2,443 research outputs found

    Analysis and use of VAS satellite data

    Get PDF
    A series of interrelated investigations has examined the analysis and use of VAS (VISSR Atmospheric Sounder) satellite data. A case study of VAS-derived mesoscale stability parameters suggested that they would have been a useful supplement to conventional data in the forecasting of thunderstorms on the day of interest. However, the meteorological significance of small or short lived stability features was uncertain. A second investigation examined the roles of first guess and VAS radiometric data in producing sounding retrievals. The radiance data often did not have a decisive influence on the final satellite soundings. Broad-scale patterns of the first guess, radiances, and retrievals frequently were similar, whereas small scale retrieval features, especially in the dew points, were often of uncertain origin

    Analysis and use of VAS satellite data

    Get PDF
    Four interrelated investigations have examined the analysis and use of VAS satellite data. A case study of VAS-derived mesoscale stability parameters suggested that they would have been a useful supplement to conventional data in the forecasting of thunderstorms on the day of interest. A second investigation examined the roles of first guess and VAS radiometric data in producing sounding retrievals. Broad-scale patterns of the first guess, radiances, and retrievals frequently were similar, whereas small-scale retrieval features, especially in the dew points, were often of uncertain origin. Two research tasks considered 6.7 micron middle tropospheric water vapor imagery. The first utilized radiosonde data to examine causes for two areas of warm brightness temperature. Subsidence associated with a translating jet streak was important. The second task involving water vapor imagery investigated simulated imagery created from LAMPS output and a radiative transfer algorithm. Simulated image patterns were found to compare favorably with those actually observed by VAS. Furthermore, the mass/momentum fields from LAMPS were powerful tools for understanding causes for the image configurations

    Researchers explore Arctic freshwater\u27s role in ocean circulation

    Get PDF
    A critical, but insufficiently understood, component of global change is the influence of Arctic freshwater input on water mass exchange between the Arctic Ocean and Atlantic and Pacific Oceans. Four of the Earth\u27s 10 largest river systems, the Mackenzie, Ob,Yenisei, and Lena, contribute water to the Arctic shore (Figure 1) from a vast watershed that drains continental interiors. This river discharge flows into the world\u27s largest contiguous continental shelf and supplies over 50% (1823 km3 ) of the riverine input to the Arctic Ocean

    Performance of Westslope Cutthroat Trout Released into the Upper Cherry Creek Drainage Using Remote Stream Incubators

    Get PDF
    A major effort to conserve westslope cutthroat (Oncorhynchus clarkii lewisi; WCT) is underway throughout Montana. One of the larger WCT conservation projects is onging in the Cherry Creek drainage of the Madison River. About 105 km of stream and a mountain lake are being treated with piscicides to remove nonnative trout, and WCT are being introduced into the drainage using remote stream incubators (RSIs). We are evaluating the relative success of different wild and hatchery stocks of WCT released into Cherry Creek. Here, we report on survival, abundance, growth, condition, and dispersal of WCT in the upper Cherry Creek drainage during the first three years of releases. Two streams of similar size, upper Cherry Creek and Cherry Lake Creek, meet to form main Cherry Creek. Cherry Lake Creek is colder than upper Cherry Creek (average August temperature about 3?C colder).Known numbers of WCT embryos were placed into RSIs at two sites in upper Cherry Creek during 2006 and 2007, one site in Cherry Lake Creek during 2006 and 2007, one site in Pika Creek (a tributary to Cherry Lake Creek) during 2008, and in an un-named spring-fed tributary to main Cherry Creek just below the mouth of Cherry Lake Creek during 2008. Fry that hatched in each RSI were captured and counted prior to release. Population abundances were estimated by single and multiple-pass electrofishing in 100-m sample sections located systematically throughout the upper reaches of the drainage. Estimated survivals from egg to fry, fry to age- 1, age-1 to age-2, and age-2 to age-3 ranged from 13 to 80 percent, 7 to 80 percent, 21 to 100 percent, and 100 percent, respectively. Survivals in the colder stream, Cherry Lake Creek, were lower than in the warmer stream. Over 3500 WCT occupied the upper Cherry Creek drainage by 2009. Fish dispersed short distances upstream and long distances downstream, but downstream dispersal appeared relatively discrete, with WCT filling available habitat near RSIs before occupying reaches further downstream. Early growth of WCT was much slower in colder streams, but by age-3 little difference existed among streams. Conversely, condition factors of WCT were slightly lower in upper Cherry Creek (averaging 0.88 to 0.95) than in Cherry Lake Creek (0.92 to 1.11). The introduction of WCT in upper Cherry Creek has been successful to date; however, natural reproduction by introduced WCT has not yet occurred, but is expected to occur next year

    Thermal Adaptation of Westslope Cutthroat Trout

    Get PDF
    Populations of westslope cutthroat trout (Oncorhynchus clarkii lewisi), a State species of special concern, have declined throughout their native range. Genetic introgressions, mainly from rainbow trout (O. mykiss), but also from Yellowstone cutthroat trout (O. c. bouvieri), and habitat loss are believed to be the leading causes of this decline. Populations that remain are often small and isolated, thereby increasing their risk of inbreeding depression and extinction. Translocation projects may offer a solution by infusing new genetic material into populations and potentially increasing their probability of persistence. However, local adaptations must be considered when selecting a donor population. We investigated thermal adaptations of four wild populations of westslope cutthroat trout from the Missouri River drainage and one hatchery population from the Washoe Park Trout Hatchery, Anaconda, Montana. Two wild populations were deemed to be from warm streams and two from cold streams. Fish were spawned streamside and at the hatchery. The resulting embryos were placed in experimental systems at 8, 10, and 14 °C. Survival was monitored throughout incubation. Post-embryonic growth was measured 90 days after hatching. Relationships between population performance and natal stream thermal characteristics were examined for adaptive differences

    Quantification of storm-induced bathymetric change in a back-barrier estuary

    Get PDF
    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 40 (2017): 22-36, doi:10.1007/s12237-016-0138-5.Geomorphology is a fundamental control on ecological and economic function of estuaries. However, relative to open coasts, there has been little quantification of storm-induced bathymetric change in back-barrier estuaries. Vessel-based and airborne bathymetric mapping can cover large areas quickly, but change detection is difficult because measurement errors can be larger than the actual changes over the storm timescale. We quantified storm-induced bathymetric changes at several locations in Chincoteague Bay, Maryland/Virginia, over the August 2014 to July 2015 period using fixed, downward-looking altimeters and numerical modeling. At sand-dominated shoal sites, measurements showed storm-induced changes on the order of 5 cm, with variability related to stress magnitude and wind direction. Numerical modeling indicates that the predominantly northeasterly wind direction in the fall and winter promotes southwest-directed sediment transport, causing erosion of the northern face of sandy shoals; southwesterly winds in the spring and summer lead to the opposite trend. Our results suggest that storm-induced estuarine bathymetric change magnitudes are often smaller than those detectable with methods such as LiDAR. More precise fixed-sensor methods have the ability to elucidate the geomorphic processes responsible for modulating estuarine bathymetry on the event and seasonal timescale, but are limited spatially. Numerical modeling enables interpretation of broad-scale geomorphic processes and can be used to infer the long-term trajectory of estuarine bathymetric change due to episodic events, when informed by fixed-sensor methods

    Researchers Explore Arctic Freshwater's Role in Ocean Circulation

    Get PDF
    This article is available at University of New Hampshire Scholars' Repository: https://scholars.unh.edu/faculty_pubs/149National Science FoundationGrant ATM-981826

    The effect of lysine level or methionine/copper/manganese on osteochondrosis lesions and cartilage properties in pigs

    Get PDF
    A total of 120 gilts (PIC 327 × 1050; 89.2 lb initial BW) were used in a 3 × 2 factorial, 84-d study to determine the effect of lysine (Lys) fed either below the calculated requirement (0.8% true ileal digestible (TID) Lys Phase I and 0.6% TID Lys Phase II), at requirement (1.0% TID Lys Phase I and 0.8% TID Lys Phase II), or above the requirement (1.3% TID Lys Phase I and 1.1% TID Lys Phase II) with standard concentrations or with high added methionine (Met, 1 %), copper sulfate (Cu, 250 ppm), and manganese sulfate (Mn, 220 ppm) on the occurrence and severity of osteochondrosis (OC) lesions, growth performance, soundness, carcass traits, and several cartilage criteria. Upon completion of the feeding period, pigs were harvested and the distal aspect of the left humerus and femur were evaluated by gross examination for OC lesions. The external surface was evaluated for abnormalities and received a severity score. For the external femur evaluation, increasing dietary Lys concentration tended (linear, P\u3c0.08) to increase the number of abnormalities and there was a numerical trend for an increased severity score (P\u3c0.13) with increasing dietary Lys. The addition of high Met/Cu/Mn to the diet reduced the number of abnormalities (P\u3c0.02) and severity score (P\u3c0.01) at the external femur compared to pigs fed diets with standard concentrations of Met/Cu/Mn. At the external humerus, increasing dietary Lys increased both the number of abnormalities (linear, P\u3c0.01) and severity score (linear, P\u3c0.01). The addition of high Met/Cu/Mn to the diet reduced the number of abnormalities (P\u3c0.03) and severity score (P\u3c0.03) for the external humerus. Increasing dietary Lys concentration or high-added Met/Cu/Mn had no effect (P\u3e0.14) on the number of faces with lesions at the femoral growth plate or the severity score (P\u3e0.19). The number of faces with lesions and severity score at the humerus articular cartilage was unaffected by increasing dietary Lys concentration (P\u3e0.16) or the addition of high Met/Cu/Mn to the diet (P\u3e0.37). The total faces with lesions were not impacted by increasing dietary Lys concentration (P\u3e0.78) or additional high Met/Cu/Mn (P\u3e0.86). The total abnormalities (external and number of faces) tended to increase with increasing dietary Lys (linear, P\u3c0.12). The addition of high Met/Cu/Mn did not affect the total number of abnormalities (P\u3e0.16). The total severity score for both external and OC evaluation increased with increasing dietary Lys concentration (linear, P\u3c0.01). The addition of high Met/Cu/Mn decreased the total severity score (P\u3c0.02) compared to pigs fed diets with standard concentrations of Met/Cu/Mn. Finally, increasing dietary Lys concentration increased the sum (linear, P\u3c0.05) of abnormalities and total severity score. The addition of high Met/Cu/Mn tended (P\u3c0.09) to reduce the overall severity score compared to pigs fed diets with standard concentrations of Met/Cu/Mn. In conclusion, feeding growing gilts dietary Lys to maximize growth performance may increase the severity of OC lesions, while a diet with additional Met/Cu/Mn may aid in the reduction of OC severity scores.; Swine Day, 2007, Kansas State University, Manhattan, KS, 200

    A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects

    Get PDF
    © 2018 ESO. Reproduced with permission from Astronomy & Astrophysics.Context. Young stellar objects (YSOs) may undergo periods of active accretion (outbursts), during which the protostellar accretion rate is temporarily enhanced by a few orders of magnitude. Whether or not these accretion outburst YSOs possess similar dust and gas reservoirs to each other, and whether or not their dust and gas reservoirs are similar as quiescent YSOs, are issues yet to be clarified.Aims. The aim of this work is to characterize the millimeter thermal dust emission properties of a statistically significant sample of long and short duration accretion outburst YSOs (i.e., FUors and EXors) and the spectroscopically identified candidates of accretion outbursting YSOs (i.e., FUor-like objects). Methods. We have carried out extensive Submillimeter Array (SMA) observations mostly at ~225 GHz (1.33 mm) and ~272 GHz (1.10 mm), from 2008 to 2017. We covered accretion outburst YSOs located at 3σ significance. Detected sources except for the two cases of V883 Ori and NGC 2071 MM3 were observed with ~1″ angular resolution. Overall our observed targets show a systematically higher millimeter luminosity distribution than those of the M ∗ > 0.3 MClass II YSOs in the nearby (400 pc) low-mass star-forming molecular clouds (e.g., Taurus, Lupus, Upp Scorpio, and Chameleon I). In addition, at 1 mm our observed confirmed binaries or triple-system sources are systematically fainter than the rest of the sources even though their 1 mm fluxes are broadly distributed. We may have detected ∼30-60% millimeter flux variability from V2494 Cyg and V2495 Cyg, from the observations separated by approximately one year.Peer reviewe

    On SIC-POVMs in Prime Dimensions

    Full text link
    The generalized Pauli group and its normalizer, the Clifford group, have a rich mathematical structure which is relevant to the problem of constructing symmetric informationally complete POVMs (SIC-POVMs). To date, almost every known SIC-POVM fiducial vector is an eigenstate of a "canonical" unitary in the Clifford group. I show that every canonical unitary in prime dimensions p > 3 lies in the same conjugacy class of the Clifford group and give a class representative for all such dimensions. It follows that if even one such SIC-POVM fiducial vector is an eigenvector of such a unitary, then all of them are (for a given such dimension). I also conjecture that in all dimensions d, the number of conjugacy classes is bounded above by 3 and depends only on d mod 9, and I support this claim with computer computations in all dimensions < 48.Comment: 6 pages, no figures. v3 Refs added, improved discussion of previous work. Ref to a proof of the main conjecture also adde
    corecore