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Pezzoli A.,Polytechnic University of Turin | Pezzoli A.,University of Turin | Cristofori E.,Polytechnic University of Turin | Cristofori E.,University of Turin | And 4 more authors.
Procedia Engineering | Year: 2012

This research presents a detailed analysis of thermal comfort in road cycling athletes. The data have been collected during experimental road test in prevision of the UCI Road World Championship 2013 (Florence-Tuscany, Italy), considering the different technical situations and the different environmental conditions expected as the most probable for the race's period. The analysis presented in this work is based on the in-situ measurements of both environmental and physiological parameters (i.e.: air temperature, relative humidity, true wind velocity, apparent wind velocity, skin temperature, clothing temperature, heat transfer resistance of the clothing, internal heat production) made over different athletes in different race conditions. The recorded data have been used as input for the model "RayMan" [1],[2] for the assessment of the thermal comfort using thermal indices such as Predicted Mean Vote (PMV) and Physiological Equivalent Temperature (PET). It should be noted that the apparent wind velocity, which is a fundamental parameter in this kind of analysis but often disregarded, is evaluated in relationship with the movement and the effort made by the cyclist. The results obtained by the comparison of the PET and PMV indices with the measured skin temperature confirm the importance of considering the variation of environmental parameters in both training and strategy assessment and provide a working method which is believed to be innovative for the applied sport research. © 2012 Published by Elsevier Ltd. Source

Xia J.,University of Oklahoma | Niu S.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Ciais P.,French Climate and Environment Sciences Laboratory | Janssens I.A.,University of Antwerp | And 43 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate-carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of biotic and abiotic factors operating mainly through changes in vegetation phenology and physiological processes. However, it is still unclear howplant phenology and physiology can be integrated to explain the spatiotemporal variability of terrestrial GPP. Based on analyses of eddy-covariance and satellite-derived data, we decomposed annual terrestrial GPP into the length of the CO2 uptake period (CUP) and the seasonalmaximal capacity of CO2 uptake (GPPmax). The product of CUP and GPPmax explained >90% of the temporal GPP variability in most areas of North America during 2000-2010 and the spatial GPP variation among globally distributed eddy flux tower sites. It also explained GPP response to the European heatwave in 2003 (r2 = 0.90) and GPP recovery after a fire disturbance in South Dakota (r2 = 0.88). Additional analysis of the eddy-covariance flux data shows that the interbiome variation in annual GPP is better explained by that in GPPmax than CUP. These findings indicate that terrestrial GPP is jointly controlled by ecosystem-level plant phenology and photosynthetic capacity, and greater understanding of GPPmax and CUP responses to environmental and biological variations will, thus, improve predictions of GPP over time and space. Source

Osti F.,Institute of Biometeorology | Di Marco S.,Institute of Biometeorology
Acta Horticulturae | Year: 2011

Wood decay is a recent chronic wood disease caused by different fungi with a complex aetiology not clear. This harmful and spread disease is characterized by a correlation between yield losses and oliar symptoms, which in turn have an erratic nature as esca of grapevine. A survey is being carried out on 10-year-old, in which wood decay appeared for the first time in 2003. Each year and in each, the incidence of the disease was assessed by recording the percentage of vines with foliar symptoms. Moreover, in each vineyard the content of exchangeable sodium in the soil was evaluated. Source

Dalu G.A.,Institute of Biometeorology | Baldi M.,Institute of Biometeorology
Journal of the Atmospheric Sciences | Year: 2010

The authors study the nonlinear dynamics of a density current generated by a diabatic source in a rotating and a nonrotating system, both in the presence and in the absence of frictional losses, using a steady-state hydrostatic shallow-water model and producing solutions as a function of the Coriolis parameter and of the Rayleigh friction coefficient. Results are presented in the range of the parameter values that are relevant for shallow atmospheric flows as sea-land breezes and as cold pool outflows. In the shallow-water approximation, single-layer flows and two-layer flows with a lid have three degrees of freedom, and their steady-state dynamics are governed by three ordinary differential equations (ODEs), whereas two-layer flows bounded by a free surface have six degrees of freedom, and their dynamics are governed by six ODEs. It is shown that in the limit case of frictionless flow, the problem has an explicit analytical solution, and in the presence of friction, the system for a one-layer flow and for a two-layer flow bounded by a lid can be reduced to two algebraic equations, plus one second-order ordinary differential equation, which can be integrated numerically. Results show that the maximum runout length of the current occurs when the Rayleigh friction coefficient in the lower layer is on the order of the Coriolis parameter. This length is larger when the upper layer is deeper than the lower layer, but it shortens when the friction coefficient of the upper layer is smaller than that in the lower layer. In addition, the relative error of the solution to the linearized equations is computed. This error, which is enhanced when the width of the forcing is smaller than the Rossby radius, is sizable when the friction coefficient is smaller than the Coriolis parameter. In addition, by comparing the nonlinear solution with a lid (three degrees of freedom) to the nonlinear solution with a free surface as an upper boundary (six degrees of freedom), it is shown that the solution with the lid overestimates the geopotential for low values of the friction coefficient and it underestimates the geopotential for large values of this coefficient. The error, sizable when the two layers have a comparable depth, rapidly decreases when the upper layer becomes deeper than the lower layer; accordingly, a rigid lid can be safely adopted only when the depth of the upper layer is twice the depth of the lower layer, or deeper. © 2010 American Meteorological Society. Source

Salinger M.J.,Institute of Biometeorology | Baldi M.,Institute of Biometeorology | Grifoni D.,CNR Institute of Neuroscience | Jones G.,Southern Oregon University | And 7 more authors.
International Journal of Biometeorology | Year: 2015

Climatic factors and weather type frequencies affecting Tuscany are examined to discriminate between vintages ranked into the upper- and lower-quartile years as a consensus from six rating sources of Chianti wine during the period 1980 to 2011. These rankings represent a considerable improvement on any individual publisher ranking, displaying an overall good consensus for the best and worst vintage years. Climate variables are calculated and weather type frequencies are matched between the eight highest and the eight lowest ranked vintages in the main phenological phases of Sangiovese grapevine. Results show that higher heat units; mean, maximum and minimum temperature; and more days with temperature above 35 °C were the most important discriminators between good- and poor-quality vintages in the spring and summer growth phases, with heat units important during ripening. Precipitation influences on vintage quality are significant only during veraison where low precipitation amounts and precipitation days are important for better quality vintages. In agreement with these findings, weather type analysis shows good vintages are favoured by weather type 4 (more anticyclones over central Mediterranean Europe (CME)), giving warm dry growing season conditions. Poor vintages all relate to higher frequencies of either weather type 3, which, by producing perturbation crossing CME, favours cooler and wetter conditions, and/or weather type 7 which favours cold dry continental air masses from the east and north east over CME. This approach shows there are important weather type frequency differences between good- and poor-quality vintages. Trend analysis shows that changes in weather type frequencies are more important than any due to global warming. © 2015 ISB Source

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