When There Are Atmospheric Data Gaps: What Can Researchers Do?

Ayanlade, A.  2015.  When There Are Atmospheric Data Gaps: What Can Researchers Do? In Gbadegesin, A. S., Eze E. B., Oluwagbenga O. O. I., & Fashae O. A. (2015). Frontiers in Environmental Research and Sustainable Environment in the 21st Century. : Ibadan University Press


This study aims at describing and evaluating the relevance of Geographical Information System (GIS) procedures as a standard technique to model atmospheric parameters when there are several data gaps. Generally, high resolution atmospheric parameters are needed to assess the impacts of climate change on crop productivity at the local level, using data at the level of individual farm units. Such high resolution climatic data are non-existent in the West African setting because of the extremely sparse meteorological station network. The problems often arise as to what values to attach to climatic variables at points other than these nodes where there are data gaps. Therefore, GIS interpolation and downscaling methods were used to assess how gaps in climatic parameters could be filled using Nigeria as a case study. Several GIS interpolation methods have been tested for the production of maps in this study. After many attempts of the qualitative and quantitative validations, the last of these- Ordinary Kriging- was chosen for the map productions. A major strength of the method is that measured spatial dependence in the weather parameter of interest and this is used to produce digital maps. Ordinary Kriging was used to interpolate the point observations from a network of rainfall base stations. The results from this study show that GIS interpolation are helpful for downscaling spatial dynamics of climate and also useful in forecasting probable period for farming activities.