Conference Papers

Year-round studies of the geothermal impacts of road construction in a "warm" permafrost area were undertaken during 1954-1962 at six road sections across the Richardson and Glenn Highways, in the vicinity of Glennallen, Alaska. As a result, significant information was obtained regarding the temperatures, and changes in temperatures, in the permafrost beneath and adjacent to the highway...

The role of carbon (C) and nitrogen (N) interactions on sequestration of atmospheric CO2 in black spruce ecosystems across North America was evaluated with the Terrestrial Ecosystem Model (TEM) by applying parameterizations of the model in which C-N dynamics were either coupled or uncoupled. First, the performance of the parameterizations, which were developed for the dynamics of black...

The U.S. Geological Survey (USGS) is evaluating the use of hydroacoustic current meters for making discharge measurements in shallow rivers and streams. The USGS historically has made discharge measurements in shallow rivers using mechanical, impellor-type current meters attached to a wading rod. The evaluation project has focused on three categories of hydroacoustic meters: an acoustic...

Sherman Lake, California, has two hydrodynamically distinct regions: a tidally forced jet located along the eastern flank that creates an important hydraulic connection between the Sacramento and San Joaquin Rivers, and a relatively quiescent area in the west. The forcing mechanisms driving circulation and transport are spatially variable in Sherman Lake, a characteristic, we are finding...

Accurate ice-affected streamflow records are difficult to obtain for several reasons. Problems measuring stage, variable backwater conditions, access limitations in wintertime, and problems measuring flowing water under ice cover all contribute to make ice-affected streamflow records less accurate than open-channel streamflow records. The inaccuracy of ice-affected streamflow records is

Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus...

Macroinvertebrates were used to assess the impact of urbanization on stream quality across a gradient of watershed imperviousness in 43 southeastern Wisconsin streams. The percentage of watershed connected imperviousness was chosen as the urbanization indicator to examine impact of urban land uses on macroinvertebrate communities. Most urban land uses were negatively correlated with the...

A cost-effective procedure for calibrating acoustic Doppler current profilers (ADCP) in the field was presented. The advantages and disadvantages of various methods which are used for calibrating ADCP were discussed. The proposed method requires the use of differential global positioning system (DGPS) with sub-meter accuracy and standard software for collecting ADCP data. The method...

The Moon provides an exo-atmospheric radiance source that can be used to determine trends in instrument radio-metric responsivity with high precision. Lunar observations can also be used for absolute radiometric calibration; knowledge of the radiometric scale will steadily improve through independent study of lunar spectral photometry and with sharing of the Moon as a calibration target...

An initial test of the performance of the NASA Experimental Advanced Airborne Research Lidar (EAARL) over coastal environments around the margins of an urbanized Gulf of Mexico estuary was performed over Tampa Bay in January 2002. The EAARL is a raster-scanning, water-penetrating, full-waveform adaptive lidar that is coupled to aircraft positioning systems and a downlooking color digital...

Interferometric synthetic aperture radar (InSAR) imaging is a recently developed geodetic technique capable of measuring ground-surface deformation with centimeter to subcentimeter vertical precision and spatial resolution of tens-of-meter over a relatively large region (/spl sim/10/sup 4/ km/sup 2/). The spatial distribution of surface deformation data, derived from InSAR images...

Launched in April 1999, the Landsat-7 ETM+ instrument is in its fourth year of operation. The quality of the acquired calibrated imagery continues to be high, especially with respect to its three most important radiometric performance parameters: reflective band instrument stability to better than ??1%, reflective band absolute calibration to better than ??5%, and thermal band absolute...