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At least 163 records · Page 9

Trophic classification of selected Colorado lakes

Multispectral scanner data, acquired over several Colorado lakes using LANDSAT-1 and aircraft, were used in conjunction with contact-sensed water quality data to determine the feasibility of assessing lacustrine trophic levels. A trophic state index was developed using contact-sensed data for several trophic indicators. Relationships between the digitally processed multispectral scanner data, several trophic indicators, and the trophic index were examined using a supervised multispectral classification technique and regression techniques. Statistically significant correlations exist between spectral bands, several of the trophic indicators and the trophic state index. Color-coded photomaps were generated which depict the spectral aspects of trophic state.

Blackwell, R. J.↗

Trophic classification of Colorado lakes utilizing contact data, Landsat and aircraft-acquired multispectral scanner data

Multispectral scanner data, acquired over several Colorado lakes using Landsat-1 and aircraft, were used in conjunction with National Eutrophication Survey contact-sensed data to determine the feasibility of assessing lacustrine trophic levels. A trophic state index was developed using contact-sensed data for several trophic indicators (chlorophyll a, inverse of Secchi disk transparency, conductivity, total phosphorous, total organic nitrogen, algal assay yield). Relationships between the digitally processed multispectral scanner data, several trophic indicators, and the trophic index were examined using a supervised multispectral classification technique and regression techniques. Statistically significant correlations exist between spectral bands, several of the trophic indicators (chlorophyll a, Secchi disk transparency, total organic nitrogen), and the trophic state index. Color-coded photomaps were generated which depict the spectral aspects of trophic state. Multispectral scanner data acquired from satellite and aircraft platforms can be used to advantage in lake monitoring and survey programs.

Boland, D. H. P.↗

Solar energy system economic evaluation for Colt Pueblo, Pueblo, Colorado

The Solar Energy System is not economically beneficial under the assumed economic conditions at Pueblo, Colorado; Yosemite, California; Albuquerque, New Mexico; Fort Worth, Texas; and Washington, D.C. Economic benefits from this system depend on decreasing the initial investment and the continued increase in the cost of conventional energy. Decreasing the cost depends on favorable tax treatment and continuing development of solar energy technology. Fuel cost would have to increase drastically while the cost of the system would have to remain constant or decrease for the system to become economically feasible.

Source record↗

Active microwave investigation of snowpacks: Experimental documentation, Colorado 1979-1980

During the winter of 1979-1980, the University of Kansas Microwave Active Spectrometer systems measured the backscattering properties of snowpacks under varying conditions at four test sites in Colorado. In addition to the radar data over 1-35 GHz, ground-truth measurements of the atmospheric, snow, and soil characteristics were obtained for each radar data set. The test sites, data acquisition procedures, and data that were acquired in this experiment are presented and described.

Stiles, W. H.↗

Applications systems verification and transfer project. Volume 4: Operational applications of satellite snow cover observations. Colorado Field Test Center

The study was conducted on six watersheds ranging in size from 277 km to 3460 km in the Rio Grande and Arkansas River basins of southwestern Colorado. Six years of satellite data in the period 1973-78 were analyzed and snowcover maps prepared for all available image dates. Seven snowmapping techniques were explored; the photointerpretative method was selected as the most accurate. Three schemes to forecast snowmelt runoff employing satellite snowcover observations were investigated. They included a conceptual hydrologic model, a statistical model, and a graphical method. A reduction of 10% in the current average forecast error is estimated when snowcover data in snowmelt runoff forecasting is shown to be extremely promising. Inability to obtain repetitive coverage due to the 18 day cycle of LANDSAT, the occurrence of cloud cover and slow image delivery are obstacles to the immediate implementation of satellite derived snowcover in operational streamflow forecasting programs.

Shafer, B. A.↗

Measurements of stratospheric aerosols over Mauna Loa, Hawaii and Boulder, Colorado

The direct solar radiation transmission record at Mauna Loa, dating from 1958 to the present, revealed with remarkable precision the presence of stratospheric aerosol from volcanic activity. This record can be used to quantify the intensity of the stratospheric volcanic aerosol perturbation following a significant eruption in reference to the Agung event in 1963. The Mount St. Helens' stratospheric cloud was first detected by lidar at 18 km over Mauna Loa on 17 July. The atmospheric transmission was seen to decrease slightly after that time, but only a few tenths of 1 percent. Although it is still fairly early to draw a definite conclusion on the ultimate magnitude of the Mount St. Helens stratospheric aerosol from the Mauna Loa results, it can be stated that the stratospheric aerosol optical depth presently observed is comparable with that observed from Fuego which erupted in 1974. At Boulder, Colorado, the atmospheric debris from Mount St. Helens was observed by lidar on a number of occasions. Also, observations of the diffuse, total and direct transmission of solar radiation were made on June 3 and 4. The latter set of observations is useful for deriving information on the scattering properties of the volcanic cloud. The lidar and solar radiation data are presented and some of their special features are discussed.

Deluisi, J. J.↗

Mount St. Helens dust veil observed at Boulder, Colorado by optical techniques

Following the May 18, 1980, eruption of Mount St. Helens, photometric and photograhic observations were taken at Boulder, Colorado, to record the optical effects of volcanic dust atmospherically transported to this area. The instruments used included a narrow-beamwidth solar photometer which recorded solar irradiance in eight narrow-bandwidth channels in the wavelength range 0.3 to 1.1 microns, a solar aureole photometer, and two time-lapse camera systems. The eight-channel solar photometer data have been analyzed to obtain the wavelength dependence of optical thickness. At the longer wavelengths, on May 20, 1980, the optical thickness was as much as nine times that expected from a 'clean atmosphere' model. During the first several days following the eruption, the dust veil sometimes exhibited sufficient spatial structure that its motion can be seen on the time-lapse films. The results of analysis to date are presented and the plans for additional analysis are outlined.

Lerfald, G.↗

A correlation analysis of percent canopy closure versus TMS spectral response for selected forest sites in the San Juan National Forest, Colorado

The correlation of canopy closure with the signal response of individual thematic mapper simulator (TMS) bands for selected forest sites in the San Juan National Forest, Colorado was investigated. Ground truth consisted of a photointerpreted determination of percent canopy closure of 0 to 100 percent for 32 sites. The sites selected were situated on plateaus at an elevation of approximately 3 km with slope or = 10 percent. The predominant tree species were ponderosa pine and aspen. The mean TMS response per band per site was calculated from data acquired by aircraft during mid-September, 1981. A correlation analysis of TMS response vs. canopy closure resulted in the following correlation coefficients for bands 1 through 7, respectively: -0.757, -0.663, -0.666, -0.088, -0.797, -0.763. Two model regressions were applied to the TMS data set to create a map of predicted percent forest canopy closure for the study area. Results indicated percent predictive accuracies of 71, 74, and 57 for percent canopy closure classes of 0-25, 25-75, and 75-100, respectively.

Butera, M. K.↗

Volcanism of the Colorado Plateau - Basin and Range Transition: Implications for Crustal Processes

On the Colorado Plateau-Basin and Range transition in Arizona and New Mexico, basaltic volcanism takes two physiographic forms: (1) Major central composite volcanoes (e.g., San Francisco Peaks) in which basaltic magma differentiates at shallow crustal levels to siliceous and members and (2) large numbers of small cinder cones and a few domes that result from numerous discrete magma batches which apparently had little opportunity for differentiation. This study represents the first look at the petrogenesis of Plateau-bounding volcanic fields, based on rigorous stratigraphic controls, in combination with major and trace-element constraints. The emerging pattern of large volcanic constructs associated with shallow fractional crystallization, and numerous cinder cones associated with limited or no shallow differentiation may provide an analogue for interpreting petrogenetic patterns and/or tectonic settings on Mars.

Condit, C. D.↗

Performance of the Colorado wind-profiling network, part 1.5A

The Wave Propagation Laboratory (WPL) has operated a network of radar wind Profilers in Colorado for about 1 year. The network consists of four VHF (50-MHz) radars and a UHF (915-MHz) radar. The Platteville VHF radar was developed by the Aeronomy Laboratory (AL) and has been operated jointly by WPL and AL for several years. The other radars were installed between February and May 1983. Experiences with these radars and some general aspects of tropospheric wind measurements with Doppler radar are discussed.

Strauch, R. G.↗

Data base for the Colorado profiling network

The Colorado profiling system developed by the Wave Propagation Laboratory (WPL) includes five (soon to be six) Doppler radar wind Profilers; four operate at 49 MHz (6 m) and are located at Platteville, Fleming, Lay Creek, and Cahone, and one operates at 915 MHz (33 cm) and is located at Denver. The sixth radar, now under construction, will operate at 405 MHz (UHF) and will be located at Boulder. Microwave radiometers and surface meteorological stations are at some of the radar sites. The data base for the wind Profilers is discussed.

Merritt, D. A.↗

CU in space: The University of Colorado get away special payload G-285

The University of Colorado's first Get Away Special was conceived by a dozen science and engineering students in the spring of 1984. Since that time, the project has grown to include over 100 undergraduate and graduate students who have 'provided the experimental objectives, design, construction, integration, testing and management of the payload. Faculty and staff of the university and its affiliated laboratories as well as engineers from local industries have provided many useful suggestions at all stages of development. The principal motivation for developing this payload is to provide university students with the opportunity to participate in space science and engineering beginning at the ground level. At the same time, they are contributing their results from new science and technological discoveries to several disciplines. There are four separate experiments integrated into the /'single payload of G-285 which are supported by internal payload !power, thermal environment control, command land data handling [ facilities and structural subsystems. The four experiments contained in this payload are: a single spectrometer performing i two experiments- one to study night time shuttle glow phenomena in the ultraviolet and the other to observe NO2 concentrations over / equatorial latitudes in the day; a fluids management experiment ' using centrifugation for particle/liquid/vapor separation; and an experiment using Phycomyces fungi to study the gravireceptor mechanism theory. The experiments are supported by a microprocessor, data storage devices, power and thermal control subsystems. All these are located within a sealed aluminum container. The container, a refitted sounding rocket casing, has a top and bottom which bolt to the main body of the rocket section. The top section holds a five inch diameter quartz window through which light enters the spectrometer. A rotating mirror assembly and one of two battery boxes are mounted on the outside of the top section below the interface plane of the MDA. A second battery box is attached to the bottom section of the sealed container. All payload items except the battery boxes and mirror assembly are located inside the sealed rocket section to insure containment and to prevent outgassing of materials. The container will be sealed prior to launch and purged with one atmosphere of argon.

Kent Tobiska↗

Thermomechanical modeling of the Colorado Plateau-Basin and range transition zone

The Colorado Plateau (CP) basin and range (B & R) boundary is marked by a transition zone on the order of 75 to 150 km in width. As one moves westward across this transition from the CP interior to the B & R there is a variation in the surface topography, surface heat flow, Bouguer gravity, seismicity, and crustal structure. This transition extends eastward into the western CP from the Wastach-Hurricane fault line and is largely coincident with the high plateaus of Utah and the Wasatch Mountains. It has been suggested that this transition zone marks a thermal and tectonic encroachment of the CP by the B & R. A simple two dimensional numerical model of the thermal regime for the transition zone was constructed to test the hypothesis that the observed geophysical signatures across the transition are due to lateral heat conduction from steady state uniform extension within the B & R lithosphere. Surface heat flow, uplift due to flexure from thermal buoyant loading, and regional Bouguer gravity are computed for various extension rates, crustal structures, and compensation depths.

Londe, M. D.↗

Geologic results of the TMS survey over Mt. Emmons, Colorado

In 1981, NASA conducted with an American company a cooperative study, involving the use of Thematic Mapper Simulator (TMS) data. The study was concerned with an area near Crested Butte, Colorado, which contains a known, but unmined, major molybdenum deposit. Detailed ground observations in the Mt. Emmons area demonstrated that the imagery was extremely effective for detection of geologically significant features. The imagery specifically delineated areas of ferric iron staining, seritization, and hornfelized rock. Attention is given to data acquisition and data processing, field work in 1982 and in 1983, the integration of gravity data, and costs.

Rickman, D. L.↗

On the cenozoic uplift and tectonic stability of the Colorado Plateau

Models of plateau uplift which can be applied to the Colorado Plateau are presented. The sequence and consequences of the 2-km Cenzoic uplift of the Plateau and volcanism and rifting in the adjoining Basin and Range and Southern Rocky Mountain-Rio Grande rift provinces are examined. Geologic and geophysical data suggest that more than one mechanism is required to explain the 2 km of uplift, and that thermal expansion and magmatic crustal thickening are the dominant mechanisms. It is argued that the early Cenzoic stability of the Plateau was related to the relatively cool geotherm and hence high strength of the Plateau lithosphere relative to the adjoining regions. As the Plateau lithosphere has been heated and uplift has occurred, the overall stability of the Plateau has decreased.

Morgan, P.↗

Colorado wind profilers

The Wave Propagation Laboratory (WPL) has operated a network of wind profiling radars in Colorado. The current configuration of the network is described. All radars operate continuously and unattended to supply hourly-averaged wind profiles to a central computer in Boulder in real time. The hardware and software changes made to improve reliability are discussed. This research network will continue to be used to provide wind profiles for operational and research meteorologists and the performance of various wavelength systems will be evaluated.

Strauch, R. G.↗

Diurnal and spatial variability of lightning activity in northeastern Colorado and central Florida during the summer

Lightning location data from northeastern Colorado and central Florida for the summer months of 1983 have been studied to ascertain the diurnal development of spatial distributions of flash frequencies. The data sources are discussed, and for both investigated regions, the regional geographic and climatic characteristics, the day-to-day variability of lightning activity, the diurnal cycle over the entire region, the spatial distribution of lightning activity, the diurnal changes of spatial distribution, and the diurnal variation of lightning at individual sites are described in detail. In both regions, the time and space distributions of lightning are modulated by the topographic features and the contrasts of the terrain. Lightning activity is a relatively rare and variable phenomenon in both regions when day-to-day frequencies are considered. There thus must be meteorological parameters that determine the extent and frequency of lightning occurrence.

Lopez, R. E.↗