Geology topics

Carl J. Bowser

Publications and source records attributed to Carl J. Bowser.

4 recordsLinked to original sources

USGS2012

The contribution of evaporation from the Great Lakes to the continental atmosphere: estimate based on stable isotope data

The isotopic composition of precipitation and river runoff in the vicinity of the North American Great Lakes is characterized by a higher deuterium-excess value than observed in the advecting air masses. It is suggested that this indicates that evaporated moisture from the surface waters is mixed with the atmosphere waters. A preliminary estimate of the atmospheric water balance during summer and autumn indicates that between 4.6%–15.7% of the atmospheric water content downwind from the Great Lakes is derived from lake evaporation during summer.

Geophysical Research Letters↗

USGS2010

Estimating groundwater exchange with lakes: 1. The stable isotope mass balance method

Groundwater inflow and outflow contributions to the hydrologic budget of lakes can be determined using a stable isotope ( 18 O/ 16 O) mass balance method. The stable isotope method provides a way of integrating the spatial and temporal complexities of the flow field around a lake, thereby offering an appealing alternative to the traditional time and labor intensive methods using seepage meters and an extensive piezometer network. In this paper the method is applied to a lake in northern Wisconsin, demonstrating that it can be successfully applied to lakes in the upper midwest where thousands of similar lakes exist. Inflow and outflow rates calculated for the Wisconsin lake using the isotope mass balance method are 29 and 54 cm/yr, respectively, which compare well to estimates, derived independently using a three-dimensional groundwater flow and solute transport model, of 20 and 50 cm/yr. Such a favorable comparison lends confidence to the use of the stable isotope method to estimate groundwater exchange with lakes. In addition, utilization of stable isotopes in studies of groundwater-lake systems lends insight into mixing processes occurring in the unsaturated zone and in the aquifer surrounding the lake and verifies assumed flow paths based on head measurements in piezometers.

Wisconsin↗

USGS2010

Estimating groundwater exchange with lakes: 2. Calibration of a three-dimensional, solute transport model to a stable isotope plume

A three-dimensional groundwater flow and solute transport model was calibrated to a plume of water described by measurements of δ 18 O and used to calculate groundwater inflow and outflow rates at a lake in northern Wisconsin. The flow model was calibrated to observed hydraulic gradients and estimated recharge rates. Calibration of the solute transport submodel to the configuration of a stable isotope ( 18 O) plume in the contiguous aquifer on the downgradient side of the lake provides additional data to constrain the model. A good match between observed and simulated temporal variations in plume configuration indicates that the model closely simulated the dynamics of the real system. The model provides information on natural variations of rates of groundwater inflow, lake water outflow, and recharge to the water table. Inflow and outflow estimates compare favorably with estimates derived by the isotope mass balance method (Krabbenhoft et al., this issue). Model simulations agree with field observations that show groundwater inflow rates are more sensitive to seasonal variations in recharge than outflow.

Wisconsin↗

USGS2009

Use of oxygen-18 and deuterium to assess the hydrology of groundwater-lake systems

A thorough understanding of a lake's hydrology is essential for many lake studies. In some situations the interactions between groundwater systems and lakes are complex; in other cases the hydrology of a multilake system needs to be quantified. In such places, stable isotopes offer an alternative to the more traditional piezometer networks, which are costly to install and time-consuming to maintain. The stable-isotope mass-balance relations presented here can be used to estimate groundwater exchange rates for individual lakes and geographically clustered lakes. These relations also can be used to estimate other hydrological factors, such as average relative humidity. In places where the groundwater system is unstable (e.g., where flow reversals occur), natural solute tracers may provide a better alternative than stable isotopes for estimating rates of groundwater flow to and from lakes.

Book chapter↗