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101.
Dragutin T. Mihailovic Jelena Lazic Jacek Leśny Janusz Olejnik Branislava Lalic Darko Kapor Ana Cirisan 《Theoretical and Applied Climatology》2010,100(3-4):299-323
Numerical simulations and tests with the recently redesigned land–air parameterization scheme (LAPS) are presented. In all experiments, supported either by one-point micrometeorological, 1D or 3D simulations, the attention has been directed to: (1) comparison of simulation outputs, expressing the energy transfer over and through heterogeneous and non-heterogeneous surfaces, versus observations and (2) analysis of uncertainties occurring in the solution of the energy balance equation at the land–air interface. To check the proposed method for aggregation of albedo, “propagating hole” sensitivity tests with LAPS over a sandstone rock grid cell have been performed with the forcing meteorological data for July 17, 1999 in Baxter site, Philadelphia (USA). Micrometeorological and biophysical measurements from the surface experiments conducted over crops and apple orchard in Serbia, Poland, Austria and France were used to test the operation of LAPS in calculating surface fluxes and canopy environment temperatures within and above plant covers of different densities. In addition, sensitivity tests with single canopy covers over the Central Europe region and comparison against the observations taken from SYNOP data using 3D simulations were made. Validation of LAPS performances over a solid surface has been done by comparison of 2 m air temperature observations against 5-day simulations over the Sahara Desert rocky ground using 3D model. To examine how realistically the LAPS simulates surface processes over a heterogeneous surface, we compared the air temperature measured at 2 m and that predicted by the 1D model with the LAPS as the surface scheme. Finally, the scheme behaviour over urban surface was tested by runs over different parts of a hypothetical urban area. The corresponding 1D simulations were carried out with an imposed meteorological dataset collected during HAPEX-MOBILHY experiment at Caumont (France). The quantities predicted by the LAPS compare well with the observations and the various subcomponents of the scheme appear to operate realistically. 相似文献
102.
Diana Rodriguez Ana Rodriguez Amparo Soto Alfonso Aranda Yolanda Diaz-de-Mera Alberto Notario 《Journal of Atmospheric Chemistry》2008,59(3):187-197
The reactions of three structurally similar unsaturated alcohols, 2-buten-1-ol (crotyl alcohol), 2-methyl-2-propen-1-ol (MPO221)
and 3-methyl-2-buten-1-ol (MBO321) with Cl atoms, have been investigated for the first time, using a 400 l Teflon reaction
chamber coupled with gas chromatograph-coupled with flame-ionization detection (GC-FID). The experiments were performed at
atmospheric pressure and at temperatures between 255 and 298 K, in air or nitrogen as the bath gas. The obtained kinetic data
were used to derive the Arrhenius expressions , , (in units of cm3 molecule−1 s−1). Finally, atmospheric lifetimes of those unsaturated alcohols with respect to OH, NO3, O3 and Cl have been calculated. 相似文献
103.
J. Angel Fernández Angela Ares Ana Rey-Asensio Alejo Carballeira Jesus R. Aboal 《Journal of Atmospheric Chemistry》2009,63(1):1-11
The effects of growth of autoirrigated, shaded transplants of Pseudoscleropodium purum on the quantification of tissue concentrations of Cd, Cu, Hg, V and Zn, were investigated in 4 exposure periods, each of
56 days, at 7 sampling sites (contaminated and uncontaminated). Concentrations of the elements in the basal portions of the
moss shoots were compared with the concentrations in the portions of the shoots that grew during the exposure period. Mercury
and V were present at lower concentrations in the new portions of the shoots than in the basal portions, whereas the opposite
was true for Cd, Cu and Zn. The magnitude of error introduced by growth was not negligible, and in some cases was higher than
40%, relative to the results obtained by analysis of the whole shoot. Devitalization of moss prior to its use as transplant
material is recommended to avoid growth of the plant during the exposure period. 相似文献
104.
We present a numerical study of the set of orbits of the planar circular restricted three body problem which undergo consecutive
close encounters with the small primary, or orbits of second species. The value of the Jacobi constant is fixed, and we restrict
the study to consecutive close encounters which occur within a maximal time interval. With these restrictions, the full set
of orbits of second species is found numerically from the intersections of the stable and unstable manifolds of the collision
singularity on the surface of section that corresponds to passage through the pericentre. A ‘skeleton’ of this set of curves
can be computed from the solutions of the two-body problem. The set of intersection points found in this limit corresponds
to the S-arcs and T-arcs of Hénon’s classification which verify the energy and time constraints, and can be used to construct
an alphabet to describe the orbits of second species. We give numerical evidence for the existence of a shift on this alphabet
that describes all the orbits with infinitely many close encounters with the small primary, and sketch a proof of the symbolic
dynamics. In particular, we find periodic orbits that combine S-type and T-type quasi-homoclinic arcs. 相似文献
105.
Aaron GRONSTAL Victoria PEARSON Andreas KAPPLER Craig DOORIS Mahesh ANAND Franck POITRASSON Terence P. KEE Charles S. COCKELL 《Meteoritics & planetary science》2009,44(2):233-247
Abstract— Batch culture experiments were performed to investigate the weathering of meteoritic material by iron‐oxidizing bacteria. The aerobic, acidophilic iron oxidizer (A. ferrooxidans) was capable of oxidizing iron from both carbonaceous chondrites (Murchison and Cold Bokkeveld) and iron meteorites (York and Casas Grandes). Preliminary iron isotope results clearly show contrasted iron pathways during oxidation with and without bacteria suggesting that a biological role in meteorite weathering could be distinguished isotopically. Anaerobic iron‐oxidizers growing under pH‐neutral conditions oxidized iron from iron meteorites. These results show that rapid biologically‐mediated alteration of extraterrestrial materials can occur in both aerobic and anaerobic environments. These results also demonstrate that iron can act as a source of energy for microorganisms from both iron and carbonaceous chondrites in aerobic and anaerobic conditions with implications for life on the early Earth and the possible use of microorganisms to extract minerals from asteroidal material. 相似文献
106.
We identified 104 unique rock targets belonging to the olivine-rich Adirondack class using Mini-TES data. Rare rocks on the West Spur of the Columbia Hills and on the plains east of the Hills also belong to this class. We present evidence that Adirondack-class basaltic lavas may have had their origin at Apollinaris Tholus. Linear modeling of Adirondack-class rock spectra shows only minor variations in mineralogy and the primary phases identified are consistent with olivine basalt having an average olivine composition of ~Fo45. We used factor analysis and target transformation to identify variability within a single class of rocks for the first time, and we find that olivine abundance varies independently of a basaltic matrix. A spectral component previously attributed to downwelling radiance is proposed here to be attributable to optically thin dust on rocks, which has a greater effect on Mini-TES spectra than previously recognized, but can explain the sloping continuum observed in Adirondack-class rock spectra as well as the apparent distortion of an olivine absorption. Spectral mixing is not completely linear, leading to the overestimation of sulfate and olivine fractions and the underestimation of plagioclase feldspar, although linear mixing appears to successfully replicate the majority of the observed signal. Published TES spectra of low albedo, low dust cover, olivine-bearing materials do not exhibit the spectral telltales of non-linear behavior, probably because orbital spectra represent mostly mobile regolith that has not accumulated a sufficient dust cover over ~3 × 6 km areas. 相似文献
107.
We present the first spectra of Neptune taken with the Spitzer Space Telescope, highlighting the high-sensitivity, moderate-resolution 10-20 μm (500-1000 cm−1) spectra. We report the discovery of methylacetylene (CH3C2H) and diacetylene (C4H2) with derived 0.1-mbar volume mixing ratios of (1.2±0.1)×10−10 and (3±1)×10−12 respectively. 相似文献
108.
Martins Ana Rafael Sandra Monteiro Alexandra Scotto Manuel Gouveia Sónia 《Mathematical Geosciences》2019,51(8):1021-1035
Mathematical Geosciences - EURO-CORDEX is an international initiative which provides regional climate projections based on multiple dynamical and empirical–statistical downscaling models. The... 相似文献
109.
Alicia Correa Boris F Ochoa-Tocachi Christian Birkel Ana Ochoa-Sánchez Charles Zogheib Carolina Tovar Wouter Buytaert 《水文研究》2020,34(24):4609-4627
Páramos, a neotropical alpine grassland-peatland biome of the northern Andes and Central America, play an essential role in regional and global cycles of water, carbon, and nutrients. They act as water towers, delivering water and ecosystem services from the high mountains down to the Pacific, Caribbean, and Amazon regions. Páramos are also widely recognized as a biodiversity and climate change hot spots, yet they are threatened by anthropogenic activities and environmental changes. Despite their importance for water security and carbon storage, and their vulnerability to human activities, only three decades ago, páramos were severely understudied. Increasing awareness of the need for hydrological evidence to guide sustainable management of páramos prompted action for generating data and for filling long-standing knowledge gaps. This has led to a remarkably successful increase in scientific knowledge, induced by a strong interaction between the scientific, policy, and (local) management communities. A combination of well-established and innovative approaches has been applied to data collection, processing, and analysis. In this review, we provide a short overview of the historical development of research and state of knowledge of the hydrometeorology, flux dynamics, anthropogenic impacts, and the influence of extreme events in páramos. We then present emerging technologies for hydrology and water resources research and management applied to páramos. We discuss how converging science and policy efforts have leveraged traditional and new observational techniques to generate an evidence base that can support the sustainable management of páramos. We conclude that this co-evolution of science and policy was able to successfully cover different spatial and temporal scales. Lastly, we outline future research directions to showcase how sustainable long-term data collection can foster the responsible conservation of páramos water towers. 相似文献
110.