Advancing Heat-as-a-Tracer Groundwater Flux Estimates in Preferential
Discharge Zones via Instrumentation and Methods
- Robert Sohn
, - Martin A Briggs
, - David Rey

Robert Sohn

Woods Hole Oceanographic Institution
Corresponding Author:rsohn@whoi.edu
Author ProfileMartin A Briggs

United States Geological Survey, Hydrogeophysics Branch
Author ProfileAbstract
Preferential groundwater discharge zones are critical to a wide range of
surface water habitat and water quality processes, but they can be
difficult to characterize due to strong spatial variability in flux rate
and high attenuation of natural temperature signals. As such, passive
heat-as-a-tracer methods employing Vertical Temperature Profiler data
are often ill-suited for quantifying vertical discharge flux rates due
to a combination of inadequate sensor distribution and resolution paired
with analytical modeling methods based on diurnal signals only. Using
data from a site of contaminant-loaded groundwater discharge to the
Quashnet River on Cape Cod, Massachusetts, USA, we demonstrate how
coupled improvements in instrumentation and parameter estimation methods
can largely alleviate these issues. Consequently, more accurate
groundwater flux estimates, including temporal variations, are now
possible at sites of strong discharge using passive heat-as-a-tracer
methods.17 Aug 2023Submitted to ESS Open Archive 21 Aug 2023Published in ESS Open Archive