919 research outputs found

    Fostering Intercultural Competencies Through Global Awareness and Immersion

    Get PDF
    Among the many changes in the world today is the growth in the interrelatedness of people and cultures across nations. This change makes intercultural competence skills even more important for higher education students, especially in the United States, as they will be entering an increasingly multicultural and diverse workplace. Beginning with an understanding of global awareness achieved on university campuses, educators can work towards preparing students to succeed in an internationalized economy and strive towards creating students that are motivated to take actions closer to world peace. Furthermore, universities can immerse their students in other cultures through study abroad programming to strengthen student appreciation of their own and other cultures across borders

    Tropospheric and stratospheric aspects of the North Atlantic Oscillation: An eddy perspective

    Get PDF
    Recent studies have described the leading patterns of variability of the Northern Hemisphere extratropical circulation as an annular structure. The associated sea-level winter feature resembles the North Atlantic Oscillation pattern; however, it has been noticed that its centers of action, covering most of the Arctic, have a more zonally symmetric structure. This mode has been referred as the Arctic Oscillation (AO). By considering the vertical structure of the AO, some authors have suggested that a stratosphere-troposphere interaction mechanism may be the source of the interannual variability associated with the AO and, therefore, it could have some relevances also for the NAO. Thus, the NAO and the AO may be considered as different facets of the same phenomenon. In the present paper we analyze the interannual variability of 52 Northern hemisphere winters in the NCEP reanalysis. The study rests on a principal component analysis and singular value decomposition of the sea level pressure, the geopotential heights at 500 hPa and 50 hPa and the zonal wind at 200 hPa. Moreover, following Rossby earlier works, we compute the principal components also for the eddy fields. The analysis performed suggests that the eddy patterns of variability allow a better identification of the modes connected to the NAO in the middle troposphere and in the lower stratosphere. Two distinct stratospheric wave patterns are found to be related to NAO and PNA modes. The covariance analysis suggests a dynamical link with the Atlantic jet exit for the former mode, and a connection with the Atlantic jet entrance for the latter mode. In view of the NAO-AO debate, the results here presented seem to confirm that the NAO and PNA mechanisms contribute separately to the atmospheric eddies variability in the troposphere and in the lower stratosphere

    An analysis of drought in Italy in the last fifty years

    Get PDF
    In this paper the authors present a study of drought occurrence over Italy. The NCEP/NCAR reanalysis precipitation rates covering the period from 1948 to 2000 were used to assess drought over the area in question. The analysis is based on the Standardized Precipitation Index (SPI), which has been proposed asan indicator of drought occurrence. The index relieson the knowledge of the precipitation field only, therefore, it may be readily computed from the data. A Principal Component Analysis (PCA) of the resulting fields reveals a downward trend for the index over the area considered. It implies that drought conditions have been in the recent past more frequent and extended, within the region, over larger areas. Moreover, the temporal behaviours of the principal component scores show few long-term periodicities

    Equilibration of a two-level primitive equation model on the sphere

    Get PDF
    The equilibration of a two-level primitive equation model forced by relaxation towards a fixed axisymmetric temperature profile is studied as a function of the forcing equator-to-pole temperature difference. We find that the mean equilibrated temperature gradient rises quickly with the forcing. It is found also that the mean eddy momentum flux convergence induces a strong barotropic jet at mid-to-high latitudes. We suggest that, as found in previous work, the barotropic governor effect induced by the jet is responsible for the sensitivity of the equilibrated temperature gradient to the forcing

    Multiple jets observed in the summer Northern Hemisphere troposphere

    Get PDF
    Daily observations of the Northern Hemisphere zonal mean zonal wind during July show an intermittent formation of multiple tropospheric jet streams. In particular, a tropospheric westerly, or easterly, jet occurs at latitudes greater than 75◦N: it co-exists with the mid-latitude jet and is characterized by variability on synoptic time scale. Two sample years are here considered, July 1996 and July 1985, when prevailing westerly and easterly jets occur at high latitudes, respectively. Analysis is consistent with a picture where the physical mechanism, which creates and maintains the polar jet in the summer troposphere, is the baroclinic instability process acting on a westerly, or easterly, background zonal flow. Due to the synoptic variability, monthly mean maps of the zonal mean zonal wind for July may show different jet patterns as a function of the year, depending on the occurrences (number and duration) of westerly or easterly polar jets within each month considered. The study of the inter-annual variability of the zonal mean zonal wind through the principal component analysis indicates, in fact, that three tropospheric jet stream patterns can be distinguished. Consistency of observations with the available theories on the double-jet formation is provided and the impact of polar jet occurrences on surface temperature field is evaluated

    Equilibration of a two-level primitive equation model on the sphere

    Get PDF
    The equilibration of a two-level primitive equation model forced by relaxation towards a fixed axisymmetric temperature profile is studied as a function of the forcing equator-to-pole temperature difference. We find that the mean equilibrated temperature gradient rises quickly with the forcing. It is found also that the mean eddy momentum flux convergence induces a strong barotropic jet at mid-to-high latitudes. We suggest that, as found in previous work, the barotropic governor effect induced by the jet is responsible for the sensitivity of the equilibrated temperature gradient to the forcing

    A Numerical Evaluation of the Stochastic Completeness of the Kinetic Coagulation Equation

    Get PDF
    The stochastic completeness of the kinetic coagulation equation depends on the extent of correlations between particle properties. Such correlations are induced by the coalescence process that causes spatial inhomogeneities in the number concentration of the particles, and are particularly strong in poorly mixed suspensions. A Monte Carlo simulation of the coalescence process is used to evaluate the suitability of the kinetic coagulation equation to simulate the coalescence process using Brownian diffusion, fluid shear and differential sedimentation collision kernels. It is demonstrated that the outcome of the kinetic equation matches well the true stochastic averages, unless the number concentration of particles involved is very small. In that case, the discrepancies between the two approaches are substantial in the large end of the particle size spectrum

    Multiple jets observed in the summer Northern Hemisphere troposphere

    Get PDF
    Daily observations of the Northern Hemisphere zonal mean zonal wind during July show an intermittent formation of multiple tropospheric jet streams. In particular, a tropospheric westerly, or easterly, jet occurs at latitudes greater than 75◦N: it co-exists with the mid-latitude jet and is characterized by variability on synoptic time scale. Two sample years are here considered, July 1996 and July 1985, when prevailing westerly and easterly jets occur at high latitudes, respectively. Analysis is consistent with a picture where the physical mechanism, which creates and maintains the polar jet in the summer troposphere, is the baroclinic instability process acting on a westerly, or easterly, background zonal flow. Due to the synoptic variability, monthly mean maps of the zonal mean zonal wind for July may show different jet patterns as a function of the year, depending on the occurrences (number and duration) of westerly or easterly polar jets within each month considered. The study of the inter-annual variability of the zonal mean zonal wind through the principal component analysis indicates, in fact, that three tropospheric jet stream patterns can be distinguished. Consistency of observations with the available theories on the double-jet formation is provided and the impact of polar jet occurrences on surface temperature field is evaluated

    Observed drought and wetness trends in Europe: an update

    Get PDF
    Abstract. Linear and nonlinear trends of drought and wetness are analysed in terms of the gridded Standardized Precipitation Index (SPI) determined from monthly precipitation in Europe (NCEP/NCAR). In characterizing the meteorological and hydrological aspects, the index is computed on a seasonal and on a bi-annual time scale. Two datasets are compared: one from 1949 to 1997 and the other one includes the update of the last decade (to February 2009). The following results are noted: (i) time series of drought and wetness area coverage (number of grid points above/below the severity threshold) show a remarkable linear trend until about the end of the last century, which is reversed in the last (update) decade. This recent trend reversal is an indication of a nonlinear trend, which is more pronounced on the hydrological time scale. (ii) A nonlinear trend analysis is performed based on the time series of the principal component (PC) associated to the first spatial SPI-eigenvector after embedding it in a time delay coordinate system using a sliding window of 70 months (singular spectrum analysis). Nonlinearity appears as a clear feature on the hydrological time scale. (iii) The first spatial EOF-patterns of the shorter and the longer (updated) SPI time series fields show similar structure. An inspection of the SPI time behaviour at selected grid points illustrates the spatial variability of the detected trends

    A combined genome-wide approach identifies a new potential candidate marker associated with the coat color sidedness in cattle

    Get PDF
    Coat color is one of the most important phenotypic features in livestock breeds. Cinisara is a local cattle breed generally of uniform black color which occasionally presents a particular phenotype, with animals typically display a white band along their spine, from the head to the tail, and on the ventral line (color sidedness). Therefore, this breed provides an ideal model to study the genetic components underlying phenotypic variation in coat color. A total of 63 animals, ten with sidedness phenotype and 53 with uniform black color were genotyped with Illumina Bovine 50 K. The comparison among genome-wide association study and FST analysis revealed a single nucleotide polymorphism (SNP), ARS-BFGL-NGS-55928, significantly associated with the trait. Only one gene (PLK2)was annotated near the associated SNP in a window of ±200 kb. The protein encoded by this gene is a member of the polo-like kinases, the same family of several known coat-color candidate genes. Based on the reported results, we draw the possible conclusion that the identified marker is potentially associated with the coat color sidedness in Cinisara. The local breeds with their genetic variability represent an important resource and model to study the genetic basis affecting peculiar traits. Future studies would be particularly relevant to refine these results and to better understand the genetic basis for this phenotype
    corecore