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During the last few decades, weather circulation type classi?cations (CTCs) have been widely used to gaininsight into processes at the synoptic scale, but also for studying the relationship between atmospheric circulation and surfaceclimate variability. This study aims to evaluate the best performing CTCs based on COST733 software for the strati?cation ofdaily ground-level precipitation and surface air temperature across Italy by means of four statistical metrics. Six classi?cationmethods belonging to the four COST733 groups (threshold-based, PCA-based, leader algorithms and optimization algorithms)were investigated on 32 and 26 data time series derived from Italian weather stations for daily mean temperature and daily meanprecipitation, respectively. CTCs were computed using gridded mean sea level pressure and geopotential height at 500 hPaderived from the NCEP Reanalysis 2 dataset between 1979 and 2015 and tested on three different numbers of classes (8/9, 11/12and 18 circulation types). Evaluation metrics showed an evident seasonal variability and high-spatial heterogeneity re?ectingthe geographical complexity of the Italian territory. The study points out that the best classi?cation, both for temperature andprecipitation, is strongly dependent on the classi?cation variable (mean sea level pressure and geopotential height at 500 hPa)showing relevant differences between surface temperature and precipitation. A low number of circulation types (8/9) resultedas the most appropriate grouping for the Italian domain and the Principal Component Transversal and Simulated Annealingwere the best performing classi?cation procedures for ground-level precipitation and temperature strati?cation, respectively.

Quality System of the International Towing Tank Conference

Dictionary of Hydromechanics -prepared by the Quality Systems Group of the 28th ITTC

Yonagunia, a genus of the red algal order Halymeniales, has never been recorded in the Western Indian Ocean. In this study, we used molecular assisted alpha taxonomy to assess the diversity of the marine algal flora of southern Madagascar. A combination of COI-5P and rbcL sequences, used as a DNA-barcode and phylogenetic marker respectively, revealed two species of Yonagunia from the Toliara region in the South of Madagascar. One species, is described a species new to science, Yonagunia atimo-vatae sp. nov. Sequences of the other species, matched of Polyopes ligulata, but it was resolved within the genus Yonagunia rather than Polyopes. Hence, a new combination Yonagunia ligulata comb. nov. is established.

Solar radiation affects human beings in different ways with direct effects occurring when people are exposed outdoors during working or leisure/sport activities. Erythema is the most familiar short-term symptom of human skin associated with overexposure to unperceivable ultraviolet radiation (UV). In this study the newly developed Universal Thermal Climate Index (UTCI) will be used for the first time to investigate whether the perceived outdoor heat stress might represent a valuable proxy for the unperceivable effect of UV-induced risk of erythema in a Mediterranean city, Florence, Tuscany (Central Italy). The aim of this study is therefore to propose a real approach to link solar UV radiation and thermal factors by means of the application of two internationally recognized indices, in order to estimate their reciprocal interaction and the potential impact on human health. Meteorological data and UVB (280-320 nm) measurements were obtained for the 2004-2012 period by a weather station located in the municipality of Florence. The UTCI was assessed and continuous measurements of erythemally effective UV (UVEry) were performed by means of broadband temperature-corrected radiometers with the spectral response close to the erythemal action spectrum. Hourly UVEry doses were expressed as Standard Erythemal Doses (SEDs). Descriptive analyses of the hourly distribution per month of the frequencies of days with heat stress and UVEry exceeding 2.0, 3.0, 4.5 and 6.0 SEDs were carried out based on the general skin-type characteristics. The association between UVEry and UTCI was analyzed by a two-way contingency table approach. The probability of UVEry exceeding specific SED thresholds when heat stress occurs was often significantly higher than the same probability when no heat stress is perceived. However, during several months, too many days occur without any signs of heat discomfort, even when people may be exposed to relevant doses of harmful UVEry for the skin of various phototypes. These findings underlie the need for public health authorities to provide differentiated advice per month in relation to potential UV skin damage in the city of Florence. Such specific UV information is fundamental for educating the local population and tourists and making them aware of sun exposure.

Thermal comfort is a topic of particular interest for experts, such as urban planners, architects, biometeorologists and physicians, dealing with quality of life of people living in urban areas. It is well known that thermal comfort is influenced by urban design at the micro-scale and features like the presence of parks and street canyon can influence micrometeorological variables that control the human thermal sensation. This study deals with urban human-biometeorology on the micro-scale, and its main purpose is to quantify the intra-urban thermal comfort variability of the city of Florence and investigate the influence of green area. Steadman heat Index, Humidex and Thom Discomfort Index were calculated from meteorological variables collected by 15 sensors distributed in Florence urban area during summer 2010. Seasonal and hourly average were analysed and compared with the percentage of green areas nearby the sensors. The average number of discomfort hours in Florence was approximately 891 hours for Steadman heat Index, 1485 hours for Humidex and 1605 hours for Thom Discomfort Index, with a maximum discomfort difference between the hottest and the coolest station of respectively 541, 464 and 402 hours. Discomfort variability was significantly correlated with the percentage of green areas surrounding the sensor and a 10% increase of green area determine approximately a reduction of 30 hours of discomfort according to all indices. All these results show that citizens living in the same city may be subjected to different level of discomfort according to the local urban characteristics of the place where they live and underline the importance of future studies that can provide tools to assess the impact of urbanisation on quality of life and health.