title: Improved Vertical Streambed Flux Estimation Using Multiple Diurnal Temperature Methods in Series.
abstract: Analytical solutions that use diurnal temperature signals to estimate vertical fluxes between groundwater and surface water based on either amplitude ratios (Ar) or phase shifts (Δϕ) produce results that rarely agree. Analytical solutions that simultaneously utilize Arand Δϕ within a single solution have more recently been derived, decreasing uncertainty in flux estimates in some applications. Benefits of combined (ArΔϕ) methods also include that thermal diffusivity and sensor spacing can be calculated. However, poor identification of either Aror Δϕ from raw temperature signals can lead to erratic parameter estimates from ArΔϕ methods. An add-on program for VFLUX 2 is presented to address this issue. Using thermal diffusivity selected from an ArΔϕ method during a reliable time period, fluxes are recalculated using an Armethod. This approach maximizes the benefits of the Arand ArΔϕ methods. Additionally, sensor spacing calculations can be used to identify periods with unreliable flux estimates, or to assess streambed scour. Using synthetic and field examples, the use of these solutions in series was particularly useful for gaining conditions where fluxes exceeded 1 m/d.
authors.affiliation: School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria 3800, Australia.|National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, South Australia, 5001, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Irvine
authors.affiliation: U.S. Geological Survey, Office of Groundwater, Branch of Geophysics, 11 Sherman Place, Unit 5015, Storrs, CT 06269.
authors.forename: M A
authors.initials: MA
authors.lastname: Briggs
authors.affiliation: School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria 3800, Australia.|National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, South Australia, 5001, Australia.
authors.forename: I
authors.initials: I
authors.lastname: Cartwright
authors.affiliation: U.S. Geological Survey, Office of Groundwater, Branch of Geophysics, 11 Sherman Place, Unit 5015, Storrs, CT 06269.
authors.forename: C R
authors.initials: CR
authors.lastname: Scruggs
authors.affiliation: Department of Earth Sciences, Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244.
authors.forename: L K
authors.initials: LK
authors.lastname: Lautz
mesh_terms: D060587:Groundwater; D013696:Temperature; D014867:Water; D014872:Water Movements
chemical_list: D014867:Water