Mulligan Ann E.

No Thumbnail Available
Last Name
Mulligan
First Name
Ann E.
ORCID

Filters

2009 - 2009 1 2010 - 2013 1
2
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Article
    A differential pressure instrument with wireless telemetry for in-situ measurement of fluid flow across sediment-water boundaries
    (Molecular Diversity Preservation International, 2009-01-09) Gardner, Alan T. ; Karam, Hanan N. ; Mulligan, Ann E. ; Harvey, Charles F. ; Hammar, Terence R. ; Hemond, Harold F.
    An instrument has been built to carry out continuous in-situ measurement of small differences in water pressure, conductivity and temperature, in natural surface water and groundwater systems. A low-cost data telemetry system provides data on shore in real time if desired. The immediate purpose of measurements by this device is to continuously infer fluxes of water across the sediment-water interface in a complex estuarine system; however, direct application to assessment of sediment-water fluxes in rivers, lakes, and other systems is also possible. Key objectives of the design include both low cost, and accuracy of the order of ±0.5 mm H2O in measured head difference between the instrument’s two pressure ports. These objectives have been met, although a revision to the design of one component was found to be necessary. Deployments of up to nine months, and wireless range in excess of 300 m have been demonstrated.
  • Article
    Climate-driven sea level anomalies modulate coastal groundwater dynamics and discharge
    (John Wiley & Sons, 2013-06-03) Gonneea, Meagan E. ; Mulligan, Ann E. ; Charette, Matthew A.
    To better understand the physical drivers of submarine groundwater discharge (SGD) in the coastal ocean, we conducted a detailed field and modeling study within an unconfined coastal aquifer system. We monitored the hydraulic gradient across the coastal aquifer and movement of the mixing zone over multiple years. At our study site, sea level dominated over groundwater head as the largest contributor to variability in the hydraulic gradient and therefore SGD. Model results indicate the seawater recirculation component of SGD was enhanced during summer while the terrestrial component dominated during winter due to seasonal changes in sea level driven by a combination of long period solar tides, temperature and winds. In one year, sea level remained elevated year round due to a combination of ENSO and NAO climate modes. Hence, predicted changes in regional climate variability driven sea level may impact future rates of SGD and biogeochemical cycling within coastal aquifers.