Magnitude and frequency of heat and cold waves in recent decades: the case of South America
- 1European Commission, Joint Research Centre (JRC), Institute for Environment and Sustainability (IES), Water Unit, Via E. Fermi 2749, 21027 Ispra, Italy
- 2European Commission, Joint Research Centre (JRC), Institute for the Protection and Security of the Citizen (IPSC), Financial and Economic Analysis Unit, Via E. Fermi 2749, 21027 Ispra, Italy
- 3Facultad de Ingeniería Ambiental, Universidad Santo Tomás, 5878797 Bogota, Colombia
Abstract. In recent decades there has been an increase in magnitude and occurrence of heat waves and a decrease of cold waves, both of which may be related to the anthropogenic influence. This study describes the extreme temperature regime of heat waves and cold waves across South America over recent years (1980–2014). Temperature records come from the Global Surface Summary of the Day (GSOD), a climatological data set produced by the National Climatic Data Center that provides records of daily maximum and minimum temperatures acquired worldwide. The magnitude of heat waves and cold waves for each GSOD station are quantified on an annual basis by means of the Heat Wave Magnitude Index and the Cold Wave Magnitude Index. Results indicate an increase in intensity and in frequency of heat waves, especially in the last 10 years. Conversely, no significant changes are detected for cold waves. In addition, the trend of the annual temperature range (i.e. yearly mean of Tmax – yearly mean of Tmin) is positive – up to 1 °C per decade – over the extratropics and negative – up to 0.5 °C per decade – over the tropics.