Climate change projections of temperature and precipitation in Chile based on statistical downscaling

Abstract

General circulation models (GCMs) allow the analysis of potential changes in the climate system under different emissions scenarios. However, their spatial resolution is too coarse to produce useful climate information for impact/adaptation assessments. This is especially relevant for regions with complex orography and coastlines, such as in Chile. Downscaling techniques attempt to reduce the gap between global and regional/local scales; for instance, statistical downscaling methods establish empirical relationships between large-scale predictors and local predictands. Here, statistical downscaling was employed to generate climate change projections of daily maximum/minimum temperatures and precipitation in more than 400 locations in Chile using the analog method, which identifies the most similar or analog day based on similarities of largescale patterns from a pool of historical records. A cross-validation framework was applied using different sets of potential predictors from the NCEP/NCAR reanalysis following the perfect prognosis approach. The best-performing set was used to downscale six different CMIP5 GCMs (forced by three representative concentration pathways, RCPs). As a result, minimum and maximum temperatures are projected to increase in the entire Chilean territory throughout all seasons. Specifically, the minimum (maximum) temperature is projected to increase by more than 2 °C (6 °C) under the RCP8.5 scenario in the austral winter by the end of the twenty-first century. Precipitation changes exhibit a larger spatial variability. By the end of the twenty-first century, a winter precipitation decrease exceeding 40% is projected under RCP8.5 in the central-southern zone, while an increase of over 60% is projected in the northern Andes.

Assessment of the Future Impact of Climate Change on the Hydrology of the Mangoky River, Madagascar Using ANN and SWAT

“…However, a decrease in minimum temperature is projected in summer in the 2040s. This decrease in minimum temperature suggests a cooling from the surface water near the coast, neutralizing the warming effect [55]. The highest increase in seasonal minimum temperature is projected under SSP5-8.5 in the 2090s, with an increase of about 4.2 • C. Consistent with previous studies, we found that seasonal and annual temperatures in Africa are expected to increase rapidly than the global average in the 21st century [5].…”

Water Resources Change in Central-Western Argentina Under the Paris Agreement Warming Targets

“…Next steps will consider the use of both downscaled General Circulation Models and hydrological models to provide critical information at the basin scale considering the complex topography of the Andes mountains. This kind of studies has been recently developed in Brazil by Avila-Diaz et al (2020a,b), who provided information regarding the projected evolution of extreme precipitation and temperature indices, and in Chile by Araya-Osses et al (2020), who generated climate change projections of daily maximum and minimum temperature and precipitation in more than 400 locations. The outcomes of this future study will provide tailored information that can aid decision-making processes in near-term agricultural practices and water management.…”

Role of Integrated Approaches in Water Resources Management: Antofagasta Region, Chile

“…The region has a population of 402,669 as per the 2015 census. Antofagasta has an average annual temperature of 16.8 • C and July is the coldest month, with an average low temperature of 11.8 • C, and an average high temperature of 16.5 • C [1]. In Chile, the Antofagasta region is called the mining industry s heart, generating 53% of the mining output, led by copper and followed by potassium nitrate, gold, iodine, and lithium in the area.…”

“…Chile has a boundary with Peru in the north, Bolivia in the northeast, Argentina in east, and the Pacific Ocean in the west. Chile is divided into 16 regions and has a diverse climate, such as northern region belongs to world s driest desert with a semi-arid climate, the center region of the country belongs to a Mediterranean climate, Easter Island has humid subtropical climate and east and south regions including alpine tundra and glaciers are belong to oceanic climate [1]. Chile has four significant seasons, summer from January to March, autumn during the April to June, winter during the July to September, and spring during the October to December.…”