Estimation of integrated water vapor derived from Global Navigation Satellite System observations over Central-Western Argentina (2015-2018). Validation and usefulness for the understanding of regional precipitation events

摘要

This study assesses the possibility of using Global Navigation Satellite System (GNSS) observations in combination with measurements of surface pressure and temperature to derive Integrated Water Vapor (IWVGNSS) estimates in Central-Western Argentina (CWA), a semi-arid region with complex topography. A significant agreement (coefficient of determination > 0.9) is observed between IWVGNSS and IWV estimates from radiosonde measurements, highlighting the capability of the GNSS stations to provide IWVGNSS estimates for a denser network. The variability of the IWV estimates, the atmospheric pressure and precipitation totals for a case study are compared. The results show that the occurrence of the increase in IWV values (positive IWV anomalies) precedes abundant precipitation over the CWA, in conjunction with the presence of mid-troposphere low-pressure anomalies acting as synoptic forcing. This kind of information provides a more comprehensive picture about the atmospheric processes involved in the development of deep convection, and it can be used for the development of contingency plans in the region. Heavy precipitation events and the difference in timing between positive IWV anomalies, both on-site and for their surroundings, should be considered.