Key points are not available for this paper at this time.
This study investigates the impact of a 40% Amazon deforestation scenario (projected for 2050) on precipitation over the central Peruvian Andes during five austral summer seasons (DJF 2001–2006) using high-resolution (1 km) WRF simulations. While a widespread rainfall reduction pattern is observed over the Amazon-Andes transition zone, statistically significant decreases ( p < 0.10) at the gridpoint level are primarily concentrated near rainfall hotspots in the Amazon-Andes transitions zone, reaching an average reduction of 12% (−1.4 mm day −1 ). This drying signal is physically associated with a weakening of the South American Low-Level Jet (LLJ) and reduced moisture influx, which specifically inhibits convective activity during the morning peak hours (23–11 LT). In the high-altitude Mantaro Basin, we observe a consistent drying pattern (−5%) that extends from the transition zone; although these changes are not statistically significant due to high interannual variability, the physical signal of precipitation reduction and dry air advection remains clear. Conversely, the western Andean ridges exhibit a localized precipitation increase (up to 20%) linked to intensified cross-barrier easterly wind anomalies reinforcing diurnal anabatic circulation. We further find that while 5 km resolution captures broad basin-scale patterns, convection-permitting scales (1 km) are essential for resolving these complex topographic effects. These findings highlight a critical vulnerability concentrated along the eastern slopes and the high Andes. The identified drying patterns, which are particularly pronounced in the Andes-Amazon transition zone (a global biodiversity hotspot) and extend into the highlands, pose a significant threat to endemic ecosystems and regional water security, specifically through reservoir inflow reduction and negative impacts on agriculture. • Amazon deforestation significantly reduces rainfall (~12%) in Andes-Amazon hotspots. • Drying signal extends to the strategic Mantaro Basin (−5%) and high Andes. • Intensified cross-barrier flow is linked to rainfall increases on western ridges. • Eastern and highland rainfall drop links to weakened LLJ and dry easterly advection. • Convection-permitting scale (1 km) is essential for resolving narrow valley effects.
Saavedra et al. (Wed,) studied this question.