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Anthropogenic global warming might cause expansion of the drylands and trigger socio‐economic challenges in the water‐deficit subtropical regions. Changes in hydroclimate during the intervals of variable global temperature over the recent geological past, however, could provide useful information about the possible responses of these arid ecosystems to the near future warmer conditions. We evaluated hydroclimates of two different parts of subtropical North America by generating new records of surface processes and regional vegetation from drought‐prone northeast Mexico and subsequently compared them with the paleoclimate of the central‐southern United States. Our study suggests that congruent changes occurred in both parts during ~13.5–9.5 cal ka BP, an interval with no warm pool in the northern Gulf of Mexico. The precipitation and erosion responded to temperature‐modulated variations in positions of the Inter‐Tropical Convergence Zone (ITCZ). Conditions were wetter than today in the subsequent warmer interval (~9.5–8.2 cal ka BP) with generally stable ITCZ and the highest summer insolation. Hydroclimate changes of both parts lacked congruency during ~8.2–6.8 cal ka BP as the northern Gulf of Mexico began hosting a warm pool. Similar to the modern conditions, this warm pool might have modified trajectories of the tropical storms. Erosion and abundance of C3 plants decreased in northeast Mexico. Higher wetness in the Mississippi River Basin and the southern Great Plains during this interval suggested that the storms made landfall more frequently in the central‐southern United States. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• Hydrogeochemical evolution in semi-arid region. • Identification of recharge areas in Sierra Madre Oriental and moisture sources. • Warm season recharge in northeast Mexico and global warming. • Further depletion of groundwater resources and agricultural productivity. Over exploitation for agricultural activities and consumption has depleted the groundwater resources of drought-prone northeast Mexico. Major ion concentrations along with δ18O H2O , δ2H H2O and d-excess values of shallow groundwater from the Cieneguilla Basin (near Tula) located at a distance of ∼200 km from coast of the Gulf of Mexico helped to contribute new data about drought vulnerability in this region through identification of the moisture source and groundwater recharge zone. Different degrees of rock-water interaction through gypsum, anhydrite and halite dissolutions and minor silicate weathering controlled the hydrochemistry. Stable isotopes yielded a least square regression and slope similar to the local as well as global meteoric water lines, indicating minimal effect of evaporation during the recharge as well as in the subsoil. Isotopic fractionations along with a digital elevation model demarcated the recharge zones at north and east of the basin, with altitudinal difference of ≥1000 m, and indicated that the recharge occurred through warm season moisture sourced from the Gulf of Mexico. Less frequent landfalling of tropical storms caused by warmer sea surface temperature, however, has reduced this rainfall over the last few decades. If the trend of global warming continues unabated, the depleted groundwater resources would trigger reduction in agricultural activities in this drought-prone region and lead to enhanced socio-economic challenges. [ABSTRACT FROM AUTHOR]

An evaporite enriched sediment archive from the dry Sandia Basin located in the water-stressed western foothills of the Sierra Madre Oriental Mountains (northeast Mexico) was studied to reconstruct depositional histories of vegetation and rainfall intensity in orbital to millennial-scales over the last ~32.5 cal ka. Surrounding vegetation had more C 3 plants during the late last glacial and deglaciation and the expansion of more drought tolerant C 4 plants occurred only after ~5 cal ka BP. Clastic minerals were sourced from different lithologies within the watershed and their abundances helped to infer runoff dynamics and hence the rainfall intensities. Deposition of more mixed-layer clay represented wetter intervals over the late last glacial and deglaciation. Transportation of clastics from the nearby lithology during these wetter intervals suggested that high-intensity rainfall events were less frequent. Response to the Heinrich stadials (H3, H2 and early H1) was mainly similar (drier) and erosion in the watershed remained less-than-average. Transportation of more quartz-rich sediments from distal lithologies during the late Bølling-Allerød (B/A) interstadial and between ~6.2 and 4 cal ka BP with a depositional hiatus between ~12.7 and 6.2 cal ka BP represented the intervals of more frequent high-intensity rainfall events, possibly related to short-lived storms. We hypothesize that the Gulf of Mexico sea surface temperature was a principal forcing. Total annual precipitation in this region decreased but the frequency of short-lived storms increased during the warmer Atlantic Multidecadal Oscillation (AMO) states. Warmer conditions also led to deposition of more gypsum. Our observation, however, needs further evaluation under the modern-day greenhouse warming scenario. • Late Quaternary vegetation and rainfall records from semi-arid north-east Mexico. • Forcing of Atlantic Multidecadal Oscillation state on high intensity precipitation events. • Less frequent high-intensity rainfall events during cooler late last glacial. • More frequent short-lived storms since the B/A interstadial. • Expansion of drought tolerant C 4 plants after 5,000 cal years BP. [ABSTRACT FROM AUTHOR]