1,720,980 research outputs found
Projecting Northern and Central Italy Temperature and Precipitation Secular Records onto a high resolution grid
No full text1961-90 HIGH RESOLUTION TEMPERATURE, PRECIPITATION, AND SOLAR RADIATION CLIMATOLOGIES FOR ITALY
Full text linkThis PhD thesis focuses on the construction of monthly 30-arc-second resolution temperature, precipitation, and solar radiation 1961-90 climatologies for Italy and on the superimposition of the information of the secular anomaly records to these climatologies. The minimum, mean, and maximum temperature climatologies are based on a quality-checked new 1961-90 dataset for Italy that includes 1,493 TM records and 1,138 TN-TX records; they have been obtained by means of a Multiple Linear Regression model, plus local and global improvements and a Geographical Inverse Distance Gaussian Weighting of the residuals. The final monthly average MAE is 0.65 °C for TM, 0.91 °C for TN, 0.81 °C for TX. The precipitation climatologies are based on a quality-checked new 1961-90 dataset for Italy that includes more than 4,000 precipitation totals; they have been obtained by means of a PRISM model. The relative MAE for yearly total precipitation is approximately 10%. Further work is under development in order to improve both the database and the models. Examples of new reconstructed temperature and precipitation secular records for 1851-2010 are shown and the methodology used to obtain a secular record for each grid point is described. The solar radiation climatologies are obtained by means of a solar radiation model based on a quality-checked new dataset for Italy that includes more than 150 sunshine duration records. The solar radiation model is created on the basis of astronomical parameters, shading effects, albedo tables and turbidity Linke’s factor: monthly 1961-90 grids for direct, diffuse, reflected, absorbed, and global radiation are obtained. The final monthly average relative MAE is 4.6%
Analisi elementare e mineralogica di scorie di fusione di epoca romana provenienti dal sito di Piazza Marconi a Cremona
No full text
Projecting North East Italy temperature and precipitation secular records onto a high resolution grid
No full text1961–1990 monthly high-resolution solar radiation climatologies for Italy
Full text linkWe present a methodology for estimating solar radiation
climatologies from a sparse network of global radiation and/or sunshine
duration records: it allows to obtain high-resolution grids of monthly normal
values for global radiation (and for the direct and diffuse components),
atmospheric turbidity, and surface absorbed radiation. We discuss the
application of the methodology to a preliminary version of an Italian global
radiation and sunshine duration data set, which completion is still in
progress and present the resulting 1961–1990 monthly radiation
climatologies
High‐resolution temperature climatology for Italy: interpolation method intercomparison
No full textHigh-resolution monthly temperature climatologies for Italy are presented. They are based on a dense and quality-controlled observational dataset which includes 1484 stations and on three distinct approaches: multi-linear regression with local improvements (MLRLI), an enhanced version of the model recently used for the Greater Alpine Region, regression kriging (RK), widely used in literature and, lastly, local weighted linear regression (LWLR) of temperature versus elevation, which may be considered more suitable for the complex orography characterizing the Italian territory. Dataset and methods used both to check the station records and to get the 1961-1990 normals used for the climatologies are discussed. Advantages and shortcomings of the three approaches are investigated and the results are compared. All three approaches lead to quite reasonable models of station temperature normals, with lowest errors in spring and autumn and highest errors in winter. The LWLR approach shows slightly better performances than the other two, with monthly leave-one-out estimated root mean square errors ranging from 0.74°C (April and May) to 1.03°C (December). Further evidence in its favour is the greater reliability of local approach in modelling the behaviour of the temperature-elevation relationship in Italy's complex territory. The comparison of the different climatologies is a very effective tool to understand the robustness of each approach. Moreover, the first two methods (MLRLI and RK) turn out to be important to tune the third one (LWLR), as they help not only to understand the relationship between temperature normals and some important physiographical variables (MLRLI) but also to study the decrease of station normals covariance with distance (RK). © 2013 The Authors. International Journal of Climatology published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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