Severe Cold Harmattan Events in the Northwestern Region of Nigeria from 1961 to 2020

Abstract

This study examined the occurrences of severe cold harmattan events in Northwestern Nigeria from 1961 to 2020. Monthly minimum temperatures of the harmattan seasons (November to February) for five (5) selected stations: Kaduna, Kano, Gusau, Katsina, and Sokoto, were collected and analyzed over 60 years. A modified Standard Anomaly Index (SAI) was applied to determine the severe cold harmattan (SCH) events for the harmattan seasons. Findings revealed that SCH events occurred 55 times in the study area throughout the study period. In terms of geographical distribution, Sokoto experienced the most frequent SCH events (16 times in 60 years), followed by Kano and Katsina (15 times each). Kaduna had the lowest frequency (3 times), next to Gusau (6 times). Among decades, the second decade (1971-1980) had the highest occurrences of SCH in the study area (15 times in 10 years or 27.27%). Sokoto experienced the highest occurrence in this decade, while both Kaduna and Gusau witnessed the lowest. In regards to total decadal frequency, the most recent decade (2011-2020) and the first decade (1961-1970) tied for second. In general, all stations experienced SCH in the most recent decade (2011-2020). The study suggests that measures should be put in place to mitigate against SCH events that focus on climate change abatement strategies such as conventional mitigation, reduction of negative emissions, and unpleasant land use practices because climate change can increase the frequency of SCH and may put human health at risk of cold-related illnesses.