This paper examines the temporal variability of aridity in Argentina during the period 1961–2020. Monthly data from the Climatic Research Unit (CRU) were used to define climate types according to the Aridity Index (AI) from the United Nations Environment Programme (UNEP). Argentina presents a variety of climates ranging from arid and semiarid to subhumid and humid, suggesting simultaneous water deficit and excess conditions. However, an aridity increase in the past six decades has been observed in much of the country, contrasting with reduced areas that have become wetter. Since these changes were not uniform across the study area, a regional-level analysis was conducted to adequately capture the aridity temporal patterns, including trends, jumps, seasonality, and cycles. In general, there was a decrease in the annual AI in most regions, with non-linear patterns such as long-term oscillations, shorter-duration cycles, and abrupt variations in the average. Seasonal aridity changes showed variabilities according to the season, with higher humidity during summer and autumn, and greater aridity during winter and spring. Simultaneously, seasonal AI experienced periodic behavior with significant arid and humid cycles alternating every 10–15 years. These findings highlight the complexity of climate changes, which vary by region and season.

中文翻译：

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1961-2020年阿根廷干旱度的时间变化


本文研究了 1961 年至 2020 年期间阿根廷干旱度的时间变化。气候研究单位 (CRU) 的每月数据用于根据联合国环境规划署 (UNEP) 的干旱指数 (AI) 定义气候类型。阿根廷呈现出从干旱和半干旱到半湿润和潮湿的多种气候，表明缺水和过剩条件同时存在。然而，在过去的六十年中，该国大部分地区的干旱程度有所增加，而变得更加湿润的地区则减少了。由于这些变化在整个研究区域并不统一，因此进行了区域级分析，以充分捕捉干旱时间模式，包括趋势、跳跃、季节性和周期。总体来看，大部分地区年度人工智能呈下降趋势，并呈现长期振荡、较短周期、平均值突变等非线性模式。季节干旱变化呈现季节差异，夏、秋季湿度较高，冬、春季干旱程度较大。同时，季节性人工智能经历了周期性行为，每 10-15 年就会出现明显的干旱和潮湿循环。这些发现凸显了气候变化的复杂性，气候变化因地区和季节而异。