprintswhich indicated the importance ofstratosphere – troposphere exchange to ozone distribution in the region. Furthermore, lag of about one or two months occurs between south (lower latitude) and north (higher latitude) monthly ozone maximums. 

 Royal Society Open Science 4 (11), 171120, 2017

 Journal

 Remote Sensing Appraisal Of Lake Chad Shrinkage Connotes Severe Impacts On Green Economics And Socio-economics Of The Catchment Area

 Olapeju Y Onamuti, Emmanuel C Okogbue, Israel R Orimoloye

 2011

Lake Chad commonly serves as a major hub of fertile economic activities for the border communities and contributes immensely to the national growth of all the countries that form its boundaries. However, incessant and multi-decadal drying via climate change pose greater threats to this transnational water resource, and adverse effects on ecological sustainability and socio-economic status of the catchment area. Therefore, this study assessed the extent of shrinkage of Lake Chad using remote sensing. Landsat imageries of the lake and its surroundings between 1987 and 2005 were retrieved from Global Land Cover Facility website and analysed using Integrated Land and Water Information System version 3.3 (ILWIS 3.3). Supervised classification of area around the lake was performed into various land use/land cover classes, and the shrunk part of its environs was assessed based on the land cover changes. The shrinkage trend within the study period was also analysed. The lake water size reduced from 1339.018 to 130.686?km2 (4.08–3.39%) in 1987–2005. The supervised classification of the Landsat imageries revealed an increase in portion of the lake covered by bare ground and sandy soil within the reference years (13?490.8–17?503.10?km2) with 4.98% total range of increase. The lake portion intersected with vegetated ground and soil also reduced within the period (11?046.44–10?078.82?km2) with 5.40% (967.62?km2) total decrease. The shrunk part of the lake covered singly with vegetation increased by 2.74% from 1987 to 2005. The shrunk part of the lake reduced to sand and turbid water showed 5.62% total decrease from 1987 to 2005 and a total decrease of 1805.942?km2 in area. The study disclosed an appalling rate of shrinkage and damaging influences on the hydrologic potential, eco-sustainability and socio-economics of the drainage area as revealed using ILWIS 3.3. 

 Theoretical And Applied Climatology 137 (1-2) By Springer-Verlag GmbH Austria

 Journal

 State-of-the-art Climate Modeling Of Extreme Precipitation Over Africa: Analysis Of CORDEX Added-value Over CMIP5

 Peter Gibba, Mouhamadou Bamba Sylla, Emmanuel Chilekwu Okogbue, Amadou Thierno Gaye, Michel Nikiema, Ibourahima Kebe

 2010

The ability of the state-of-the-art Global and Regional Climate Models (GCMs and RCMs) to reproduce the mean and spatial characteristics of extreme precipitation indices over Africa is evaluated. In particular, the extent to which CORDEX (COordinated Regional Downscaling Experiment) adds useful details on the performance of CMIP5 (Coupled Model Intercomparison Project Phase 5) multimodel ensemble is investigated. Comparison of the present day simulation was performed with two precipitation observation datasets, the high-resolution TRMM (Tropical Rainfall Measuring Mission) and coarse resolution GPCP (Global Precipitation Climatology Project), to evaluate models strengths and weaknesses. Eight indices generated from absolute (1 mm) and percentile (95th) based thresholds as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) are computed for seventeen CMIP5 GCMs and six CORDEX RCMs (for twelve downscaling experiments) for each year during the historical period (1975–2004). Our results suggest a good consistency between GPCP and TRMM in producing annual mean and frequency of extreme precipitation events over Africa despite few inconsistencies. However, their associated intensities largely differed from one another with GPCP data displaying drier bias. Overall, multimodel ensembles simulations overestimate the frequency of extreme precipitation events and underestimate their intensities. The results further show that CMIP5 exhibits wet bias of precipitation events and drier bias of precipitation intensity than CORDEX, and that CORDEX produces precipitation magnitude within the range of the observations and more in line with the higher-resolution TRMM data. This illustrates the added value achieved with the higher-resolution CORDEX multimodel ensemble for the simulation of such events, and points toward the use of these RCMs to study extreme precipitation for a better assessment of climate change over Africa. 

 Atmospheric And Climate Sciences By Scientific Research

 Journal

 Trend Analysis Of Drought In The Guinea And Sudano-Sahelian Climatic Zones Of Northern Nigeria (1907-2006)

 Temidayo O Omonijo, Emmanuel C Okogbue

 2010

A quantitative assessment of drought characteristics and their associated variability in the Northern Nigeria was carried out. Monthly rainfall data for all the selected locations which span a period of 100 years (1907-2006) collected from the Climate Research Unit (CRU) database were used. The resolution of the data is 0.5× 0.5 degrees in longitude and latitude. The long-term rainfall records were analyzed for drought using standardized precipitation index (SPI). The 100 years of Study was subdivided into 10 decades. Using Ilwis GIS software, the SPI results were presented on a spatial digitized map of northern Nigeria. This was done using the coordinates got from the Nigerian Meteorological Agency, Lagos Nigeria. The results of SPI analysis revealed that there were several drought years in the study period. Analysis further revealed that decade 7 to decade 9 (ie 1967-1976, 1977-1986, 1987-1996) witnessed persistent drought in the northern Nigeria. These were classified into mild, moderate, severe and extreme drought conditions. Near normal dry or mild drought was predominant in the 100 years of study. Mild drought has the highest number of occurrence in the northern Nigeria. A closer examination shows that north eastern part of Nigeria is susceptible to moderate drought. SPI analysis for 1, 3, 6 and 12 months was carried out. According to the Nigerian Meteorological Agency Classification, 1 month represents meteorological drought, 3 months represents agricultural drought, 6 months represents hydrological drought and 12 months represents socio-economic drought. The SPI analysis revealed distinct period of negative and positive values in which negative values indicate occurrence of drought and positive values imply there is no drought. This study has provided useful information and pro-active intervention to reduce the impact of drought which will be helpful to effectively plan rain-fed agriculture in northern Nigeria. 

 Atmospheric And Climate Science - Scientific Research Publishing Inc.

 Journal

 Trends In Vegetation Response To Drought In Sudano-Sahelian Part Of Northern Nigeria

 Blessing Bolarinwa Fabeku, Emmanuel C Okogbue

 2009

This study was carried out to evaluate the drought occurrence and its implication on vegetation cover over the Sudano-Sahelian zone of the Northern part of Nigeria. Monthly mean Rainfall data for the period 40 years (1971-2010) were obtained from Nigeria Meteorological Agency (NIMET) for each of the meteorological stations present and functioning in this region for climatic analysis. Standardized Precipitation Index (SPI) was used to analyze drought occurrence on a time scale of five (5) months that cover the period of raining season over the study area. Also Satellite data over the selected part of the study area for three different epochs, 1986, 2000 and 2005 were used for vegetation response analysis. The SPI values were interpolated using Inverse Distance Weighted (IDW) interpolation technique in ArcGIS 9.3 to generate Drought Spatial Pattern Map for each selected modeled years. The vegetation response indicators used are land cover maps and Greenness Index (GI) maps. Land cover categories were classified into five levels: Dense Vegetation, less dense Vegetation, Settlement/built up, Bare Surface and Water body. The results based on the ground truth (rainfall) data show that many years of drought episode were experienced over the study area. On the other hand, the prime indicators (Land cover and GI maps) used in this study also depicts the changes that took place over the study area in response to this climatic anomaly (drought) and it could be noted that there was dramatic reduction in the occurrence towards the end of the last two decade, 1990-1999, which simply indicated improvement in rainfall even in 2000 and the later years 

 Journal Of Solar Energy

 Journal

 Analysis Of Global Solar Irradiance Over Climatic Zones In Nigeria For Solar Energy Applications

 Adekunle Ayodotun Osinowo,1 Emmanuel Chilekwu Okogbue,2 Stephen Bunmi Ogungbenro,2 And Olugbenga Fashanu3

 2006

Satellite derived solar irradiance over 25 locations in the 5 climatic zones of Nigeria (tropical rainforest TRF, Guinea savannah GS, Sahel savannah SHS, Sudan savannah SUS, and Mangrove swamp forest MSF) was analyzed. To justify its use, the satellite data was tested for goodness of agreement with ground measured solar radiation data using 26-year mean monthly and daily data over 16 locations in the 5 climatic zones. The well-known R2, RMSE, MBE, and MPE statistical tests were used and good agreement was found. The 25 locations were grouped into the 5 climatic zones. Frequency distribution of global solar irradiance was done for each of the climatic zones. This showed that 46.88%, and 40.6% of the number of days (9794) over TRF and MSF, respectively, had irradiation within the range of 15.01–20.01?MJ/m2/day. For the GS, SHS, and SUS, 46.19%, 55.84% and 58.53% of the days had total irradiation within the range of 20.01–25.01?MJ/m2/day, respectively. Generally, in all the climatic zones, coefficients of variation of solar radiation were high and mean values were low in July and August. Contour maps showed that high and low values of global solar irradiance and clearness index were observed in the Northern and Southern locations of Nigeria, respectively. 

 International Journal Of Innovation Education And Research (IJIER) I

 Journal

 Correlation Of Global Solar Irradiance With Some Meteorological Parameters And Validation Of Some Existing Solar Radiation Models With Measured Data Over Selected Climatic Zones In Nigeria.

 Adekunle Ayodotun Osinowo And Emmanuel Chilekwu Okogbue

 2004

Fourteen models comprising of 12 existing and 2 parameterized models are evaluated for predicting the global solar irradiance on a horizontal surface at six different sites representative of six different climatic zones of Nigeria namely; Mangrove swamp forest (Calabar), Sahel Savannah (Nguru), Montane Vegetation (Yola), Sudan Savannah (Kano), Tropical rain forest (Ibadan) and Guinea Savannah (Minna). Results showed that the two models from this study performed well in predicting global solar irradiance over the six different zones with slight overestimation in some cases and slight underestimation in others. However, out of the two models, model 14 had a better predictive ability. For the 12 existing models, Glover and mcCulloch model was found to be most suitable for the Mangrove swamp forest, Sahel and Montane zones while Raja and Twidell , Rietveld and Annandale et al models are respectively the most suitable models in the Sudan, Tropical rainforest and Guinea zones. 

 Atmospheric Pollution Research

 Journal

 Analysis Of Temporal And Spatial Variability Of Total Column Ozone Over West Africa Using Daily TOMS Measurements

 Ayodeji Oluleye And Emmanuel Chilekwu Okogbue

 2003

The aim of this study was to examine the temporal and spatial total column ozone distribution in West Africa using Total Ozone Mapping spectrometer (TOMS) daily data for five years between 2001 and 2005 in fifteen locations. In this study, certain significant observations emerged: weather activity particularly the rainfall producing mechanism (dynamic of the wind systems) was responsible for about 62% ozone distribution in the region. Ozone maximum and minimum concentrations over all the stations were 305 DU and 232 DU respectively producing an average range of 73 DU (only about 27.03% of the mean value). Ozone has a seasonal distribution with minimum occurring during the dry season and maximum occurring during the wet season. A decreasing rate of about –0.6 DU/year was found for the region. Interannual ozone characteristics revealed an oscillating feature similar to Quasi – biennial Oscillation (QBO) footprints which indicated the importance of stratosphere – troposphere exchange to ozone distribution in the region. Furthermore, lag of about one or two months occurs between south (lower latitude) and north (higher latitude) monthly ozone maximums.