Rain stable water isotope data from the city of Arequipa, Peru during 2019 wet season

<p>This data repository accompanies the publication "<b>Reinterpreting the Stable Water Isotope Signatures in Precipitation in the Andean Western Cordillera Due to Sub-seasonal Moisture Source Changes and Sub-cloud Evaporation"</b>.</p>

<p>The extremely arid western Andean rain shadow receives approximately 100 mm of precipitation typically transported by strong easterly winds at high altitudes from the Amazon basin over the Andes. Here, we examined daily rain amounts and oxygen and hydrogen isotopic ratios from a network of collectors in the southern Peruvian city of Arequipa at 2,300 meters elevation on the western flank of the Andes during the 2019 summer monsoon season (January – March). The isotopic signature of dominant easterly moisture transport was surprising enriched in heavy isotopes due to strong sub-cloud evaporation. Previously, enriched isotopic signatures have been interpreted as Pacific moisture influence. Shifting meteorologic conditions transported isotopically depleted northerly moisture into the area for two weeks including two days of intense rainfall, flooding, and landslides in several communities. Large-scale moisture transport in past climates may be studied through preserved isotopic proxies with this refined knowledge of isotopic signature controls.</p>