Assessing temperature and water vapor in the atmospheric column over South America: a synopsis of identified trends using ERA5 reanalysis

Abstract

Climate change is already a reality globally. Several studies have quantified how these alterations affect specific energy budget components, such as radiative fluxes, heat storage, and energy transfer processes, correlating with verified modifications in several climate variables. Given the crucial role of thermodynamic processes in the hydrological cycle, this paper aims to provide a comprehensive overview of the climatology of air temperature and water vapor throughout the atmospheric column across South America. Moreover, detected trends in these variables are analyzed in the present climate using reanalysis data, focusing on the regions defined by the IPCC's Sixth Assessment Report (AR6). The results reveal an increasing air temperature trend at all levels of the atmosphere over the continent. The highest rates of air temperature rise are in the central portion of South America, while at high levels, the rate of warming is more significant in the northern part of the continent. There is an increasing trend in water vapor throughout the atmospheric column, particularly in the northern sector of South America. The identified decreasing trends of water vapor or specific humidity in the southeastern region do not exhibit a statistically significant signal. Such observed changes cause alterations in global and regional circulation patterns, mainly associated with extreme events.