975 research outputs found

    Analysis of field measurements of carbon dioxide and water vapor fluxes

    Get PDF
    Analysis of the field measurements of carbon dioxide and water vapor fluxes is discussed. These data were examined in conjunction with reflectance obtained from helicopter mounted Modular Multiband Radiometer. These measurements are representative of the canopy scale (10 to 100 m)(exp 2) and provide a good basis for investigating the hypotheses/relationship potentially useful in remote sensing applications. All the micrometeorological data collected during FIFE-89 were processed and fluxes of CO2, water vapor, and sensible heat were calculated. Soil CO2 fluxes were also estimated. Employing these soil CO2 flux values, in conjunction with micrometeorological measurements, canopy photosynthesis is being estimated. A biochemical model of leaf photosynthesis was adapted to the prairie vegetation. The modeled leaf photosynthesis rates were scaled up to the canopy level. This model and a multiplicative stomatal conductance model are also used to calculate canopy conductance

    Analysis of soil and species composition

    Get PDF
    Measurements were made during May to October, 1987 and June to August, 1989 over a tallgrass prairie near Manhattan, Kansas. Soil at the experimental site is predominantly Dwight silty clay loam. The prairie was burned on 16 April 1987 and on 28 April 1989 to improve the mix of grasses and forbs. The experimental area was not grazed during 1986 - 1989. A summary of results are given for soil moisture and plant growth; momentum flux and canopy aerodynamic characteristics; evapotranspiration, components of energy balance and canopy conductance; modeling canopy stomatal conductance; canopy photosynthesis, photosynthetic efficiency and water use efficiency; modeling canopy photosynthesis; the carbon dioxide budget in a temperate grassland ecosystem; and photosynthesis and stomatal conductance related to reflectance on the canopy scale

    Stable configurations of hybrid stars with colour-flavour-locked core

    Full text link
    We construct static and mass-shedding limit sequences of hybrid stars, composed of colour flavour locked (CFL) quark matter core, for a set of equations of state (EOSs). The EOS for the hadronic matter is obtained using appropriately calibrated extended field theoretical based relativistic mean-field model. The MIT bag model is employed to compute the EOSs of the CFL quark matter for different values of the CFL gap parameter in the range of 50150MeV50 - 150\text{MeV} with the deconfinement phase transition density ranging from 4ρ06ρ04\rho_0 - 6\rho_0 (ρ0=0.16fm3\rho_0 = 0.16\text{fm}^{-3}). We find, depending on the values of the CFL gap parameter and the deconfinement phase transition density, the sequences of stable configurations of hybrid stars either form third families of the compact stars or bifurcate from the hadronic sequence. The hybrid stars have masses 1.02.1M1.0 - 2.1 M_\odot with radii 913.59 - 13.5 km. The maximum values of mass shedding limit frequency for such hybrid stars are 121 -2 kHz. For the smaller values of the CFL gap parameter and the deconfinement phase transition density, mass-radius relationships are in harmony with those deduced by applying improved hydrogen atmosphere model to fit the high quality spectra from compact star X7 in the globular cluster 47 Tucanae. We observed for some cases that the third family of compact stars exist in the static sequence, but, disappear from the mass-shedding limit sequence. Our investigation suggests that the third family of compact stars in the mass-shedding limit sequence is more likely to appear, provided they have maximum mass in the static limit higher than their second family counterpart composed of pure hadronic matter.Comment: 27 pages including 10 figures. Accepted in Phys. Rev.

    Modeling Canopy Stomatal Conductance in a Temperate Grassland Ecosystem

    Get PDF
    corecore