Assessing precipitation trends in the Americas with historical data: A review

North, Central, and South America (collectively referred to as the Americas) extend across two hemispheres, and together cover approximately 28% of Earth's land area and are home to about 13% of the world's population. Unique ecosystems, diversified cultures, and communities that inhabit the region rely on precipitation delivered yearly by multiple systems, including mid-latitudes storms, the North and South American Monsoons, and tropical storms and hurricanes. The rapid warming of the Earth's atmosphere and oceans combined with internal variability of the climate system, have modified precipitation patterns from the tropics to high latitudes. In the Americas, instrumental records have shown evidence of upward trends in extreme precipitation (amount, intensity, and frequency) in many areas. The most consistent evidence of precipitation trends occurs in mid-latitudes of North America and in the subtropics of South America. Recent studies have indicated a poleward shift of heavy precipitation associated with South American Monsoon. Nonetheless, the deficient network of rain gauges in vast areas over tropical Americas limits the assessment of trends in regions with heavy rainfall amounts. Additionally, observed trends in the North America monsoon precipitation are difficult to separate from the contribution of tropical storms and hurricanes. Furthermore, coupled modes such as the El Nino/Southern Oscillation, the Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation modulate precipitation in the Americas, from the tropics to the extratropics, and these teleconnections are relevant to assess precipitation trends using historical records. This review evaluates all these complex issues focusing on observations based on instrumental datasets. This article is categorized under: Paleoclimates and Current Trends > Modern Climate Change