Sources of salt Intrusion in a salt wedge estuary under extreme drought conditions

Salt intrusion is a major problem in deltas globally. Under climate change it is predicted to become a more serious issue. Understanding the source conditions of the saline water entering the estuary is of vital importance. Here we present data from a field campaign carried out around  the mouth of the Port of Rotterdam, during the major drought of 2022.  Mooring data (velocity, salinity and temperature) deployed around the mouth of the estuary are presented. We explore the changes in the near field plume dynamics during the drought and their connection to the inflowing waters at depth.  Our results suggest where the saltier inflowing waters to the estuary are sourced from offshore. We explore how and where mixing of plume waters takes place in the river plume  and its impact on lower-layer salinity variation in the nearfield.