The complex Andes region needs improved efforts to face climate extremes

Abstract

The steep slopes, highlands, and valleys of the Andes mountain chain are inhabited throughout its formidable length. This unique characteristic does not repeat in any other mountain region. The Andes shape weather and climate in South America. However, proper understanding of atmospheric phenomena influenced by a daunting altitudinal gradient is still behind what is needed to produce detailed and consistent climate projections. Despite significant advances, global models misrepresent key precipitation and circulation processes that are influenced by complex topography. Along with a lack of coordinated observations, the result is limited information to design preparedness measures, particularly to face extreme climate events. Of equal concern is the issue of air quality in densely urbanized countries that face decarbonization challenges and share a legacy of social inequity and political unrest. The complexity of the Andes region magnifies risks within all nations that share their influence. Thus, urgent action is needed to improve climate and air quality assessments with the direct purpose of strengthening policy-making processes.

Performance of Regional Climate Model Precipitation Simulations Over the Terrain‐Complex Andes‐Amazon Transition Region

“…Nonetheless, there remains a pressing need for long-term and comprehensive precipitation monitoring on the eastern slopes of the Andean cordillera. The complex interactions between terrain and regional atmospheric circulation in this area give rise to a wide range of hydroclimatic regimes (Cazorla et al, 2022;Condom et al, 2020). For example, Newell et al (2022) demonstrated the importance of a network of rain gauges to capture the fine-scale spatiotemporal variability of rainfall in montane cloud forests in the northeastern Andes of Peru.…”

“…Nonetheless, there remains a pressing need for long‐term and comprehensive precipitation monitoring on the eastern slopes of the Andean cordillera. The complex interactions between terrain and regional atmospheric circulation in this area give rise to a wide range of hydroclimatic regimes (Cazorla et al., 2022; Condom et al., 2020). For example, Newell et al.…”

“…Therefore, the substantial diversity of rainfall regimes, stemming from the complex orographic features, renders regional climate modeling in the Andes‐Amazon transition region a particularly challenging endeavor. However, it is worth noting that these challenges are compounded with uncertainties associated with observational data, including both satellite and gauge‐based products, as well as the limited availability of observations in the Andes‐Amazon transition (Cazorla et al., 2022; Condom et al., 2020; Falco et al., 2019; Fassoni‐Andrade et al., 2021; Gibson et al., 2019).…”

Latitudinal and temporal distribution of aerosols and precipitable water vapor in the tropical Andes from AERONET, sounding, and MERRA-2 data

“…Understanding the current distribution of aerosols and precipitable water vapor (PW) over climate vulnerable regions such as the tropical Andes is critical given that atmospheric composition continues to change rapidly and globally. The tropical Andes mountains are densely populated, unlike other mountain regions in the world, a remarkable feature in addition to their high altitude and continental scale length 1 . Examples of large and medium-size Andean cities are Medellín, Bogotá, Cali, Quito, Cuenca, Huancayo, and La Paz, but numerous towns of varied sizes are distributed all along Andean valleys and highlands (Fig.…”

“…However, a more extensive coordinated investigation on the characteristics and origin of atmospheric aerosols and how they become distributed along the tropical Andes has been lacking. A dedicated look at PW in connection to rainfall is also necessary given that climate projections indicate that extreme precipitation events are expected to increase in the northwestern South American region, while more southern Andean latitudes are expected to suffer increased droughts 1 , 4 . Here, we present a consolidated study that delves into the status and changes in near surface and columnar aerosols and water vapor over the tropical Andes, which is relevant at a time of imminent climate change.…”