Atmospheric Groundwater Forcing of a Subterranean Estuary: A Seasonal Seawater Recirculation Process

Abstract

Here we isolate groundwater responses to atmospheric forcing of surface water levels by relating anomalies in coastal aquifer hydraulic head time-series to weather events. Our results demonstrate that atmospheric forcing has a greater effect on groundwater exchange and extended residence time over astronomical tidal pumping at times. During winter, atmospheric groundwater forcing was associated with winter storm passage and had a recurrence interval of approximately 7 days. During summer, atmospheric groundwater forcing was limited to weak diurnal atmospheric convection and infrequent tropical cyclone activity. Because winter storms and tropical cyclones commonly produce precipitation, atmospheric groundwater forcing can synergize with the timing of meteoric recharge producing periods of intense submarine groundwater discharge.