44 research outputs found

    Influences of Exposure on PAN Evaporation in a Mountainous Area

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    The effects of exposure on pan evaporation rates were studied at the Davis County Experimental Watershed near Farmington, Utah, by operating a network of 12 class A evaporation stations on the watershed during the summer months of 1962 through 1966. Standard Weather Bureau observations on a daily basis were obtained from a total of 17 different sites representing widely idverse topography with a vertical range of 4, 630 feet. Deviations from mean relations with elevation on monthly values of observed meteorological factors were found to be related to the type of exposure. Dewpoint observations on different slopes were found to be related not only to the differences in station exposure but also to the stability of the air and direction of the upper air flow. Two commonly-used methods for estimating monthly pan evaporation were found to be within 3 and 6 percent ofobserved values from the mountain area. Estimates of daily pan evaporation using the mass transfer equations derived from the Lake Hefner and Lake Mean water-loss investigations were found to over-estimate and under-estimate for different types of exposures. The errors in the daily estimates were related to the type of exposure and stability indices. Revised mass transfer equestions were found to correlate well with daily and 2-hourly pan evaporation rates when type of exposure was considered. Further improvement was obtained in the reliability of the mass transfer equestions when the daily data were segregated on the basis of the diretion and speed of the 700-millibar lelvel wind. Pan evaporation for the network stations for open locatiosn on top of major ridges and along their southern slopes and on sites subject to strong night time drainage winds were found to have no discernable variation with elevation. For protected sites and those on northern slopes, pan evaporation showed a small decrease with increasin gelevation. The effect of elevation (atmosphere pressure) independently on evaporation rates was investigated through the use of data from stations where the other meteorological factors involved, other than pressure, were the same. The study indicated that pan evaporation increases with increase in pressure, all other factors considered being the same

    Remote sensing of hydrologic variables in boreal areas, phase 2

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    During Phase 2 airborne Gamma Radiation measurements were conducted over 48 BOREAS (boreal ecosystem atmosphere study) flight lines. Ground measurements of the soil moisture (SM) of the mineral soil and the depth and water content (WC) of the moss/humus layer were collected for calibration of the flight lines. Special attention has been given to the flight lines over, and near, the primary tower sites in the southern study area (SSA); Old Black Spruce (OBS), Old Jack Pine, Old Aspen, and Young Aspen. Multiple ground surveys (September 1993, July, August, and September 1994) show the variation of the water content of the moss/humus layers and changes in the amount of standing water near the SSA OBS tower during the period September 1993 to September 1994. All ground data, airborne estimates and locations of flight lines and ground sampling points have been submitted to BORIS (BOREAS Information System). On 8-10 September 1994 exceptionally high values of cosmic radiation were observed by the airborne gamma radiation system over the SSA. Follow up investigation has not determined the source of, or what caused, the high cosmic count rates

    Remote sensing of hydrologic variables in boreal areas, phase 1

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    The major effort by HYD-6 members has been to develop a network of flight lines to provide the maximum amount of information on the temporal and spatial variation in soil moisture for the Boreal Ecosystem Atmosphere Study (BOREAS) study areas. Field visits to the southern study area (SSA) were conducted during May 1993 to obtain first hand information on the flight lines that had been previously selected for BOREAS snow studies. In September 1993 airborne gamma radiation surveys were conducted over the SSA, the northern study area (NSA), and for five flight lines along the transect between the two study areas. In situ measurements of soil moisture and water content of the moss/humus layer were obtained for calibration of selected gamma radiation flights lines in the SSA and for two of the transit lines. The flight lines for which soil moisture will be measured during the three IFC's during the summer of 1994 is a subset of the total flight lines that have been flown for the snow surveys. During the WFC in February 1994, airborne gamma radiation surveys were flown over all of the flight lines. Members of HYD-4 collected in-situ measurements (soil moisture, water content of the moss/humus layer, and water equivalent of the snow cover)

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    BOREAS HYD-6 Aircraft Gamma Ray Soil Moisture Data

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    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-6 team collected several data sets related to the moisture content of soil and overlying humus layers. This data set contains percent soil moisture (by weight) (and/or water content if there is a moss/humus layer) measured from aircraft using a terrestrial gamma ray instrument. There are also data that indicate the location of the aircraft at the time it collected the terrestrial gamma ray data for the various flight lines and bins. The location information contains a list of coordinates that indicate the path of the aircraft for each bin. The data were collected during four time periods from September 1993 to September 1994 over the southern study area (SSA) and two time periods from February to August 1994 over the northern study area (NSA). The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC)

    BOREAS HYD-6 Moss/Humus Moisture Data

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    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-6 team collected several data sets related to the moisture content of soil and overlying humus layers. This data set contains water content measurements of the moss/humus layer, where it existed. These data were collected along various flight lines in the Southern Study Area (SSA) and Northern Study Area (NSA) during 1994. The data are available in tabular ASCII files. The HYD-06 moss/humus moisture data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884)
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